Update change log and tag 2.4.1

Disable old version before copying files
Apparently some people still have the obsolete v1.5.1 installed and manage to break things by copying v2.x config in place.
2025-12-07 09:36:10 -08:00 · 2024-04-11 17:48:55 +03:00 · 2024-04-11 17:46:13 +03:00 · 2024-04-11 17:46:13 +03:00 · 2024-03-24 17:27:02 +02:00 · 2024-01-20 12:43:00 +02:00
26 changed files with 1321 additions and 241 deletions
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -0,0 +1,21 @@
+---
+name: Bug report
+about: Create a report if you encounter a bug
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**What happens?**
+Describe the bug.
+
+**How this happens?**
+Explain exactly the steps you did:
+1. Download HackBGRT-(version).zip and extract all files.
+2. Start setup.
+3. Select ...
+4. ...
+
+**Log file**
+Run the setup again and select menu option `L` (or add parameter `show-boot-log` on command line). Attach the `setup.log` to this report.
--- a/.gitmodules
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "gnu-efi"]
+	path = gnu-efi
+	url = https://github.com/rhboot/gnu-efi.git
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,42 @@

 All notable changes to this project will be documented in this file.

+## 2.4.1 - 2024-04-11
+
+### Fixed
+- Report better if BCDEdit is unable to operate.
+- Improve support for non-BCDEdit boot entries.
+- Remove old version before copying any new files.
+
+## 2.4.0 - 2023-12-31
+
+### Fixed
+- Fix BCDEdit boot entries to avoid *shim* error messages.
+- Combine BCDEdit and own code to create boot entries more reliably.
+
+### Changed
+- Clear the screen to wipe the vendor logo as soon as possible.
+- Image paths in `config.txt` may be relative (just file names).
+
+## 2.3.1 - 2023-11-27
+
+### Fixed
+- BitLocker detection is more reliable.
+
+## 2.3.0 - 2023-11-27
+
+### Added
+- AArch64 and ARM builds, and *shim* for AArch64.
+
+### Fixed
+- Boot entry is more reliable, avoids conflicts with firmware entries.
+
+## 2.2.0 - 2023-11-17
+
+### Added
+- Support Secure Boot with *shim* boot loader.
+- Gather debug log during boot and read it with setup.exe.
+
 ## 2.1.0 - 2023-10-04

 ### Added
--- a/136
+++ b/136
@@ -1,44 +1,122 @@
-CC      = $(CC_PREFIX)-gcc
-CFLAGS  = -std=c11 -O2 -ffreestanding -mno-red-zone -fno-stack-protector -Wshadow -Wall -Wunused -Werror-implicit-function-declaration -Werror
+CC = clang
+CFLAGS = -target $(CLANG_TARGET) -ffreestanding -fshort-wchar
+CFLAGS += -std=c17 -Wshadow -Wall -Wunused -Werror-implicit-function-declaration
 CFLAGS += -I$(GNUEFI_INC) -I$(GNUEFI_INC)/$(GNUEFI_ARCH) -I$(GNUEFI_INC)/protocol
-LDFLAGS = -nostdlib -shared -Wl,-dll -Wl,--subsystem,10 -e _EfiMain
-LIBS    = -L$(GNUEFI_LIB) -lefi -lgcc
+CFLAGS += $(ARCH_CFLAGS)
+LDFLAGS = -target $(CLANG_TARGET) -nostdlib -Wl,-entry:efi_main -Wl,-subsystem:efi_application -fuse-ld=lld
+ARCH_CFLAGS = -O2 -mno-red-zone

-GNUEFI_INC = /usr/$(CC_PREFIX)/include/efi
-GNUEFI_LIB = /usr/$(CC_PREFIX)/lib
+GNUEFI_INC = gnu-efi/inc

-FILES_C = src/main.c src/util.c src/types.c src/config.c
+FILES_C = src/main.c src/util.c src/types.c src/config.c src/sbat.c src/efi.c
 FILES_H = $(wildcard src/*.h)
 FILES_CS = src/Setup.cs src/Esp.cs src/Efi.cs
-GIT_DESCRIBE = $(firstword $(shell git describe --tags) unknown)
-CFLAGS += '-DGIT_DESCRIBE=L"$(GIT_DESCRIBE)"'
-ZIPDIR = HackBGRT-$(GIT_DESCRIBE:v%=%)
-ZIP = $(ZIPDIR).zip
+GIT_DESCRIBE := $(firstword $(GIT_DESCRIBE) $(shell git describe --tags) unknown)
+CFLAGS += '-DGIT_DESCRIBE_W=L"$(GIT_DESCRIBE)"' '-DGIT_DESCRIBE="$(GIT_DESCRIBE)"'
+RELEASE_NAME = HackBGRT-$(GIT_DESCRIBE:v%=%)
+
+EFI_ARCH_LIST = x64 ia32 aa64 arm
+EFI_SIGNED_FILES = $(patsubst %,efi-signed/boot%.efi,$(EFI_ARCH_LIST))
+
+.PHONY: all efi efi-signed setup release clean
+
+all: efi setup
+	@echo "Run 'make efi-signed' to sign the EFI executables."
+	@echo "Run 'make release' to build a release-ready ZIP archive."
+	@echo "Run 'make run-qemu-<arch>' to test the EFI executables with QEMU."
+
+efi: $(patsubst %,efi/boot%.efi,$(EFI_ARCH_LIST))
+	@echo "EFI executables are in the efi/ directory."
+
+efi-signed: $(patsubst %,efi-signed/boot%.efi,$(EFI_ARCH_LIST))
+	@echo "Signed EFI executables are in the efi-signed/ directory."

-all: efi setup zip
-efi: bootx64.efi bootia32.efi
 setup: setup.exe

-zip: $(ZIP)
-$(ZIP): bootx64.efi bootia32.efi config.txt splash.bmp setup.exe README.md CHANGELOG.md README.efilib LICENSE
-	test ! -d "$(ZIPDIR)"
-	mkdir "$(ZIPDIR)"
-	cp -a $^ "$(ZIPDIR)" || (rm -rf "$(ZIPDIR)"; exit 1)
-	7z a -mx=9 "$(ZIP)" "$(ZIPDIR)" || (rm -rf "$(ZIPDIR)"; exit 1)
-	rm -rf "$(ZIPDIR)"
+release: release/$(RELEASE_NAME).zip
+	@echo "Current version is packaged: $<"
+
+release/$(RELEASE_NAME): $(EFI_SIGNED_FILES) certificate.cer config.txt splash.bmp setup.exe README.md CHANGELOG.md README.efilib LICENSE shim-signed/* shim.md
+	rm -rf $@
+	tar c --transform=s,^,$@/, $^ | tar x
+
+release/$(RELEASE_NAME).zip: release/$(RELEASE_NAME)
+	rm -rf $@
+	(cd release; 7z a -mx=9 "$(RELEASE_NAME).zip" "$(RELEASE_NAME)" -bd -bb1)

 src/GIT_DESCRIBE.cs: $(FILES_CS) $(FILES_C) $(FILES_H)
 	echo 'public class GIT_DESCRIBE { public const string data = "$(GIT_DESCRIBE)"; }' > $@

 setup.exe: $(FILES_CS) src/GIT_DESCRIBE.cs
-	csc /define:GIT_DESCRIBE /out:$@ $^
+	csc /nologo /define:GIT_DESCRIBE /out:$@ $^

-bootx64.efi: CC_PREFIX = x86_64-w64-mingw32
-bootx64.efi: GNUEFI_ARCH = x86_64
-bootx64.efi: $(FILES_C)
-	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ $(LIBS) -s
+certificate.cer pki:
+	@echo
+	@echo "You need proper keys to sign the EFI executables."
+	@echo "Example:"
+	@echo "mkdir -p pki"
+	@echo "certutil --empty-password -N -d pki"
+	@echo "efikeygen -d pki -n HackBGRT-signer -S -k -c 'CN=HackBGRT Secure Boot Signer,OU=HackBGRT,O=Unknown,MAIL=unknown@example.com' -u 'URL'"
+	@echo "certutil -d pki -n HackBGRT-signer -Lr > certificate.cer"
+	@echo "Modify and run the commands yourself."
+	@echo
+	@false

-bootia32.efi: CC_PREFIX = i686-w64-mingw32
-bootia32.efi: GNUEFI_ARCH = ia32
-bootia32.efi: $(FILES_C)
-	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ $(LIBS) -s
+efi-signed/%.efi: efi/%.efi pki
+	@mkdir -p efi-signed
+	pesign --force -n pki -i $< -o $@ -c HackBGRT-signer -s
+
+efi/bootx64.efi: CLANG_TARGET = x86_64-pc-windows-msvc
+efi/bootx64.efi: GNUEFI_ARCH = x86_64
+
+efi/bootia32.efi: CLANG_TARGET = i386-pc-windows-msvc
+efi/bootia32.efi: GNUEFI_ARCH = ia32
+
+efi/bootaa64.efi: CLANG_TARGET = aarch64-pc-windows-msvc
+efi/bootaa64.efi: GNUEFI_ARCH = aa64
+
+efi/boot%.efi: $(FILES_C)
+	@mkdir -p efi
+	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@
+
+efi/bootarm.efi: CLANG_TARGET = armv6-pc-windows-msvc
+efi/bootarm.efi: GNUEFI_ARCH = arm
+efi/bootarm.efi: ARCH_CFLAGS = -O # skip -O2 and -mno-red-zone
+efi/bootarm.efi: $(FILES_C)
+	@mkdir -p efi
+	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@
+	@echo "Fix $@ architecture code (IMAGE_FILE_MACHINE_ARMTHUMB_MIXED = 0x01C2)"
+	echo -en "\xc2\x01" | dd of=$@ bs=1 seek=124 count=2 conv=notrunc status=none
+
+clean:
+	rm -rf setup.exe efi efi-signed
+	rm -f src/GIT_DESCRIBE.cs
+	rm -rf release
+	rm -rf test
+
+.PHONY: test $(patsubst %,run-qemu-%,$(EFI_ARCH_LIST))
+
+test: run-qemu-x64
+	@echo "Run 'make run-qemu-<arch>' to test other architectures."
+
+test/esp-%: efi/boot%.efi splash.bmp
+	rm -rf $@
+	mkdir -p $@/EFI/HackBGRT
+	cp efi/boot$*.efi splash.bmp $@/EFI/HackBGRT
+	echo -en "FS0:\n cd EFI\n cd HackBGRT\n boot$*.efi resolution=-1x-1 debug=1 image=path=splash.bmp" > $@/startup.nsh
+
+QEMU_ARGS = -bios $(word 2, $^) -net none -drive media=disk,file=fat:rw:./$<,format=raw
+
+run-qemu-x64: test/esp-x64 /usr/share/ovmf/x64/OVMF.fd
+	qemu-system-x86_64 $(QEMU_ARGS)
+
+run-qemu-ia32: test/esp-ia32 /usr/share/ovmf/ia32/OVMF.fd
+	qemu-system-i386 $(QEMU_ARGS)
+
+run-qemu-aa64: test/esp-aa64 /usr/share/ovmf/aarch64/QEMU_EFI.fd
+	@echo "Press Ctrl+Alt+2 to switch to QEMU console."
+	qemu-system-aarch64 -machine virt -cpu max $(QEMU_ARGS)
+
+run-qemu-arm: test/esp-arm /usr/share/ovmf/arm/QEMU_EFI.fd
+	@echo "Press Ctrl+Alt+2 to switch to QEMU console."
+	qemu-system-arm -machine virt -cpu max $(QEMU_ARGS)
--- a/README.md
+++ b/README.md
@@ -6,23 +6,31 @@ HackBGRT is intended as a boot logo changer for UEFI-based Windows systems.

 When booting on a UEFI-based computer, Windows may show a vendor-defined logo which is stored on the UEFI firmware in a section called Boot Graphics Resource Table (BGRT). It's usually very difficult to change the image permanently, but a custom UEFI application may be used to overwrite it during the boot. HackBGRT does exactly that.

+**Note:** The original logo is often visible for a moment before HackBGRT is started. This is expected, please do not report this "bug". This can't be changed without modifying computer firmware, which this project will not do.
+
 ## Usage

 **Important:** If you mess up the installation, your system may become unbootable! Create a rescue disk before use. This software comes with no warranty. Use at your own risk.

 * Make sure that your computer is booting with UEFI.
-* Make sure that Secure Boot is disabled, unless you know how to sign EFI applications.
+* Make sure that you have read the Secure Boot instructions.
 * Make sure that BitLocker is disabled, or find your recovery key.

+### Secure Boot instructions
+
+HackBGRT is not approved by Microsoft. Instead, HackBGRT comes with the *shim* boot loader, which allows to manually select HackBGRT as a trusted program. After installing HackBGRT and rebooting your computer, you have to **follow the instructions in [shim.md](shim.md)** to achieve this. These steps cannot be automated, that's the whole point of Secure Boot. Although HackBGRT is self-signed with a certificate, it's not advisable to enroll foreign certificates directly into your firmware.
+
+The *shim* boot loader is maintained by Red Hat, Inc, and the included signed copy of *shim* is extracted from Debian GNU/Linux – many thanks to the maintainers! For copyright information, see [shim-signed/COPYRIGHT](shim-signed/COPYRIGHT).
+
 ### Windows installation

 * Get the latest release from the Releases page.
 * Start `setup.exe` and follow the instructions.
-	* You may need to manually disable Secure Boot and then retry.
 	* The installer will launch Paint for editing the image.
 	* If Windows later restores the original boot loader, just reinstall.
 	* If you wish to change the image or other configuration, just reinstall.
 	* For advanced settings, edit `config.txt` before installing. No extra support provided!
+	* After installing, read the instructions in [shim.md](shim.md) and reboot your computer.

 ### Quiet (batch) installation

@@ -35,11 +43,13 @@ When booting on a UEFI-based computer, Windows may show a vendor-defined logo wh
 	* `disable-bootmgr` – use `bcdedit` to disable the EFI boot entry.
 	* `enable-overwrite` – overwrite the MS boot loader.
 	* `disable-overwrite` – restore the MS boot loader.
+	* `skip-shim` – skip *shim* when installing.
 	* `allow-secure-boot` – ignore Secure Boot in subsequent commands.
 	* `allow-bitlocker` – ignore BitLocker in subsequent commands.
 	* `allow-bad-loader` – ignore bad boot loader configuration in subsequent commands.
 	* `disable` – run all relevant `disable-*` commands.
 	* `uninstall` – disable and remove completely.
+	* `show-boot-log` – show the debug log collected during boot (if `log=1` is set in `config.txt`).
 * For example, run `setup.exe batch install allow-secure-boot enable-overwrite` to copy files and overwrite the MS boot loader regardless of Secure Boot status.

 ### Multi-boot configurations
@@ -62,20 +72,18 @@ The configuration options are described in `config.txt`, which the installer cop

 ## Images

-The image path can be changed in the configuration file. The default path is `[EFI System Partition]\EFI\HackBGRT\splash.bmp`.
+If you only need one image, just edit `splash.bmp` to your needs.

-The installer copies and converts files whose `path` starts with `\EFI\HackBGRT\`. For example, to use a file named `my.jpg`, copy it in the installer folder (same folder as `setup.exe`) and set the image path in `config.txt` to `path=\EFI\HackBGFT\my.jpg`.
+Advanced users may edit the `config.txt` to define multiple images, in which case one is picked at random. The installer copies and converts the images. For example, to use a file named `my.jpg`, copy it in the installer folder (same folder as `setup.exe`) and set the image path in `config.txt` to `path=my.jpg` before running the installer.

 If you copy an image file to ESP manually, note that the image must be a 24-bit BMP file with a 54-byte header. That's a TrueColor BMP3 in Imagemagick, or 24-bit BMP/DIB in Microsoft Paint.

-Advanced users may edit the `config.txt` to define multiple images, in which case one is picked at random.
-
 ## Recovery

 If something breaks and you can't boot to Windows, you need to use the Windows installation disk (or recovery disk) to fix boot issues.

 ## Building

-* Compiler: GCC targeting w64-mingw32
+* Compiler: Clang
 * Compiler flags: see Makefile
 * Libraries: gnu-efi
--- a/config.txt
+++ b/config.txt
@@ -16,16 +16,14 @@ boot=MS
 #  - "keep" to keep the firmware logo. Also keeps coordinates by default.
 #  - "remove" to remove the BGRT. Makes x and y meaningless.
 #  - "black" to use only a black image. Makes x and y meaningless.
-#  - "path=..." to read a BMP file.
-#    * NOTE: For path=\EFI\HackBGRT\*, the installer will copy and convert the file if necessary.
-#    * NOTE: For other paths, make sure that the file is a 24-bit BMP file with a 54-byte header.
-#    * NOTE: The file must be on the EFI System Partition. Do not add a drive letter!
+#  - "path=file.bmp" to read an image file.
+#    * NOTE: The installer can copy and convert BMP, PNG, JPEG, GIF.
 # Examples:
 #  - image=remove
 #  - image=black
-#  - image= x=0 y=-200 path=\EFI\HackBGRT\topimage.bmp
-#  - image= n=1 o=90 path=\EFI\HackBGRT\sideways.bmp
-#  - image= n=50 y=999999 o=keep path=\EFI\HackBGRT\probable.bmp
+#  - image= x=0 y=-200 path=topimage.bmp
+#  - image= n=1 o=90 path=sideways.bmp
+#  - image= n=50 y=999999 o=keep path=probable.bmp
 # The above examples together would produce
 #  - 1/54 chance for the default OS logo
 #  - 1/54 chance for black screen
@@ -33,11 +31,16 @@ boot=MS
 #  - 1/54 chance for splash.bmp, centered, orientation set to 90 degrees
 #  - 50/54 chance for probable.bmp, at the bottom edge, explicitly default orientation
 # Default: just one image.
-image= y=-200 path=\EFI\HackBGRT\splash.bmp
+image= y=-200 path=splash.bmp

 # Preferred resolution. Use 0x0 for maximum and -1x-1 for original.
 resolution=0x0

+# Logging (0 for disabled, 1 for enabled).
+# When logging is enabled, setup.exe can show debug information about the current boot.
+# The log might occupy a few kilobytes of RAM.
+log=1
+
 # Debug mode (0 for disabled, 1 for enabled).
 # Shows debug information and prompts for keypress before booting.
 debug=0
--- a/1
+++ b/1
--- a/shim-signed/COPYRIGHT
+++ b/shim-signed/COPYRIGHT
@@ -0,0 +1,55 @@
+Format: http://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: shim
+Upstream-Contact: Peter Jones <pjones@redhat.com>
+Source: https://github.com/rhboot/shim
+
+Files: *
+Copyright: 2012 Red Hat, Inc
+	2009-2012 Intel Corporation
+License: BSD-2-Clause
+
+Files: debian/po/cs.po
+Copyright: 2018 Michal Simunek <michal.simunek@gmail.com>
+License: BSD-2-Clause
+
+Files: debian/po/de.po
+Copyright: 2017, 2018 Markus Hiereth <markus.hiereth@freenet.de>
+License: BSD-2-Clause
+
+Files: debian/po/fr.po
+Copyright: 2017, 2018 Alban Vidal <alban.vidal@zordhak.fr>
+License: BSD-2-Clause
+
+Files: debian/po/nl.po
+Copyright: 2017, 2018 Frans Spiesschaert <Frans.Spiesschaert@yucom.be>
+License: BSD-2-Clause
+
+Files: debian/po/pt.po
+Copyright: 2017, 2018 Rui Branco <ruipb@debianpt.org>
+License: BSD-2-Clause
+
+License: BSD-2-Clause
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ .
+ Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ .
+ Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the
+ distribution.
+ .
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ OF THE POSSIBILITY OF SUCH DAMAGE.
--- a/shim-signed/mmaa64.efi
+++ b/shim-signed/mmaa64.efi
--- a/shim-signed/mmia32.efi
+++ b/shim-signed/mmia32.efi
--- a/shim-signed/mmx64.efi
+++ b/shim-signed/mmx64.efi
--- a/shim-signed/shimaa64.efi
+++ b/shim-signed/shimaa64.efi
--- a/shim-signed/shimia32.efi
+++ b/shim-signed/shimia32.efi
--- a/shim-signed/shimx64.efi
+++ b/shim-signed/shimx64.efi
--- a/shim.md
+++ b/shim.md
@@ -0,0 +1,286 @@
+# Secure Boot and *shim*
+
+Secure Boot accepts only trusted files during boot. The *shim* boot loader is a tool which allows you to select which files to trust. HackBGRT installs *shim* for you, but you need to configure it with these instructions.
+
+On the first boot after installing HackBGRT, you will see an error message saying "Verification failed". You need to press a key to enter the setup tool (MOKManager) where you can choose to trust HackBGRT. After that, use arrow keys to navigate and *Enter* to continue as described below.
+
+## 1. Verification failed
+
+This is the start of *shim* configuration.
+
+```
+ERROR
+Verification failed: (0x1A) Security Violation
+----+
+| OK |
+----+
+```
+
+Select `OK`, *Enter*.
+
+```
+Shim UEFI key management
+Press any key to perform MOK management
+Booting in 5 seconds
+```
+
+Press a key quickly to enter *MOK management* or the *MOKManager* program.
+
+## 2. MOK management
+
+```
+Perform MOK management
+
+Continue to boot
+Enroll key from disk
+Enroll hash from disk
+```
+
+Select `Enroll hash from disk`, *Enter*. This is the safest option where you choose to trust only a specific version of HackBGRT.
+
+You can also choose to `Enroll key from disk`, which means that you choose to trust anything signed with the same certificate. How do you know if it's safe? You don't – that's why you should rather use the other option or build your own version of HackBGRT with your own certificate.
+
+## 3a. Enroll hash from disk
+
+```
+Select Binary
+
+The Selected Binary will have its hash Enrolled
+This means it will subsequently Boot with no prompting
+Remember to make sure it is a genuine binary before enrolling its hash
+
+----------------+
+| YOUR DISK NAME |
+----------------+
+```
+
+Select the disk, *Enter*.
+
+```
+---------------+
+|     EFI/      |
+|    loader/    |
+| vmlinuz-linux |
+---------------+
+```
+
+Select `EFI/`, *Enter*.
+
+```
+------------+
+|    ../     |
+|   Boot/    |
+| HackBGRT/  |
+| Microsoft/ |
+------------+
+```
+
+Select `HackBGRT/`, *Enter*.
+
+```
+-----------------+
+|       ../       |
+|   grubx64.efi   |
+|   loader.efi    |
+|    mmx64.efi    |
+| certificate.cer |
+|   splash.bmp    |
+|   config.txt    |
+-----------------+
+```
+
+Select `grubx64.efi`, *Enter*.
+
+```
+[Enroll MOK]
+
+------------+
+| View key 0 |
+|  Continue  |
+------------+
+```
+
+To verify the key contents, select `View key 0`, *Enter*.
+
+```
+SHA256 hash
+(some hexadecimal values)
+```
+
+Press *Enter* to continue.
+
+```
+[Enroll MOK]
+
+------------+
+| View key 0 |
+|  Continue  |
+------------+
+```
+
+Select `Continue`, *Enter*.
+
+```
+Enroll the key(s)?
+
+-----+
+| No  |
+| Yes |
+-----+
+```
+
+Select `Yes`, *Enter*.
+
+```
+Perform MOK management
+
+-----------------------+
+|        Reboot         |
+| Enroll key from disk  |
+| Enroll hash from disk |
+-----------------------+
+```
+
+Select `Reboot`, *Enter*.
+
+You are now ready to boot using HackBGRT.
+
+## 3b. Enroll key from disk
+
+```
+Select Key
+
+The selected key will be enrolled into the MOK database
+This means any binaries signed with it will be run without prompting
+Remember to make sure it is a genuine key before Enrolling it
+
+----------------+
+| YOUR DISK NAME |
+----------------+
+```
+
+Select the disk, *Enter*.
+
+```
+---------------+
+|     EFI/      |
+|    loader/    |
+| vmlinuz-linux |
+---------------+
+```
+
+Select `EFI/`, *Enter*.
+
+```
+------------+
+|    ../     |
+|   Boot/    |
+| HackBGRT/  |
+| Microsoft/ |
+------------+
+```
+
+Select `HackBGRT/`, *Enter*.
+
+```
+-----------------+
+|       ../       |
+|   grubx64.efi   |
+|   loader.efi    |
+|    mmx64.efi    |
+| certificate.cer |
+|   splash.bmp    |
+|   config.txt    |
+-----------------+
+```
+
+Select `certificate.cer`, *Enter*.
+
+```
+[Enroll MOK]
+
+------------+
+| View key 0 |
+|  Continue  |
+------------+
+```
+
+To verify the key contents, select `View key 0`, *Enter*.
+
+```
+[Extended Key Usage]
+OID: Code Signing
+
+[Serial Number]
+6B:24:52:E9:3B:84:41:73:B0:22:92:E8:BE:8E:38:85:
+
+[Issuer]
+CN=HackBGRT Secure Boot Signer, O=Metabolix
+
+[Subject]
+CN=HackBGRT Secure Boot Signer, O=Metabolix
+
+[Valid Not Before]
+Nov  9 13:43:56 2023 GMT
+
+[Valid Not After]
+Jan 19 03:14:07 2037 GMT
+
+[Fingerprint]
+79 8E 64 40 D1 D1 F4 53 30 8D
+A0 83 A4 77 FE 57 45 30 36 60
+```
+
+Press *Enter* to continue.
+
+```
+[Enroll MOK]
+
+------------+
+| View key 0 |
+|  Continue  |
+------------+
+```
+
+Select `Continue`, *Enter*.
+
+```
+Enroll the key(s)?
+
+-----+
+| No  |
+| Yes |
+-----+
+```
+
+Select `Yes`, *Enter*.
+
+```
+Perform MOK management
+
+-----------------------+
+|        Reboot         |
+| Enroll key from disk  |
+| Enroll hash from disk |
+-----------------------+
+```
+
+Select `Reboot`, *Enter*.
+
+You are now ready to boot using HackBGRT.
+
+## Tutorial: *shim* for dummies
+
+To install *shim* manually, follow these steps (assuming x64 architecture):
+
+1. Get *shim*, preferably *shim-signed*.
+2. Rename your boot loader to `grubx64.efi`.
+3. Copy `shimx64.efi` where your loader used to be.
+4. Copy `mmx64.efi` to the same folder.
+
+The *shim* boot process is as follows:
+
+1. Your computer starts `your-loader-name.efi`, which is now really *shim*.
+2. Next, *shim* tries to load `grubx64.efi`.
+3. If `grubx64.efi` is trusted, the boot process continues.
+4. Otherwise, *shim* offers to launch *MOKManager* `mmx64.efi`, and you can try again after that.
--- a/src/Efi.cs
+++ b/src/Efi.cs
@@ -55,6 +55,9 @@ public class Efi {
 		 * @return String representation of this object.
 		 */
 		public override string ToString() {
+			if (Data == null) {
+				return $"{Name} Guid={Guid} Attributes={Attributes} Data=null";
+			}
 			var hex = BitConverter.ToString(Data).Replace("-", " ");
 			var text = new string(Data.Select(c => 0x20 <= c && c <= 0x7f ? (char) c : ' ').ToArray());
 			return $"{Name} Guid={Guid} Attributes={Attributes} Text='{text}' Bytes='{hex}'";
@@ -90,12 +93,19 @@ public class Efi {
 			var pos = 6 + 2 * (Label.Length + 1);
 			var pathNodesEnd = pos + pathNodesLength;
 			DevicePathNodes = new List<DevicePathNode>();
+			Arguments = new byte[0];
 			while (pos + 4 <= pathNodesEnd) {
 				var len = BitConverter.ToUInt16(data, pos + 2);
 				if (len < 4 || pos + len > pathNodesEnd) {
 					return; // throw new Exception("Bad entry.");
 				}
-				DevicePathNodes.Add(new DevicePathNode(data.Skip(pos).Take(len).ToArray()));
+				var node = new DevicePathNode(data.Skip(pos).Take(len).ToArray());
+				DevicePathNodes.Add(node);
+				if (node.Type == 0x7f && node.SubType == 0xff) {
+					// End of entire device path.
+					// Apparently some firmwares produce paths with unused nodes at the end.
+					break;
+				}
 				pos += len;
 			}
 			Arguments = data.Skip(pathNodesEnd).ToArray();
@@ -136,8 +146,19 @@ public class Efi {
 		}
 	}

+	/**
+	 * GUID of the global EFI variables.
+	 */
 	public const string EFI_GLOBAL_GUID = "{8be4df61-93ca-11d2-aa0d-00e098032b8c}";

+	/**
+	 * GUID for HackBGRT EFI variables.
+	 */
+	public const string EFI_HACKBGRT_GUID = "{03c64761-075f-4dba-abfb-2ed89e18b236}";
+
+	/**
+	 * Directory containing EFI variables in Linux.
+	 */
 	public const string LinuxEfiDir = "/sys/firmware/efi/efivars";

 	/**
@@ -364,9 +385,10 @@ public class Efi {
 	 *
 	 * @param label Label of the boot entry.
 	 * @param fileName File name of the boot entry.
+	 * @param alwaysCopyFromMS If true, do not preserve any existing data.
 	 * @param dryRun Don't actually create the entry.
 	 */
-	public static void MakeAndEnableBootEntry(string label, string fileName, bool dryRun = false) {
+	public static void MakeAndEnableBootEntry(string label, string fileName, bool alwaysCopyFromMS, bool dryRun = false) {
 		Variable msEntry = null, ownEntry = null;
 		UInt16 msNum = 0, ownNum = 0;

@@ -389,10 +411,11 @@ public class Efi {
 		Setup.Log($"Read EFI variable: {bootOrder}");
 		Setup.Log($"Read EFI variable: {bootCurrent}");
 		var bootOrderInts = new List<UInt16>(BytesToUInt16s(bootOrder.Data));
-		foreach (var num in BytesToUInt16s(bootCurrent.Data).Concat(bootOrderInts).Concat(Enumerable.Range(0, 0xffff).Select(i => (UInt16) i))) {
+		foreach (var num in BytesToUInt16s(bootCurrent.Data).Concat(bootOrderInts).Concat(Enumerable.Range(0, 0xff).Select(i => (UInt16) i))) {
 			var entry = GetVariable(String.Format("Boot{0:X04}", num));
 			if (entry.Data == null) {
-				if (ownEntry == null) {
+				// Use only Boot0000 .. Boot00FF because some firmwares expect that.
+				if (ownEntry == null && num < 0x100) {
 					ownNum = num;
 					ownEntry = entry;
 				}
@@ -420,12 +443,28 @@ public class Efi {
 			throw new Exception("MakeBootEntry: Windows Boot Manager not found.");
 		} else {
 			Setup.Log($"Read EFI variable: {msEntry}");
+			Setup.Log($"Read EFI variable: {ownEntry}");
 			// Make a new boot entry using the MS entry as a starting point.
 			var entryData = new BootEntryData(msEntry.Data);
-			entryData.Arguments = Encoding.UTF8.GetBytes(label + "\0");
+			if (!alwaysCopyFromMS && ownEntry.Data != null) {
+				entryData = new BootEntryData(ownEntry.Data);
+				// Shim expects the arguments to be a filename or nothing.
+				// But BCDEdit expects some Microsoft-specific data.
+				// Modify the entry so that BCDEdit still recognises it
+				// but the data becomes a valid UCS-2 / UTF-16LE file name.
+				var str = new string(entryData.Arguments.Take(12).Select(c => (char) c).ToArray());
+				if (str == "WINDOWS\0\x01\0\0\0") {
+					entryData.Arguments[8] = (byte) 'X';
+				} else if (str != "WINDOWS\0\x58\0\0\0") {
+					// Not recognized. Clear the arguments.
+					entryData.Arguments = new byte[0];
+				}
+			} else {
+				entryData.Arguments = new byte[0];
+				entryData.Label = label;
+				entryData.FileName = fileName;
+			}
 			entryData.Attributes = 1; // LOAD_OPTION_ACTIVE
-			entryData.Label = label;
-			entryData.FileName = fileName;
 			ownEntry.Attributes = 7; // EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS
 			ownEntry.Data = entryData.ToBytes();
 			SetVariable(ownEntry, dryRun);
@@ -445,6 +484,49 @@ public class Efi {
 		}
 	}

+	/**
+	 * Log the boot entries.
+	 */
+	public static void LogBootEntries() {
+		try {
+			var bootOrder = GetVariable("BootOrder");
+			var bootCurrent = GetVariable("BootCurrent");
+			Setup.Log($"LogBootOrder: {bootOrder}");
+			Setup.Log($"LogBootOrder: {bootCurrent}");
+			var bootOrderInts = new List<UInt16>(BytesToUInt16s(bootOrder.Data));
+			// Windows can't enumerate EFI variables, and trying them all is too slow.
+			// BootOrder + BootCurrent + the first 0xff entries should be enough.
+			var seen = new HashSet<UInt16>();
+			foreach (var num in bootOrderInts.Concat(BytesToUInt16s(bootCurrent.Data)).Concat(Enumerable.Range(0, 0xff).Select(i => (UInt16) i))) {
+				if (seen.Contains(num)) {
+					continue;
+				}
+				seen.Add(num);
+				var entry = GetVariable(String.Format("Boot{0:X04}", num));
+				if (entry.Data != null) {
+					Setup.Log($"LogBootOrder: {entry}");
+				}
+			}
+		} catch (Exception e) {
+			Setup.Log($"LogBootOrder failed: {e.ToString()}");
+		}
+	}
+
+	/**
+	 * Retrieve HackBGRT log collected during boot.
+	 */
+	public static string GetHackBGRTLog() {
+		try {
+			var log = GetVariable("HackBGRTLog", EFI_HACKBGRT_GUID);
+			if (log.Data == null) {
+				return "(null)";
+			}
+			return new string(BytesToUInt16s(log.Data).Select(i => (char)i).ToArray());
+		} catch (Exception e) {
+			return $"Log not found: {e.ToString()}";
+		}
+	}
+
 	/**
 	 * Log the BGRT table (for debugging).
 	 */
@@ -456,14 +538,14 @@ public class Efi {
 			var ret = GetSystemFirmwareTable(acpiBE, bgrtLE, buf, size);
 			if (ret == size) {
 				var hex = BitConverter.ToString(buf).Replace("-", " ");
-				Setup.Log($"LogBGRT: {hex}");
+				Setup.Log($"LogBGRT: {size} bytes: {hex}");
 			} else if (ret == 0) {
 				Setup.Log($"LogBGRT: Win32Error {Marshal.GetLastWin32Error()}");
 			} else {
 				Setup.Log($"LogBGRT: Size problems: spec {0x38}, buf {size}, ret {ret}");
 			}
 		} catch (Exception e) {
-			Setup.Log($"LogBGRT: {e}");
+			Setup.Log($"LogBGRT failed: {e}");
 		}
 	}
 }
--- a/src/Setup.cs
+++ b/src/Setup.cs
@@ -10,6 +10,8 @@ using System.Diagnostics;
 using System.Security.Principal;
 using System.Text.RegularExpressions;
 using System.Runtime.CompilerServices;
+using System.Management;
+using Microsoft.Win32;

 [assembly: AssemblyInformationalVersionAttribute(GIT_DESCRIBE.data)]
 [assembly: AssemblyProductAttribute("HackBGRT")]
@@ -51,6 +53,7 @@ public class Setup {
 	public enum BootLoaderType {
 		None,
 		Own,
+		Shim,
 		Microsoft,
 		Other,
 	}
@@ -61,12 +64,14 @@ public class Setup {
 		"allow-secure-boot",
 		"allow-bitlocker",
 		"allow-bad-loader",
+		"skip-shim",
 		"enable-entry", "disable-entry",
 		"enable-bcdedit", "disable-bcdedit",
 		"enable-overwrite", "disable-overwrite",
 		"disable",
 		"uninstall",
 		"boot-to-fw",
+		"show-boot-log",
 	};

 	/** @var The target directory. */
@@ -94,6 +99,9 @@ public class Setup {
 	/** @var Run in batch mode? */
 	protected bool Batch;

+	/** @var Is the loader signed? */
+	protected bool LoaderIsSigned = false;
+
 	/**
 	 * Output a line.
 	 */
@@ -136,10 +144,9 @@ public class Setup {
 	 *
 	 * @param app Path to the application.
 	 * @param args The argument string.
-	 * @param nullOnFail If set, return null if the program exits with a code other than 0, even if there was some output.
-	 * @return The output, or null if the execution failed.
+	 * @return The output and exit code.
 	 */
-	public static string Execute(string app, string args, bool nullOnFail) {
+	public static (string Output, int ExitCode) Execute(string app, string args) {
 		Log($"Execute: {app} {args}");
 		try {
 			var info = new ProcessStartInfo(app, args);
@@ -149,13 +156,26 @@ public class Setup {
 			string output = p.StandardOutput.ReadToEnd();
 			p.WaitForExit();
 			Log($"Exit code: {p.ExitCode}, output:\n{output}\n\n");
-			return (nullOnFail && p.ExitCode != 0) ? null : output;
+			return (output, p.ExitCode);
 		} catch (Exception e) {
 			Log($"Execute failed: {e.ToString()}");
-			return null;
+			return (null, -1);
 		}
 	}

+	/**
+	 * Execute another process, return the output.
+	 *
+	 * @param app Path to the application.
+	 * @param args The argument string.
+	 * @param nullOnFail If set, return null if the program exits with a code other than 0, even if there was some output.
+	 * @return The output, or null if the execution failed.
+	 */
+	public static string Execute(string app, string args, bool nullOnFail) {
+		var result = Execute(app, args);
+		return (nullOnFail && result.ExitCode != 0) ? null : result.Output;
+	}
+
 	/**
 	 * Check for required privileges (access to ESP and EFI vars).
 	 *
@@ -204,6 +224,8 @@ public class Setup {
 			string tmp = System.Text.Encoding.ASCII.GetString(data);
 			if (tmp.IndexOf("HackBGRT") >= 0 || tmp.IndexOf("HackBgrt") >= 0) {
 				return BootLoaderType.Own;
+			} else if (tmp.IndexOf("UEFI shim") >= 0) {
+				return BootLoaderType.Shim;
 			} else if (tmp.IndexOf("Microsoft Corporation") >= 0) {
 				return BootLoaderType.Microsoft;
 			} else {
@@ -229,6 +251,8 @@ public class Setup {
 				0x0200 => "ia64",
 				0x8664 => "x64",
 				0xaa64 => "aa64",
+				0x01c2 => "arm",
+				0x01c4 => "arm",
 				_ => $"unknown-{peArch:x4}"
 			};
 		} catch {
@@ -307,10 +331,28 @@ public class Setup {

 	/**
 	 * Install files to ESP.
+	 *
+	 * @param skipShim Whether to skip installing shim.
 	 */
-	protected void InstallFiles() {
-		if (!File.Exists($"boot{EfiArch}.efi")) {
-			throw new SetupException($"Missing boot{EfiArch}.efi, {EfiArch} is not supported!");
+	protected void InstallFiles(bool skipShim) {
+		var loaderSource = Path.Combine("efi-signed", $"boot{EfiArch}.efi");
+		LoaderIsSigned = true;
+		if (!File.Exists(loaderSource)) {
+			loaderSource = Path.Combine("efi", $"boot{EfiArch}.efi");
+			LoaderIsSigned = false;
+			if (!File.Exists(loaderSource)) {
+				throw new SetupException($"Missing boot{EfiArch}.efi, {EfiArch} is not supported!");
+			}
+		}
+		var shimSource = Path.Combine("shim-signed", $"shim{EfiArch}.efi");
+		var mmSource = Path.Combine("shim-signed", $"mm{EfiArch}.efi");
+		if (!skipShim) {
+			if (!File.Exists(shimSource)) {
+				throw new SetupException($"Missing shim ({shimSource}), can't install shim for {EfiArch}!");
+			}
+			if (!File.Exists(mmSource)) {
+				throw new SetupException($"Missing MokManager ({mmSource}), can't install shim for {EfiArch}!");
+			}
 		}
 		try {
 			if (!Directory.Exists(InstallPath)) {
@@ -324,23 +366,76 @@ public class Setup {
 		var lines = File.ReadAllLines("config.txt");
 		Log($"config.txt:\n{String.Join("\n", lines)}");
 		foreach (var line in lines.Where(s => s.StartsWith("image="))) {
-			var delim = "path=\\EFI\\HackBGRT\\";
+			var delim = "path=";
 			var i = line.IndexOf(delim);
 			if (i > 0) {
-				InstallImageFile(line.Substring(i + delim.Length));
+				var dir = "\\EFI\\HackBGRT\\";
+				if (line.Substring(i + delim.Length).StartsWith(dir)) {
+					InstallImageFile(line.Substring(i + delim.Length + dir.Length));
+				}
+				if (!line.Substring(i + delim.Length).StartsWith("\\")) {
+					InstallImageFile(line.Substring(i + delim.Length));
+				}
 			}
 		}
-		InstallFile($"boot{EfiArch}.efi", "loader.efi");
+		var loaderDest = "loader.efi";
+		if (!skipShim) {
+			InstallFile(shimSource, loaderDest);
+			InstallFile(mmSource, $"mm{EfiArch}.efi");
+			loaderDest = $"grub{EfiArch}.efi";
+		}
+		InstallFile(loaderSource, loaderDest);
+		InstallFile(loaderSource, "\u4957\u444e\u574f\u0053\u0058"); // bytes "WINDOWS\0X\0" as UTF-16
+		if (LoaderIsSigned) {
+			InstallFile("certificate.cer");
+		}
 		WriteLine($"HackBGRT has been copied to {InstallPath}.");
+
+		var enrollHashPath = $"EFI\\HackBGRT\\{loaderDest}";
+		var enrollKeyPath = "EFI\\HackBGRT\\certificate.cer";
+		if (skipShim) {
+			if (LoaderIsSigned) {
+				WriteLine($"Remember to enroll {enrollKeyPath} in your firmware!");
+			} else {
+				WriteLine("This HackBGRT build is not signed. You may need to disable Secure Boot.");
+			}
+		} else {
+			WriteLine($"On first boot, select 'Enroll hash from disk' and enroll {enrollHashPath}.");
+			if (LoaderIsSigned) {
+				WriteLine($"Alternatively, select 'Enroll key from disk' and enroll {enrollKeyPath}.");
+			}
+		}
 	}

 	/**
 	 * Enable HackBGRT with bcdedit.
 	 */
 	protected void EnableBCDEdit() {
+		if (DryRun) {
+			WriteLine("Dry run, skip enabling with BCDEdit.");
+			return;
+		}
+		var bcdeditEnum = Execute("bcdedit", "/enum firmware");
+		if (bcdeditEnum.ExitCode != 0) {
+			WriteLine("BCDEdit is not working. Fix it or try another method.");
+			if (bcdeditEnum.Output != null) {
+				var lastLine = bcdeditEnum.Output.Split("\n".ToCharArray()).Last();
+				WriteLine($"BCDEdit output: {lastLine}");
+				WriteLine("Disable antivirus, check your hard disk, or search 'how to fix 0x800703EE'.");
+			}
+			throw new SetupException("Failed to enable HackBGRT with BCDEdit!");
+		}
 		try {
 			var re = new Regex("[{][0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}[}]");
-			var guid = re.Match(Execute("bcdedit", "/copy {bootmgr} /d HackBGRT", true)).Value;
+			var bcdCopy = Execute("bcdedit", "/copy {bootmgr} /d HackBGRT").Output;
+			if (bcdCopy == null) {
+				throw new SetupException("Failed to create a new BCDEdit entry for HackBGRT!");
+			}
+			var match = re.Match(bcdCopy);
+			if (!match.Success) {
+				throw new SetupException("Failed to get a GUID for the new BCDEdit entry for HackBGRT!");
+			}
+			var guid = match.Value;
 			Execute("bcdedit", $"/set {guid} device partition={Esp.Location}", true);
 			Execute("bcdedit", $"/set {guid} path \\EFI\\HackBGRT\\loader.efi", true);
 			foreach (var arg in new string[] { "locale", "inherit", "default", "resumeobject", "displayorder", "toolsdisplayorder", "timeout" }) {
@@ -348,6 +443,12 @@ public class Setup {
 			}
 			var fwbootmgr = "{fwbootmgr}";
 			Execute("bcdedit", $"/set {fwbootmgr} displayorder {guid} /addfirst", true);
+			WriteLine("Enabled NVRAM entry for HackBGRT with BCDEdit.");
+			// Verify that the entry was created.
+			Execute("bcdedit", "/enum firmware", true);
+			Efi.MakeAndEnableBootEntry("HackBGRT", "\\EFI\\HackBGRT\\loader.efi", false, DryRun);
+			Execute("bcdedit", $"/enum {guid}", true);
+			Efi.LogBootEntries();
 		} catch (Exception e) {
 			Log($"EnableBCDEdit failed: {e.ToString()}");
 			throw new SetupException("Failed to enable HackBGRT with BCDEdit!");
@@ -372,14 +473,18 @@ public class Setup {
 			} else if (entry.IndexOf("HackBGRT") >= 0) {
 				found = true;
 				Log($"Disabling HackBGRT entry {guid}.");
-				if (Execute("bcdedit", $"/delete {guid}", true) == null) {
+				if (!DryRun && Execute("bcdedit", $"/delete {guid}", true) == null) {
 					Log($"DisableBCDEdit failed to delete {guid}.");
+				} else {
+					disabled = true;
 				}
-				disabled = true;
 			}
 		}
-		if (found && !disabled) {
-			throw new SetupException("Failed to disable HackBGRT with BCDEdit!");
+		if (found) {
+			if (!disabled) {
+				throw new SetupException("Failed to disable HackBGRT with BCDEdit!");
+			}
+			WriteLine("Disabled NVRAM entry for HackBGRT with BCDEdit.");
 		}
 	}

@@ -387,8 +492,11 @@ public class Setup {
 	 * Enable HackBGRT boot entry.
 	 */
 	protected void EnableEntry() {
-		Efi.MakeAndEnableBootEntry("HackBGRT", "\\EFI\\HackBGRT\\loader.efi", DryRun);
+		Efi.MakeAndEnableBootEntry("HackBGRT", "\\EFI\\HackBGRT\\loader.efi", true, DryRun);
 		WriteLine("Enabled NVRAM entry for HackBGRT.");
+		// Verify that the entry was created.
+		Efi.LogBootEntries();
+		Execute("bcdedit", "/enum firmware", true);
 	}

 	/**
@@ -405,7 +513,6 @@ public class Setup {
 	protected void OverwriteMsLoader() {
 		var ms = Esp.MsLoaderPath;
 		var backup = BackupLoaderPath;
-		var own = Path.Combine(InstallPath, "loader.efi");

 		if (DetectLoader(ms) == BootLoaderType.Microsoft) {
 			InstallFile(ms, backup, false);
@@ -414,8 +521,13 @@ public class Setup {
 			// Duplicate check, but better to be sure...
 			throw new SetupException("Missing MS boot loader backup!");
 		}
+		var msDir = Path.GetDirectoryName(ms);
+		var msGrub = Path.Combine(msDir, $"grub{EfiArch}.efi");
+		var msMm = Path.Combine(msDir, $"mm{EfiArch}.efi");
 		try {
-			InstallFile(own, ms, false);
+			InstallFile(Path.Combine(InstallPath, "loader.efi"), ms, false);
+			InstallFile(Path.Combine(InstallPath, $"grub{EfiArch}.efi"), msGrub, false);
+			InstallFile(Path.Combine(InstallPath, $"mm{EfiArch}.efi"), msMm, false);
 		} catch (SetupException e) {
 			WriteLine(e.Message);
 			if (DetectLoader(ms) != BootLoaderType.Microsoft) {
@@ -434,7 +546,7 @@ public class Setup {
 	 */
 	protected void RestoreMsLoader() {
 		var ms = Esp.MsLoaderPath;
-		if (DetectLoader(ms) == BootLoaderType.Own) {
+		if (DetectLoader(ms) == BootLoaderType.Own || DetectLoader(ms) == BootLoaderType.Shim) {
 			WriteLine("Disabling an old version of HackBGRT.");
 			InstallFile(BackupLoaderPath, ms, false);
 			WriteLine($"{ms} has been restored.");
@@ -450,7 +562,7 @@ public class Setup {
 	 */
 	protected void VerifyLoaderConfig() {
 		var lines = File.ReadAllLines("config.txt");
-		var loader = lines.Where(s => s.StartsWith("boot=")).Select(s => s.Substring(5)).Prepend("").Last();
+		var loader = lines.Where(s => s.StartsWith("boot=")).Select(s => s.Substring(5)).LastOrDefault();
 		if (loader == null) {
 			throw new SetupException("config.txt does not contain a boot=... line!");
 		}
@@ -514,7 +626,9 @@ public class Setup {
 	protected void Uninstall() {
 		Disable();
 		try {
-			Directory.Delete(InstallPath, true);
+			if (Directory.Exists(InstallPath)) {
+				Directory.Delete(InstallPath, true);
+			}
 			WriteLine($"HackBGRT has been removed from {InstallPath}.");
 		} catch (Exception e) {
 			Log($"Uninstall failed: {e.ToString()}");
@@ -538,6 +652,9 @@ public class Setup {
 				WriteLine("Secure Boot status could not be determined.");
 			}
 			WriteLine("It's very important to disable Secure Boot before installing.");
+			if (LoaderIsSigned) {
+				WriteLine("Alternatively, you can enroll the certificate.cer in your firmware.");
+			}
 			WriteLine("Otherwise your machine may become unbootable.");
 			if (Batch) {
 				if (allowSecureBoot) {
@@ -573,8 +690,8 @@ public class Setup {
 			WriteLine("BitLocker status could not be determined.");
 			return;
 		}
-		var reOn = new Regex(@"Conversion Status:\s*(Encr|Fully Encr)|Protection Status:\s*Protection On");
-		var reOff = new Regex(@"Conversion Status:\s*(Fully Decrypted)|Protection Status:\s*Protection Off");
+		var reOn = new Regex(@"Conversion Status:\s*.*Encr|AES");
+		var reOff = new Regex(@"Conversion Status:\s*(Fully Decrypted)|\s0[.,]0\s*%");
 		var isOn = reOn.Match(output).Success;
 		var isOff = reOff.Match(output).Success;
 		if (!isOn && isOff) {
@@ -644,8 +761,13 @@ public class Setup {
 	 * @param arch The architecture.
 	 */
 	protected void SetArch(string arch) {
-		var detectedArch = DetectArchFromOS();
-		if (arch == "") {
+		var detectedArch = Environment.Is64BitOperatingSystem ? "x64" : "ia32";
+		try {
+			detectedArch = DetectArchFromOS();
+		} catch {
+			WriteLine($"Failed to detect OS architecture, assuming {detectedArch}.");
+		}
+		if (arch == "" || arch == null) {
 			EfiArch = detectedArch;
 			WriteLine($"Your OS uses arch={EfiArch}. This will be checked again during installation.");
 		} else {
@@ -674,6 +796,40 @@ public class Setup {
 		}
 	}

+	/**
+	 * Log the boot time.
+	 *
+	 * @return The boot time, or null if it couldn't be determined.
+	 */
+	protected DateTime? GetBootTime() {
+		try {
+			var query = new ObjectQuery("SELECT LastBootUpTime FROM Win32_OperatingSystem WHERE Primary='true'");
+			foreach (var m in new ManagementObjectSearcher(query).Get()) {
+				return ManagementDateTimeConverter.ToDateTime(m["LastBootUpTime"].ToString());
+			}
+		} catch (Exception e) {
+			Log($"GetBootTime failed: {e.ToString()}");
+		}
+		return null;
+	}
+
+	/**
+	 * Check if Hiberboot is enabled.
+	 *
+	 * @return True, if Hiberboot is enabled.
+	 */
+	protected bool IsHiberbootEnabled() {
+		try {
+			return (int) Registry.GetValue(
+				"HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Power",
+				"HiberbootEnabled",
+				0
+			) != 0;
+		} catch {
+			return false;
+		}
+	}
+
 	/**
 	 * Ask for user's choice and install/uninstall.
 	 */
@@ -682,19 +838,14 @@ public class Setup {
 		WriteLine("Choose action (press a key):");
 		WriteLine(" I = install");
 		WriteLine("     - creates a new EFI boot entry for HackBGRT");
-		WriteLine("     - sometimes needs to be enabled in firmware settings");
-		WriteLine("     - should fall back to MS boot loader if HackBGRT fails");
 		WriteLine(" J = install (alternative)");
-		WriteLine("     - creates a new EFI boot entry with an alternative method (BCDEdit)");
-		WriteLine("     - always sets HackBGRT as the first boot option");
-		WriteLine("     - sometimes shows up as \"Windows Boot Manager\"");
-		WriteLine("     - should fall back to MS boot loader if HackBGRT fails");
+		WriteLine("     - creates a new EFI boot entry with an alternative method");
+		WriteLine("     - try this if the first option doesn't work");
 		WriteLine(" O = install (legacy)");
-		WriteLine("     - overwrites the MS boot loader");
-		WriteLine("     - may require re-install after Windows updates");
-		WriteLine("     - could brick your system if configured incorrectly");
+		WriteLine("     - overwrites the MS boot loader; gets removed by Windows updates");
+		WriteLine("     - use as last resort; may brick your system if configured incorrectly");
 		WriteLine(" F = install files only");
-		WriteLine("     - needs to be enabled somehow");
+		WriteLine("     - ok for updating config, doesn't touch boot entries");
 		WriteLine(" D = disable");
 		WriteLine("     - removes created entries, restores MS boot loader");
 		WriteLine(" R = remove completely");
@@ -702,28 +853,31 @@ public class Setup {
 		WriteLine(" B = boot to UEFI setup");
 		WriteLine("     - lets you disable Secure Boot");
 		WriteLine("     - lets you move HackBGRT before Windows in boot order");
+		WriteLine(" L = show boot log (what HackBGRT did during boot)");
 		WriteLine(" C = cancel");

 		var k = Console.ReadKey().Key;
 		Log($"User input: {k}");
 		WriteLine();
-		if (k == ConsoleKey.I || k == ConsoleKey.O || k == ConsoleKey.F) {
+		if (k == ConsoleKey.I || k == ConsoleKey.J || k == ConsoleKey.O || k == ConsoleKey.F) {
 			Configure();
 		}
 		if (k == ConsoleKey.I) {
-			RunPrivilegedActions(new string[] { "install", "enable-entry" });
+			RunPrivilegedActions(new string[] { "disable", "install", "enable-bcdedit" });
 		} else if (k == ConsoleKey.J) {
-			RunPrivilegedActions(new string[] { "install", "enable-bcdedit" });
+			RunPrivilegedActions(new string[] { "disable", "install", "enable-entry" });
 		} else if (k == ConsoleKey.O) {
-			RunPrivilegedActions(new string[] { "install", "enable-overwrite" });
+			RunPrivilegedActions(new string[] { "disable", "install", "enable-overwrite" });
 		} else if (k == ConsoleKey.F) {
-			RunPrivilegedActions(new string[] { "install" });
+			RunPrivilegedActions(new string[] { "disable-overwrite", "install" });
 		} else if (k == ConsoleKey.D) {
 			RunPrivilegedActions(new string[] { "disable" });
 		} else if (k == ConsoleKey.R) {
 			RunPrivilegedActions(new string[] { "uninstall" });
 		} else if (k == ConsoleKey.B) {
 			RunPrivilegedActions(new string[] { "boot-to-fw" });
+		} else if (k == ConsoleKey.L) {
+			RunPrivilegedActions(new string[] { "show-boot-log" });
 		} else if (k == ConsoleKey.C) {
 			throw new ExitSetup(1);
 		} else {
@@ -757,10 +911,24 @@ public class Setup {

 		InitEspPath();
 		InitEspInfo();
+		var bootLog = $"\n--- BOOT LOG START ---\n{Efi.GetHackBGRTLog()}\n--- BOOT LOG END ---";
+		Setup.Log(bootLog);
 		Efi.LogBGRT();
+		Efi.LogBootEntries();
+		if (GetBootTime() is DateTime bootTime) {
+			var configTime = new[] { File.GetCreationTime("config.txt"), File.GetLastWriteTime("config.txt") }.Max();
+			Log($"Boot time = {bootTime}, config.txt changed = {configTime}");
+			if (configTime > bootTime) {
+				WriteLine($"Windows was booted at {bootTime}. Remember to reboot after installing!");
+			}
+		}
+		if (IsHiberbootEnabled()) {
+			WriteLine("You may have to disable Fast Startup (Hiberboot) to reboot properly.");
+		}
 		bool allowSecureBoot = false;
 		bool allowBitLocker = false;
 		bool allowBadLoader = false;
+		bool skipShim = false;
 		Action<Action> verify = (Action revert) => {
 			try {
 				VerifyLoaderConfig();
@@ -776,7 +944,9 @@ public class Setup {
 			}
 		};
 		Action<Action, Action> enable = (Action enable, Action revert) => {
-			HandleSecureBoot(allowSecureBoot);
+			if (skipShim) {
+				HandleSecureBoot(allowSecureBoot);
+			}
 			HandleBitLocker(allowBitLocker);
 			enable();
 			verify(revert);
@@ -784,13 +954,15 @@ public class Setup {
 		foreach (var arg in actions) {
 			Log($"Running action '{arg}'.");
 			if (arg == "install") {
-				InstallFiles();
+				InstallFiles(skipShim);
 			} else if (arg == "allow-secure-boot") {
 				allowSecureBoot = true;
 			} else if (arg == "allow-bitlocker") {
 				allowBitLocker = true;
 			} else if (arg == "allow-bad-loader") {
 				allowBadLoader = true;
+			} else if (arg == "skip-shim") {
+				skipShim = true;
 			} else if (arg == "enable-entry") {
 				enable(() => EnableEntry(), () => DisableEntry());
 			} else if (arg == "disable-entry") {
@@ -809,6 +981,8 @@ public class Setup {
 				Uninstall();
 			} else if (arg == "boot-to-fw") {
 				BootToFW();
+			} else if (arg == "show-boot-log") {
+				WriteLine(bootLog);
 			} else {
 				throw new SetupException($"Invalid action: '{arg}'!");
 			}
@@ -839,7 +1013,7 @@ public class Setup {
 		Batch = args.Contains("batch");
 		ForwardArguments = String.Join(" ", args.Where(s => s == "dry-run" || s == "batch" || s.StartsWith("arch=")));
 		try {
-			SetArch(args.Prepend("arch=").Last(s => s.StartsWith("arch=")).Substring(5));
+			SetArch(args.Where(s => s.StartsWith("arch=")).Select(s => s.Substring(5)).LastOrDefault());
 			if (args.Contains("is-elevated") && !HasPrivileges() && !DryRun) {
 				WriteLine("This installer needs to be run as administrator!");
 				return 1;
@@ -867,14 +1041,20 @@ public class Setup {
 			WriteLine();
 			WriteLine($"Unexpected error: {e.Message}");
 			Log(e.ToString());
-			WriteLine("If this is the most current release, please report this bug.");
+			if (e is MissingMemberException || e is TypeLoadException) {
+				WriteLine("This installer requires a recent version of .Net Framework.");
+				WriteLine("Use Windows Update or download manually:");
+				WriteLine("https://dotnet.microsoft.com/en-us/download/dotnet-framework");
+			} else {
+				WriteLine("If this is the most current release, please report this bug.");
+			}
 			return 1;
 		} finally {
 			if (DryRun) {
 				WriteLine("This was a dry run, your system was not actually modified.");
 			}
 			if (!Batch) {
-				WriteLine("If you need to report a bug, please include the setup.log file.");
+				WriteLine("If you need to report a bug,\n - run this setup again with menu option L (show-boot-log)\n - then include the setup.log file with your report.");
 				WriteLine("Press any key to quit.");
 				Console.ReadKey();
 			}
--- a/src/config.c
+++ b/src/config.c
@@ -1,14 +1,12 @@
 #include "config.h"
 #include "util.h"

-#include <efilib.h>
-
-BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, const CHAR16* path) {
+BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE base_dir, const CHAR16* path) {
 	void* data = 0;
 	UINTN data_bytes = 0;
-	data = LoadFileWithPadding(root_dir, path, &data_bytes, 4);
+	data = LoadFileWithPadding(base_dir, path, &data_bytes, 4);
 	if (!data) {
-		Print(L"HackBGRT: Failed to load configuration (%s)!\n", path);
+		Log(1, L"Failed to load configuration (%s)!\n", path);
 		return FALSE;
 	}
 	CHAR16* str;
@@ -21,7 +19,7 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 		// UTF-8 -> UCS-2
 		EFI_STATUS e = BS->AllocatePool(EfiBootServicesData, data_bytes * 2 + 2, (void**)&str);
 		if (EFI_ERROR(e)) {
-			FreePool(data);
+			BS->FreePool(data);
 			return FALSE;
 		}
 		UINT8* str0 = data;
@@ -51,7 +49,7 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 			}
 		}
 		str[str_len] = 0;
-		FreePool(data);
+		BS->FreePool(data);
 	}

 	for (int i = 0; i < str_len;) {
@@ -63,7 +61,7 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 			str[j] = 0;
 			++j;
 		}
-		ReadConfigLine(config, root_dir, &str[i]);
+		ReadConfigLine(config, base_dir, &str[i]);
 		i = j;
 	}
 	// NOTICE: string is not freed, because paths are not copied.
@@ -72,12 +70,10 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,

 static void SetBMPWithRandom(struct HackBGRT_config* config, int weight, enum HackBGRT_action action, int x, int y, int o, const CHAR16* path) {
 	config->image_weight_sum += weight;
-	UINT32 random = Random();
-	UINT32 limit = 0xfffffffful / config->image_weight_sum * weight;
-	if (config->debug) {
-		Print(L"HackBGRT: weight %d, action %d, x %d, y %d, o %d, path %s, random = %08x, limit = %08x\n", weight, action, x, y, o, path, random, limit);
-	}
-	if (!config->image_weight_sum || random <= limit) {
+	UINT32 random = (((UINT64) Random() & 0xffffffff) * config->image_weight_sum) >> 32;
+	UINT32 limit = ((UINT64) 0xffffffff * weight) >> 32;
+	Log(config->debug, L"%s n=%d, action=%d, x=%d, y=%d, o=%d, path=%s, rand=%x/%x\n", random <= limit ? L"Using" : L"Skipping", weight, action, x, y, o, path, random, limit);
+	if (random <= limit) {
 		config->action = action;
 		config->image_path = path;
 		config->orientation = o;
@@ -112,7 +108,7 @@ static void ReadConfigImage(struct HackBGRT_config* config, const CHAR16* line)
 	} else if (StrStr(line, L"keep")) {
 		action = HackBGRT_KEEP;
 	} else {
-		Print(L"HackBGRT: Invalid image line: %s\n", line);
+		Log(1, L"Invalid image line: %s\n", line);
 		return;
 	}
 	int weight = n && (!f || n < f) ? Atoi(n) : 1;
@@ -129,11 +125,11 @@ static void ReadConfigResolution(struct HackBGRT_config* config, const CHAR16* l
 		config->resolution_x = *x == '-' ? -(int)Atoi(x+1) : (int)Atoi(x);
 		config->resolution_y = *y == '-' ? -(int)Atoi(y+1) : (int)Atoi(y);
 	} else {
-		Print(L"HackBGRT: Invalid resolution line: %s\n", line);
+		Log(1, L"Invalid resolution line: %s\n", line);
 	}
 }

-void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, const CHAR16* line) {
+void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE base_dir, const CHAR16* line) {
 	line = TrimLeft(line);
 	if (line[0] == L'#' || line[0] == 0) {
 		return;
@@ -143,6 +139,10 @@ void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, co
 		config->debug = (StrCmp(line, L"debug=1") == 0);
 		return;
 	}
+	if (StrnCmp(line, L"log=", 4) == 0) {
+		config->log = (StrCmp(line, L"log=1") == 0);
+		return;
+	}
 	if (StrnCmp(line, L"image=", 6) == 0) {
 		ReadConfigImage(config, line + 6);
 		return;
@@ -152,12 +152,12 @@ void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, co
 		return;
 	}
 	if (StrnCmp(line, L"config=", 7) == 0) {
-		ReadConfigFile(config, root_dir, line + 7);
+		ReadConfigFile(config, base_dir, line + 7);
 		return;
 	}
 	if (StrnCmp(line, L"resolution=", 11) == 0) {
 		ReadConfigResolution(config, line + 11);
 		return;
 	}
-	Print(L"Unknown configuration directive: %s\n", line);
+	Log(1, L"Unknown configuration directive: %s\n", line);
 }
--- a/src/config.h
+++ b/src/config.h
@@ -1,6 +1,6 @@
 #pragma once

-#include <efi.h>
+#include "efi.h"

 /**
 * Possible actions to perform on the BGRT.
@@ -14,14 +14,14 @@ enum HackBGRT_action {
 * @see struct HackBGRT_config
 */
 enum HackBGRT_coordinate {
-	HackBGRT_coord_keep = -1000000001
+	HackBGRT_coord_keep = -1000001
 };

 /**
 * The configuration.
 */
 struct HackBGRT_config {
-	int debug;
+	int debug, log;
 	enum HackBGRT_action action;
 	const CHAR16* image_path;
 	int image_x;
@@ -39,17 +39,17 @@ struct HackBGRT_config {
 * Read a configuration parameter. (May recursively read config files.)
 *
 * @param config The configuration to modify.
- * @param root_dir The root directory, in case the parameter contains an include.
+ * @param base_dir The base directory, in case the parameter contains an include.
 * @param line The configuration line to parse.
 */
-extern void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, const CHAR16* line);
+extern void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE base_dir, const CHAR16* line);

 /**
 * Read a configuration file. (May recursively read more files.)
 *
 * @param config The configuration to modify.
- * @param root_dir The root directory.
+ * @param base_dir The base directory.
 * @param path The path to the file.
 * @return FALSE, if the file couldn't be read, TRUE otherwise.
 */
-extern BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, const CHAR16* path);
+extern BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE base_dir, const CHAR16* path);
--- a/src/efi.c
+++ b/src/efi.c
@@ -0,0 +1,159 @@
+#include "efi.h"
+#include "util.h"
+
+// New implementations of some functions in gnu-efi.
+// These functions are designed to avoid other gnu-efi calls.
+
+EFI_STATUS LibLocateProtocol(IN EFI_GUID *ProtocolGuid, OUT VOID **Interface) {
+	EFI_HANDLE buffer[256];
+	UINTN size = sizeof(buffer);
+	if (!EFI_ERROR(BS->LocateHandle(ByProtocol, ProtocolGuid, NULL, &size, buffer))) {
+		for (int i = 0; i < size / sizeof(EFI_HANDLE); ++i) {
+			if (!EFI_ERROR(BS->HandleProtocol(buffer[i], ProtocolGuid, Interface))) {
+				return EFI_SUCCESS;
+			}
+		}
+	}
+	return EFI_NOT_FOUND;
+}
+
+EFI_DEVICE_PATH *FileDevicePath(IN EFI_HANDLE Device OPTIONAL, IN CHAR16 *FileName) {
+	EFI_DEVICE_PATH *old_path = 0;
+	if (!Device || EFI_ERROR(BS->HandleProtocol(Device, TmpGuidPtr((EFI_GUID) EFI_DEVICE_PATH_PROTOCOL_GUID), (void**)&old_path))) {
+		static EFI_DEVICE_PATH end_path = {END_DEVICE_PATH_TYPE, END_ENTIRE_DEVICE_PATH_SUBTYPE, {sizeof(end_path), 0}};
+		old_path = &end_path;
+	}
+	UINTN old_path_size = 0, instances = 0;
+	for (EFI_DEVICE_PATH *p0 = old_path;; p0 = NextDevicePathNode(p0)) {
+		old_path_size += DevicePathNodeLength(p0);
+		if (IsDevicePathEndType(p0)) {
+			instances += 1;
+		}
+		if (IsDevicePathEnd(p0)) {
+			break;
+		}
+	}
+
+	UINTN size_str = (StrLen(FileName) + 1) * sizeof(*FileName);
+	UINTN size_fdp = SIZE_OF_FILEPATH_DEVICE_PATH + size_str;
+
+	EFI_DEVICE_PATH *new_path;
+	if (EFI_ERROR(BS->AllocatePool(EfiBootServicesData, old_path_size + instances * size_fdp, (void**)&new_path))) {
+		return 0;
+	}
+
+	EFI_DEVICE_PATH *p1 = new_path;
+	for (EFI_DEVICE_PATH *p0 = old_path;; p0 = NextDevicePathNode(p0)) {
+		if (IsDevicePathEndType(p0)) {
+			*p1 = (EFI_DEVICE_PATH) {
+				.Type = MEDIA_DEVICE_PATH,
+				.SubType = MEDIA_FILEPATH_DP,
+				.Length = {size_fdp, size_fdp >> 8},
+			};
+			FILEPATH_DEVICE_PATH *f = (FILEPATH_DEVICE_PATH *) p1;
+			BS->CopyMem(f->PathName, FileName, size_str);
+			p1 = NextDevicePathNode(p1);
+		}
+		BS->CopyMem(p1, p0, DevicePathNodeLength(p0));
+		if (IsDevicePathEnd(p0)) {
+			break;
+		}
+		p1 = NextDevicePathNode(p1);
+	}
+
+	return new_path;
+}
+
+INTN CompareMem(IN CONST VOID *Dest, IN CONST VOID *Src, IN UINTN len) {
+	CONST UINT8 *d = Dest, *s = Src;
+	for (UINTN i = 0; i < len; ++i) {
+		if (d[i] != s[i]) {
+			return d[i] - s[i];
+		}
+	}
+	return 0;
+}
+
+void StrnCat(IN CHAR16* dest, IN CONST CHAR16* src, UINTN len) {
+	CHAR16* d = dest;
+	while (*d) {
+		++d;
+	}
+	while (len-- && *src) {
+		*d++ = *src++;
+	}
+	*d = 0;
+}
+
+UINTN StrLen(IN CONST CHAR16* s) {
+	UINTN i = 0;
+	while (*s++) {
+		++i;
+	}
+	return i;
+}
+
+INTN StriCmp(IN CONST CHAR16* s1, IN CONST CHAR16* s2) {
+	while (*s1 && *s2) {
+		CHAR16 c1 = *s1++, c2 = *s2++;
+		if (c1 >= 'A' && c1 <= 'Z') {
+			c1 += 'a' - 'A';
+		}
+		if (c2 >= 'A' && c2 <= 'Z') {
+			c2 += 'a' - 'A';
+		}
+		if (c1 != c2) {
+			return c1 - c2;
+		}
+	}
+	return *s1 - *s2;
+}
+
+INTN StrnCmp(IN CONST CHAR16* s1, IN CONST CHAR16* s2, UINTN len) {
+	while (*s1 && *s2 && len--) {
+		CHAR16 c1 = *s1++, c2 = *s2++;
+		if (c1 >= 'A' && c1 <= 'Z') {
+			c1 += 'a' - 'A';
+		}
+		if (c2 >= 'A' && c2 <= 'Z') {
+			c2 += 'a' - 'A';
+		}
+		if (c1 != c2) {
+			return c1 - c2;
+		}
+	}
+	return len ? *s1 - *s2 : 0;
+}
+
+INTN StrCmp(IN CONST CHAR16* s1, IN CONST CHAR16* s2) {
+	while (*s1 && *s2) {
+		if (*s1 != *s2) {
+			return *s1 - *s2;
+		}
+		++s1, ++s2;
+	}
+	return *s1 - *s2;
+}
+
+UINTN Atoi(IN CONST CHAR16* s) {
+	UINTN n = 0;
+	while (*s >= '0' && *s <= '9') {
+		n = n * 10 + *s++ - '0';
+	}
+	return n;
+}
+
+void *memset(void *s, int c, __SIZE_TYPE__ n) {
+	unsigned char *p = s;
+	while (n--)
+		*p++ = c;
+	return s;
+}
+
+void *memcpy(void *dest, const void *src, __SIZE_TYPE__ n) {
+	const unsigned char *q = src;
+	unsigned char *p = dest;
+	while (n--)
+		*p++ = *q++;
+	return dest;
+}
--- a/src/efi.h
+++ b/src/efi.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <stdint.h>
+#include <efi.h>
+#include <efilib.h>
--- a/src/main.c
+++ b/src/main.c
@@ -1,25 +1,27 @@
-#include <efi.h>
-#include <efilib.h>
-
+#include "efi.h"
 #include "types.h"
 #include "config.h"
 #include "util.h"

 /**
- * The Print function signature.
+ * The version.
 */
-typedef UINTN print_t(IN CONST CHAR16 *fmt, ...);
+#ifdef GIT_DESCRIBE_W
+	const CHAR16 version[] = GIT_DESCRIBE_W;
+#else
+	const CHAR16 version[] = L"unknown; not an official release?";
+#endif

-/**
- * The function for debug printing; either Print or NullPrint.
- */
-print_t* Debug = NullPrint;
+EFI_SYSTEM_TABLE *ST;
+EFI_BOOT_SERVICES *BS;
+EFI_RUNTIME_SERVICES *RT;

 /**
 * The configuration.
 */
 static struct HackBGRT_config config = {
-	.action = HackBGRT_KEEP
+	.log = 1,
+	.action = HackBGRT_KEEP,
 };

 /**
@@ -28,8 +30,7 @@ static struct HackBGRT_config config = {
 static EFI_GRAPHICS_OUTPUT_PROTOCOL* GOP(void) {
 	static EFI_GRAPHICS_OUTPUT_PROTOCOL* gop;
 	if (!gop) {
-		EFI_GUID GraphicsOutputProtocolGuid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
-		LibLocateProtocol(&GraphicsOutputProtocolGuid, (VOID **)&gop);
+		LibLocateProtocol(TmpGuidPtr((EFI_GUID) EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID), (void**) &gop);
 	}
 	return gop;
 }
@@ -43,9 +44,13 @@ static EFI_GRAPHICS_OUTPUT_PROTOCOL* GOP(void) {
 static void SetResolution(int w, int h) {
 	EFI_GRAPHICS_OUTPUT_PROTOCOL* gop = GOP();
 	if (!gop) {
-		config.old_resolution_x = config.resolution_x = 0;
-		config.old_resolution_y = config.resolution_y = 0;
-		Debug(L"GOP not found!\n");
+		if (config.resolution_x <= 0 || config.resolution_y <= 0) {
+			config.resolution_x = 1024;
+			config.resolution_y = 768;
+		}
+		config.old_resolution_x = config.resolution_x;
+		config.old_resolution_y = config.resolution_y;
+		Log(config.debug, L"GOP not found! Assuming resolution %dx%d.\n", config.resolution_x, config.resolution_y);
 		return;
 	}
 	UINTN best_i = gop->Mode->Mode;
@@ -54,7 +59,7 @@ static void SetResolution(int w, int h) {
 	w = (w <= 0 ? w < 0 ? best_w : 999999 : w);
 	h = (h <= 0 ? h < 0 ? best_h : 999999 : h);

-	Debug(L"Looking for resolution %dx%d...\n", w, h);
+	Log(config.debug, L"Looking for resolution %dx%d...\n", w, h);
 	for (UINT32 i = gop->Mode->MaxMode; i--;) {
 		int new_w = 0, new_h = 0;

@@ -64,12 +69,12 @@ static void SetResolution(int w, int h) {
 			continue;
 		}
 		if (info_size < sizeof(*info)) {
-			FreePool(info);
+			BS->FreePool(info);
 			continue;
 		}
 		new_w = info->HorizontalResolution;
 		new_h = info->VerticalResolution;
-		FreePool(info);
+		BS->FreePool(info);

 		// Sum of missing w/h should be minimal.
 		int new_missing = max(w - new_w, 0) + max(h - new_h, 0);
@@ -87,7 +92,7 @@ static void SetResolution(int w, int h) {
 		best_h = new_h;
 		best_i = i;
 	}
-	Debug(L"Found resolution %dx%d.\n", best_w, best_h);
+	Log(config.debug, L"Found resolution %dx%d.\n", best_w, best_h);
 	config.resolution_x = best_w;
 	config.resolution_y = best_h;
 	if (best_i != gop->Mode->Mode) {
@@ -107,11 +112,11 @@ ACPI_SDT_HEADER* CreateXsdt(ACPI_SDT_HEADER* xsdt0, UINTN entries) {
 	UINT32 xsdt_len = sizeof(ACPI_SDT_HEADER) + entries * sizeof(UINT64);
 	BS->AllocatePool(EfiACPIReclaimMemory, xsdt_len, (void**)&xsdt);
 	if (!xsdt) {
-		Print(L"HackBGRT: Failed to allocate memory for XSDT.\n");
+		Log(1, L"Failed to allocate memory for XSDT.\n");
 		return 0;
 	}
-	ZeroMem(xsdt, xsdt_len);
-	CopyMem(xsdt, xsdt0, min(xsdt0->length, xsdt_len));
+	BS->SetMem(xsdt, xsdt_len, 0);
+	BS->CopyMem(xsdt, xsdt0, min(xsdt0->length, xsdt_len));
 	xsdt->length = xsdt_len;
 	SetAcpiSdtChecksum(xsdt);
 	return xsdt;
@@ -130,26 +135,25 @@ ACPI_SDT_HEADER* CreateXsdt(ACPI_SDT_HEADER* xsdt0, UINTN entries) {
 */
 static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt) {
 	for (int i = 0; i < ST->NumberOfTableEntries; i++) {
-		EFI_GUID Acpi20TableGuid = ACPI_20_TABLE_GUID;
 		EFI_GUID* vendor_guid = &ST->ConfigurationTable[i].VendorGuid;
-		if (!CompareGuid(vendor_guid, &AcpiTableGuid) && !CompareGuid(vendor_guid, &Acpi20TableGuid)) {
+		if (CompareMem(vendor_guid, TmpGuidPtr((EFI_GUID) ACPI_TABLE_GUID), sizeof(EFI_GUID)) != 0 && CompareMem(vendor_guid, TmpGuidPtr((EFI_GUID) ACPI_20_TABLE_GUID), sizeof(EFI_GUID)) != 0) {
 			continue;
 		}
 		ACPI_20_RSDP* rsdp = (ACPI_20_RSDP *) ST->ConfigurationTable[i].VendorTable;
 		if (CompareMem(rsdp->signature, "RSD PTR ", 8) != 0 || rsdp->revision < 2 || !VerifyAcpiRsdp2Checksums(rsdp)) {
 			continue;
 		}
-		Debug(L"RSDP @%x: revision = %d, OEM ID = %s\n", (UINTN)rsdp, rsdp->revision, TmpStr(rsdp->oem_id, 6));
+		Log(config.debug, L"RSDP @%x: revision = %d, OEM ID = %s\n", (UINTN)rsdp, rsdp->revision, TmpStr(rsdp->oem_id, 6));

 		ACPI_SDT_HEADER* xsdt = (ACPI_SDT_HEADER *) (UINTN) rsdp->xsdt_address;
 		if (!xsdt || CompareMem(xsdt->signature, "XSDT", 4) != 0 || !VerifyAcpiSdtChecksum(xsdt)) {
-			Debug(L"* XSDT: missing or invalid\n");
+			Log(config.debug, L"* XSDT: missing or invalid\n");
 			continue;
 		}
 		UINT64* entry_arr = (UINT64*)&xsdt[1];
 		UINT32 entry_arr_length = (xsdt->length - sizeof(*xsdt)) / sizeof(UINT64);

-		Debug(L"* XSDT @%x: OEM ID = %s, entry count = %d\n", (UINTN)xsdt, TmpStr(xsdt->oem_id, 6), entry_arr_length);
+		Log(config.debug, L"* XSDT @%x: OEM ID = %s, entry count = %d\n", (UINTN)xsdt, TmpStr(xsdt->oem_id, 6), entry_arr_length);

 		int bgrt_count = 0;
 		for (int j = 0; j < entry_arr_length; j++) {
@@ -157,16 +161,16 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
 			if (CompareMem(entry->signature, "BGRT", 4) != 0) {
 				continue;
 			}
-			Debug(L" - ACPI table @%x: %s, revision = %d, OEM ID = %s\n", (UINTN)entry, TmpStr(entry->signature, 4), entry->revision, TmpStr(entry->oem_id, 6));
+			Log(config.debug, L" - ACPI table @%x: %s, revision = %d, OEM ID = %s\n", (UINTN)entry, TmpStr(entry->signature, 4), entry->revision, TmpStr(entry->oem_id, 6));
 			switch (action) {
 				case HackBGRT_KEEP:
 					if (!bgrt) {
-						Debug(L" -> Returning this one for later use.\n");
+						Log(config.debug, L" -> Returning this one for later use.\n");
 						bgrt = (ACPI_BGRT*) entry;
 					}
 					break;
 				case HackBGRT_REMOVE:
-					Debug(L" -> Deleting.\n");
+					Log(config.debug, L" -> Deleting.\n");
 					for (int k = j+1; k < entry_arr_length; ++k) {
 						entry_arr[k-1] = entry_arr[k];
 					}
@@ -176,13 +180,13 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
 					--j;
 					break;
 				case HackBGRT_REPLACE:
-					Debug(L" -> Replacing.\n");
+					Log(config.debug, L" -> Replacing.\n");
 					entry_arr[j] = (UINTN) bgrt;
 			}
 			bgrt_count += 1;
 		}
 		if (!bgrt_count && action == HackBGRT_REPLACE && bgrt) {
-			Debug(L" - Adding missing BGRT.\n");
+			Log(config.debug, L" - Adding missing BGRT.\n");
 			xsdt = CreateXsdt(xsdt, entry_arr_length + 1);
 			entry_arr = (UINT64*)&xsdt[1];
 			entry_arr[entry_arr_length++] = (UINTN) bgrt;
@@ -208,7 +212,7 @@ static BMP* MakeBMP(int w, int h, UINT8 r, UINT8 g, UINT8 b) {
 	BMP* bmp = 0;
 	BS->AllocatePool(EfiBootServicesData, 54 + w * h * 4, (void**) &bmp);
 	if (!bmp) {
-		Print(L"HackBGRT: Failed to allocate a blank BMP!\n");
+		Log(1, L"Failed to allocate a blank BMP!\n");
 		BS->Stall(1000000);
 		return 0;
 	}
@@ -235,24 +239,32 @@ static BMP* MakeBMP(int w, int h, UINT8 r, UINT8 g, UINT8 b) {
 /**
 * Load a bitmap or generate a black one.
 *
- * @param root_dir The root directory for loading a BMP.
- * @param path The BMP path within the root directory; NULL for a black BMP.
+ * @param base_dir The directory for loading a BMP.
+ * @param path The BMP path within the directory; NULL for a black BMP.
 * @return The loaded BMP, or 0 if not available.
 */
-static BMP* LoadBMP(EFI_FILE_HANDLE root_dir, const CHAR16* path) {
+static BMP* LoadBMP(EFI_FILE_HANDLE base_dir, const CHAR16* path) {
 	if (!path) {
 		return MakeBMP(1, 1, 0, 0, 0); // empty path = black image
 	}
-	Debug(L"HackBGRT: Loading %s.\n", path);
+	Log(config.debug, L"Loading %s.\n", path);
 	UINTN size = 0;
-	BMP* bmp = LoadFile(root_dir, path, &size);
+	BMP* bmp = LoadFile(base_dir, path, &size);
 	if (bmp) {
-		if (size >= bmp->file_size && CompareMem(bmp, "BM", 2) == 0 && bmp->file_size - bmp->pixel_data_offset > 4 && bmp->width && bmp->height && (bmp->bpp == 32 || bmp->bpp == 24) && bmp->compression == 0) {
+		if (size >= bmp->file_size
+		&& CompareMem(bmp, "BM", 2) == 0
+		&& bmp->file_size > bmp->pixel_data_offset
+		&& bmp->width > 0
+		&& bmp->height > 0
+		&& (bmp->bpp == 32 || bmp->bpp == 24)
+		&& bmp->height * (-(-(bmp->width * (bmp->bpp / 8)) & ~3)) <= bmp->file_size - bmp->pixel_data_offset
+		&& bmp->compression == 0) {
 			return bmp;
 		}
-		Print(L"HackBGRT: Invalid BMP (%s)!\n", path);
+		BS->FreePool(bmp);
+		Log(1, L"Invalid BMP (%s)!\n", path);
 	} else {
-		Print(L"HackBGRT: Failed to load BMP (%s)!\n", path);
+		Log(1, L"Failed to load BMP (%s)!\n", path);
 	}
 	BS->Stall(1000000);
 	return MakeBMP(16, 16, 255, 0, 0); // error = red image
@@ -270,13 +282,11 @@ static void CropBMP(BMP* bmp, int w, int h) {
 	bmp->image_size = 0;
 	bmp->width = min(bmp->width, w);
 	bmp->height = min(bmp->height, h);
-	const int h_max = (bmp->file_size - bmp->pixel_data_offset) / old_pitch;
-	bmp->height = min(bmp->height, h_max);
 	const int new_pitch = -(-(bmp->width * (bmp->bpp / 8)) & ~3);

 	if (new_pitch < old_pitch) {
 		for (int i = 1; i < bmp->height; ++i) {
-			CopyMem(
+			BS->CopyMem(
 				(UINT8*) bmp + bmp->pixel_data_offset + i * new_pitch,
 				(UINT8*) bmp + bmp->pixel_data_offset + i * old_pitch,
 				new_pitch
@@ -289,9 +299,9 @@ static void CropBMP(BMP* bmp, int w, int h) {
 /**
 * The main logic for BGRT modification.
 *
- * @param root_dir The root directory for loading a BMP.
+ * @param base_dir The directory for loading a BMP.
 */
-void HackBgrt(EFI_FILE_HANDLE root_dir) {
+void HackBgrt(EFI_FILE_HANDLE base_dir) {
 	// REMOVE: simply delete all BGRT entries.
 	if (config.action == HackBGRT_REMOVE) {
 		HandleAcpiTables(config.action, 0);
@@ -320,7 +330,7 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 		// Replace missing = allocate new.
 		BS->AllocatePool(EfiACPIReclaimMemory, sizeof(*bgrt), (void**)&bgrt);
 		if (!bgrt) {
-			Print(L"HackBGRT: Failed to allocate memory for BGRT.\n");
+			Log(1, L"Failed to allocate memory for BGRT.\n");
 			return;
 		}
 	}
@@ -342,7 +352,7 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 	// Get the image (either old or new).
 	BMP* new_bmp = old_bmp;
 	if (config.action == HackBGRT_REPLACE) {
-		new_bmp = LoadBMP(root_dir, config.image_path);
+		new_bmp = LoadBMP(base_dir, config.image_path);
 	}

 	// No image = no need for BGRT.
@@ -372,8 +382,8 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 	bgrt->image_offset_x = max(0, min(max_x, new_x + (new_reso_x - new_bmp->width) / 2));
 	bgrt->image_offset_y = max(0, min(max_y, new_y + (new_reso_y - new_bmp->height) / 2));

-	Debug(
-		L"HackBGRT: BMP at (%d, %d), center (%d, %d), resolution (%d, %d) with orientation %d applied.\n",
+	Log(config.debug,
+		L"BMP at (%d, %d), center (%d, %d), resolution (%d, %d), orientation %d.\n",
 		(int) bgrt->image_offset_x, (int) bgrt->image_offset_y,
 		new_x, new_y, new_reso_x, new_reso_y,
 		new_orientation * 90
@@ -387,12 +397,12 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 /**
 * Load an application.
 */
-static EFI_HANDLE LoadApp(print_t* print_failure, EFI_HANDLE image_handle, EFI_LOADED_IMAGE* image, const CHAR16* path) {
+static EFI_HANDLE LoadApp(int print_failure, EFI_HANDLE image_handle, EFI_LOADED_IMAGE* image, const CHAR16* path) {
 	EFI_DEVICE_PATH* boot_dp = FileDevicePath(image->DeviceHandle, (CHAR16*) path);
 	EFI_HANDLE result = 0;
-	Debug(L"HackBGRT: Loading application %s.\n", path);
+	Log(config.debug, L"Loading application %s.\n", path);
 	if (EFI_ERROR(BS->LoadImage(0, image_handle, boot_dp, 0, 0, &result))) {
-		print_failure(L"HackBGRT: Failed to load application %s.\n", path);
+		Log(config.debug || print_failure, L"Failed to load application %s.\n", path);
 	}
 	return result;
 }
@@ -400,98 +410,116 @@ static EFI_HANDLE LoadApp(print_t* print_failure, EFI_HANDLE image_handle, EFI_L
 /**
 * The main program.
 */
-EFI_STATUS EFIAPI EfiMain(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *ST_) {
-	InitializeLib(image_handle, ST_);
+EFI_STATUS EFIAPI efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *ST_) {
+	ST = ST_;
+	BS = ST_->BootServices;
+	RT = ST_->RuntimeServices;
+
+	// Clear the screen to wipe the vendor logo.
+	ST->ConOut->EnableCursor(ST->ConOut, 0);
+	ST->ConOut->ClearScreen(ST->ConOut);
+
+	Log(0, L"HackBGRT version: %s\n", version);

 	EFI_LOADED_IMAGE* image;
-	if (EFI_ERROR(BS->HandleProtocol(image_handle, &LoadedImageProtocol, (void**) &image))) {
-		Debug(L"HackBGRT: LOADED_IMAGE_PROTOCOL failed.\n");
+	if (EFI_ERROR(BS->HandleProtocol(image_handle, TmpGuidPtr((EFI_GUID) EFI_LOADED_IMAGE_PROTOCOL_GUID), (void**) &image))) {
+		Log(config.debug, L"LOADED_IMAGE_PROTOCOL failed.\n");
 		goto fail;
 	}

-	EFI_FILE_HANDLE root_dir = LibOpenRoot(image->DeviceHandle);
+	EFI_FILE_IO_INTERFACE* io;
+	if (EFI_ERROR(BS->HandleProtocol(image->DeviceHandle, TmpGuidPtr((EFI_GUID) EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID), (void**) &io))) {
+		Log(config.debug, L"FILE_SYSTEM_PROTOCOL failed.\n");
+		goto fail;
+	}

-	CHAR16 **argv;
-	int argc = GetShellArgcArgv(image_handle, &argv);
+	EFI_FILE_HANDLE root_dir;
+	if (EFI_ERROR(io->OpenVolume(io, &root_dir))) {
+		Log(config.debug, L"Failed to open root directory.\n");
+		goto fail;
+	}

-	if (argc <= 1) {
-		const CHAR16* config_path = L"\\EFI\\HackBGRT\\config.txt";
-		if (!ReadConfigFile(&config, root_dir, config_path)) {
-			Print(L"HackBGRT: No config, no command line!\n", config_path);
+	EFI_FILE_HANDLE base_dir;
+	if (EFI_ERROR(root_dir->Open(root_dir, &base_dir, L"\\EFI\\HackBGRT", EFI_FILE_MODE_READ, 0))) {
+		Log(config.debug, L"Failed to HackBGRT directory.\n");
+		base_dir = root_dir;
+	}
+
+	EFI_SHELL_PARAMETERS_PROTOCOL *shell_param_proto = NULL;
+	if (EFI_ERROR(BS->OpenProtocol(image_handle, TmpGuidPtr((EFI_GUID) EFI_SHELL_PARAMETERS_PROTOCOL_GUID), (void**) &shell_param_proto, 0, 0, EFI_OPEN_PROTOCOL_GET_PROTOCOL)) || shell_param_proto->Argc <= 1) {
+		const CHAR16* config_path = L"config.txt";
+		if (!ReadConfigFile(&config, base_dir, config_path)) {
+			Log(1, L"No config, no command line!\n", config_path);
 			goto fail;
 		}
+	} else {
+		CHAR16 **argv = shell_param_proto->Argv;
+		int argc = shell_param_proto->Argc;
+		for (int i = 1; i < argc; ++i) {
+			ReadConfigLine(&config, base_dir, argv[i]);
+		}
 	}
-	for (int i = 1; i < argc; ++i) {
-		ReadConfigLine(&config, root_dir, argv[i]);
+
+	if (config.debug) {
+		Log(-1, L"HackBGRT version: %s\n", version);
 	}
-	Debug = config.debug ? Print : NullPrint;

 	SetResolution(config.resolution_x, config.resolution_y);
-	HackBgrt(root_dir);
+	HackBgrt(base_dir);

 	EFI_HANDLE next_image_handle = 0;
 	static CHAR16 backup_boot_path[] = L"\\EFI\\HackBGRT\\bootmgfw-original.efi";
 	static CHAR16 ms_boot_path[] = L"\\EFI\\Microsoft\\Boot\\bootmgfw.efi";
+	int try_ms_quietly = 1;

 	if (config.boot_path && StriCmp(config.boot_path, L"MS") != 0) {
-		next_image_handle = LoadApp(Print, image_handle, image, config.boot_path);
-	} else {
-		config.boot_path = backup_boot_path;
-		next_image_handle = LoadApp(Debug, image_handle, image, config.boot_path);
-		if (!next_image_handle) {
-			config.boot_path = ms_boot_path;
-			next_image_handle = LoadApp(Debug, image_handle, image, config.boot_path);
-		}
+		next_image_handle = LoadApp(1, image_handle, image, config.boot_path);
+		try_ms_quietly = 0;
 	}
 	if (!next_image_handle) {
 		config.boot_path = backup_boot_path;
-		next_image_handle = LoadApp(Print, image_handle, image, config.boot_path);
+		next_image_handle = LoadApp(!try_ms_quietly, image_handle, image, config.boot_path);
 		if (!next_image_handle) {
 			config.boot_path = ms_boot_path;
-			next_image_handle = LoadApp(Print, image_handle, image, config.boot_path);
+			next_image_handle = LoadApp(!try_ms_quietly, image_handle, image, config.boot_path);
 			if (!next_image_handle) {
 				goto fail;
 			}
 		}
-		Print(L"HackBGRT: Reverting to %s.\n", config.boot_path);
-		Print(L"Press escape to cancel or any other key (or wait 15 seconds) to boot.\n");
+		if (try_ms_quietly) {
+			goto ready_to_boot;
+		}
+		Log(1, L"Reverting to %s.\n", config.boot_path);
+		Log(-1, L"Press escape to cancel or any other key (or wait 15 seconds) to boot.\n");
 		if (ReadKey(15000).ScanCode == SCAN_ESC) {
 			goto fail;
 		}
-	} else if (config.debug) {
-		Print(L"HackBGRT: Ready to boot. Disable debug mode to skip this screen.\n");
-		Print(L"Press escape to cancel or any other key (or wait 15 seconds) to boot.\n");
+	} else ready_to_boot: if (config.debug) {
+		Log(-1, L"Ready to boot.\n");
+		Log(-1, L"If all goes well, you can set debug=0 and log=0 in config.txt.\n");
+		Log(-1, L"Press escape to cancel or any other key (or wait 15 seconds) to boot.\n");
 		if (ReadKey(15000).ScanCode == SCAN_ESC) {
 			return 0;
 		}
 	}
+	if (!config.log) {
+		ClearLogVariable();
+	}
 	if (EFI_ERROR(BS->StartImage(next_image_handle, 0, 0))) {
-		Print(L"HackBGRT: Failed to start %s.\n", config.boot_path);
+		Log(1, L"Failed to start %s.\n", config.boot_path);
 		goto fail;
 	}
-	Print(L"HackBGRT: Started %s. Why are we still here?!\n", config.boot_path);
-	Print(L"Please check that %s is not actually HackBGRT!\n", config.boot_path);
+	Log(1, L"Started %s. Why are we still here?!\n", config.boot_path);
+	Log(-1, L"Please check that %s is not actually HackBGRT!\n", config.boot_path);
 	goto fail;

 	fail: {
-		Print(L"HackBGRT has failed. Use parameter debug=1 for details.\n");
-		Print(L"Get a Windows install disk or a recovery disk to fix your boot.\n");
-		#ifdef GIT_DESCRIBE
-			Print(L"HackBGRT version: " GIT_DESCRIBE L"\n");
-		#else
-			Print(L"HackBGRT version: unknown; not an official release?\n");
-		#endif
-		Print(L"Press any key (or wait 15 seconds) to exit.\n");
+		Log(1, L"HackBGRT has failed.\n");
+		Log(-1, L"Dumping log:\n\n");
+		DumpLog();
+		Log(-1, L"If you can't boot into Windows, get install/recovery disk to fix your boot.\n");
+		Log(-1, L"Press any key (or wait 15 seconds) to exit.\n");
 		ReadKey(15000);
 		return 1;
 	}
 }
-
-/**
- * Forward to EfiMain.
- *
- * Some compilers and architectures differ in underscore handling. This helps.
- */
-EFI_STATUS EFIAPI _EfiMain(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *ST_) {
-	return EfiMain(image_handle, ST_);
-}
--- a/src/sbat.c
+++ b/src/sbat.c
@@ -0,0 +1,10 @@
+#ifdef GIT_DESCRIBE
+#define SBAT_READABLE_VERSION GIT_DESCRIBE
+#else
+#define SBAT_READABLE_VERSION "unknown"
+#endif
+
+const char sbat[] __attribute__ ((section (".sbat"))) =
+"sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md\n"
+"hackbgrt,1,Metabolix,HackBGRT," SBAT_READABLE_VERSION ",https://github.com/Metabolix/HackBGRT\n"
+;
--- a/src/types.h
+++ b/src/types.h
@@ -1,6 +1,6 @@
 #pragma once

-#include <efi.h>
+#include "efi.h"

 #pragma pack(push, 1)

--- a/src/util.c
+++ b/src/util.c
@@ -1,7 +1,5 @@
 #include "util.h"

-#include <efilib.h>
-
 const CHAR16* TmpStr(CHAR8 *src, int length) {
 	static CHAR16 arr[4][16];
 	static int j;
@@ -14,8 +12,99 @@ const CHAR16* TmpStr(CHAR8 *src, int length) {
 	return dest;
 }

-UINTN NullPrint(IN CONST CHAR16 *fmt, ...) {
-	return 0;
+const CHAR16* TmpIntToStr(UINT32 x) {
+	static CHAR16 buf[20];
+	int i = 20 - 1;
+	buf[i] = 0;
+	if (!x) {
+		buf[--i] = '0';
+	}
+	while (x && i) {
+		buf[--i] = '0' + (x % 10);
+		x /= 10;
+	}
+	return &buf[i];
+}
+
+#define log_buffer_size (65536)
+CHAR16 log_buffer[log_buffer_size] = {0};
+
+CHAR16 LogVarName[] = L"HackBGRTLog";
+EFI_GUID LogVarGuid = {0x03c64761, 0x075f, 0x4dba, {0xab, 0xfb, 0x2e, 0xd8, 0x9e, 0x18, 0xb2, 0x36}}; // self-made: 03c64761-075f-4dba-abfb-2ed89e18b236
+
+void Log(int mode, IN CONST CHAR16 *fmt, ...) {
+	va_list args;
+	CHAR16 buf[256] = {0};
+	int buf_i = 0;
+	#define putchar(c) { if (buf_i < 255) { buf[buf_i++] = c; } }
+	va_start(args, fmt);
+	for (int i = 0; fmt[i]; ++i) {
+		if (fmt[i] == '\n') {
+			putchar('\r');
+			putchar('\n');
+			continue;
+		}
+		if (fmt[i] != '%') {
+			putchar(fmt[i]);
+			continue;
+		}
+		++i;
+		switch (fmt[i]) {
+			case '%': putchar('%'); continue;
+			case 'd': goto fmt_decimal;
+			case 'x': goto fmt_hex;
+			case 's': goto fmt_string;
+			case 0: goto fmt_end;
+		}
+		putchar('%');
+		putchar(fmt[i]);
+		continue;
+
+		if (0) fmt_decimal: {
+			INT32 x = va_arg(args, INT32);
+			if (x < 0) {
+				putchar('-');
+				x = -x;
+			}
+			const CHAR16* s = TmpIntToStr(x);
+			while (*s) {
+				putchar(*s++);
+			}
+		}
+		if (0) fmt_hex: {
+			UINT32 x = va_arg(args, UINT32);
+			for (int pos = 8, started = 0; pos--;) {
+				int d = (x >> (4 * pos)) & 0xf;
+				if (d || started || pos == 0) {
+					putchar("0123456789abcdef"[d]);
+					started = 1;
+				}
+			}
+		}
+		if (0) fmt_string: {
+			CHAR16* s = va_arg(args, CHAR16*);
+			while (*s) {
+				putchar(*s++);
+			}
+		}
+	}
+	fmt_end:
+	va_end(args);
+	if (mode) {
+		ST->ConOut->OutputString(ST->ConOut, buf);
+	}
+	if (mode != -1) {
+		StrnCat(log_buffer, buf, log_buffer_size - StrLen(log_buffer) - 1);
+		RT->SetVariable(LogVarName, &LogVarGuid, EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, StrLen(log_buffer) * 2, log_buffer);
+	}
+}
+
+void DumpLog(void) {
+	ST->ConOut->OutputString(ST->ConOut, log_buffer);
+}
+
+void ClearLogVariable(void) {
+	RT->SetVariable(LogVarName, &LogVarGuid, EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, 0, 0);
 }

 const CHAR16* TrimLeft(const CHAR16* s) {
@@ -71,11 +160,24 @@ void RandomSeedAuto(void) {
 EFI_STATUS WaitKey(UINT64 timeout_ms) {
 	ST->ConIn->Reset(ST->ConIn, FALSE);
 	const int ms_to_100ns = 10000;
-	return WaitForSingleEvent(ST->ConIn->WaitForKey, timeout_ms * ms_to_100ns);
+
+	EFI_EVENT events[2] = {ST->ConIn->WaitForKey};
+	EFI_STATUS status = BS->CreateEvent(EVT_TIMER, 0, NULL, NULL, &events[1]);
+	if (!EFI_ERROR(status)) {
+		BS->SetTimer(events[1], TimerRelative, timeout_ms * ms_to_100ns);
+		UINTN index;
+		status = BS->WaitForEvent(2, events, &index);
+		BS->CloseEvent(events[1]);
+		if (!EFI_ERROR(status) && index == 1) {
+			status = EFI_TIMEOUT;
+		}
+	}
+	return status;
 }

 EFI_INPUT_KEY ReadKey(UINT64 timeout_ms) {
 	EFI_INPUT_KEY key = {0};
+	ST->ConOut->EnableCursor(ST->ConOut, 1);
 	WaitKey(timeout_ms);
 	ST->ConIn->ReadKeyStroke(ST->ConIn, &key);
 	return key;
@@ -90,9 +192,11 @@ void* LoadFileWithPadding(EFI_FILE_HANDLE dir, const CHAR16* path, UINTN* size_p
 		return 0;
 	}

-	EFI_FILE_INFO *info = LibFileInfo(handle);
-	UINTN size = info->FileSize;
-	FreePool(info);
+	UINT64 get_size = 0;
+	handle->SetPosition(handle, ~(UINT64)0);
+	handle->GetPosition(handle, &get_size);
+	handle->SetPosition(handle, 0);
+	UINTN size = (UINTN) get_size;

 	void* data = 0;
 	e = BS->AllocatePool(EfiBootServicesData, size + padding, &data);
@@ -106,7 +210,7 @@ void* LoadFileWithPadding(EFI_FILE_HANDLE dir, const CHAR16* path, UINTN* size_p
 	}
 	handle->Close(handle);
 	if (EFI_ERROR(e)) {
-		FreePool(data);
+		BS->FreePool(data);
 		return 0;
 	}
 	if (size_ptr) {
--- a/src/util.h
+++ b/src/util.h
@@ -1,6 +1,6 @@
 #pragma once

-#include <efi.h>
+#include "efi.h"

 /**
 * Convert a short ASCII string to UCS2, store in a static array.
@@ -12,9 +12,22 @@
 extern const CHAR16* TmpStr(CHAR8 *src, int length);

 /**
- * Empty function that has the same signature as Print.
+ * Print or log a string.
+ *
+ * @param mode -1 = print without logging, 0 = no, 1 = yes.
+ * @param fmt The format string. Supports %d, %x, %s.
 */
-extern UINTN NullPrint(IN CONST CHAR16 *fmt, ...);
+extern void Log(int mode, IN CONST CHAR16 *fmt, ...);
+
+/**
+ * Dump the log buffer to the screen.
+ */
+extern void DumpLog(void);
+
+/**
+ * Clear the log EFI variable, for minor RAM savings.
+ */
+extern void ClearLogVariable(void);

 /**
 * Return the greater of two numbers.
@@ -107,3 +120,11 @@ static inline void* LoadFile(EFI_FILE_HANDLE dir, const CHAR16* path, UINTN* siz
 	return LoadFileWithPadding(dir, path, size_ptr, 0);
 }

+/**
+ * Get a temporary pointer to GUID.
+ */
+static inline EFI_GUID* TmpGuidPtr(EFI_GUID guid) {
+	static EFI_GUID g;
+	g = guid;
+	return &g;
+}
Author	SHA1	Message	Date
Lauri Kenttä	b9e23c91a3	Update change log and tag 2.4.1	2024-04-11 17:48:55 +03:00
Lauri Kenttä	697c57355b	Disable old version before copying files Apparently some people still have the obsolete v1.5.1 installed and manage to break things by copying v2.x config in place.	2024-04-11 17:46:13 +03:00
Lauri Kenttä	da16365508	Report if BCDEdit is not working One possible cause for BCDEdit failure is Windows error 0x800703EE. "The volume for a file has been externally altered so that the opened file is no longer valid." Suggested solutions include disabling antivirus or backup software.	2024-04-11 17:46:13 +03:00
Lauri Kenttä	665a4732ca	Detect device paths which contain extra data Apparently some firmware may add extra data to the device path, so exit the loop on the first end-of-path record. Fixes GH issue #181.	2024-03-24 17:27:02 +02:00
Lauri Kenttä	39596aadfc	Don't try to remove non-existent dir.	2024-01-20 12:43:00 +02:00
Lauri Kenttä	1a5b1df064	Update change log and tag 2.4.0	2023-12-31 18:35:35 +02:00
Lauri Kenttä	ea70f3ce79	Disable before enabling, and default to BCDEdit	2023-12-31 18:29:48 +02:00
Lauri Kenttä	a44b929012	Fix a shim error caused by bad load options data Shim expects a filename or nothing in the load options. To avoid an error message during boot, do several things: When creating the NVRAM entry, use empty load options. The current string ("HackBGRT\0") was just a decoration, and it's luckily ignored by shim because the length is odd. When creating the entry with BCDEdit, manually fix the load options. The load options in BCDEdit entries start with "WINDOWS\0" followed by UINT32 version, as seen in ReactOS struct BL_WINDOWS_LOAD_OPTIONS. The version is 1, but BCDEdit seems to be happy with a higher number. By setting this version to 'X' (0x58), the string becomes a valid UCS-2 file name. Update the installer so that the HackBGRT loader is installed with this weird file name. The reason why the load options cannot be deleted completely is that BCDEdit will recreate the entry on next boot if it doesn't find the entry it just tried to create. See: https://github.com/rhboot/shim/pull/621 See: https://github.com/reactos/reactos/blob/v0.4.7/boot/environ/include/bl.h#L911	2023-12-31 18:20:27 +02:00
Lauri Kenttä	9948e5a306	Fix BCDEdit dry run and add more logging	2023-12-31 17:50:14 +02:00
Lauri Kenttä	518d7c8a97	Show proper message if boot log is empty	2023-12-20 18:29:34 +02:00
Lauri Kenttä	c6108ffd62	Warn about old .Net version if methods are missing	2023-12-20 18:29:25 +02:00
Lauri Kenttä	6dc447a8ce	Try to avoid some .Net Framework 4.8 features	2023-12-20 18:29:25 +02:00
Lauri Kenttä	5ec17a49e8	Detect ARM arch from MS loader	2023-12-20 18:29:25 +02:00
Lauri Kenttä	7b7309a255	Explain why the original logo is still visible	2023-12-20 18:29:25 +02:00
Lauri Kenttä	a82646a822	Wipe the vendor logo as soon as possible Loading the image might take some minimal time. Optimize experience. Hide cursor as well but restore it in ReadKey.	2023-12-20 18:27:19 +02:00
Lauri Kenttä	294da9c069	Get rid of \EFI\HackBGRT\ in config.txt	2023-12-16 15:13:05 +02:00
Lauri Kenttä	4096002eb2	Update issue templates	2023-12-16 15:03:05 +02:00
Lauri Kenttä	835cc1b2f2	Update change log and tag v2.3.1	2023-11-27 18:57:20 +02:00
Lauri Kenttä	74a143e723	Make BitLocker detection more reliable	2023-11-27 18:57:08 +02:00
Lauri Kenttä	b75dbe13c7	Update change log and tag v2.3.0	2023-11-27 15:33:31 +02:00
Lauri Kenttä	ba72b90082	Add logging to verify entry creation	2023-11-27 15:19:46 +02:00
Lauri Kenttä	6b724d5590	Don't create entries higher than Boot00FF Apparently Boot20## are sometimes reserved for firmware even if they seem to be free. Boot00## is the normal place to be.	2023-11-27 15:19:06 +02:00
Lauri Kenttä	9ebe4e2476	Add run-qemu-<arch> to Makefile The exact command may vary by OS, this is for Arch Linux.	2023-11-25 20:04:54 +02:00
Lauri Kenttä	5111897fae	Update Makefile (instructions, release)	2023-11-25 20:04:54 +02:00
Lauri Kenttä	aac8a38cbb	Don't print HackBGRT on every output line	2023-11-25 20:02:53 +02:00
Lauri Kenttä	77dd2bd699	If GOP is missing, use config.txt resolution or 1024x768	2023-11-25 20:02:01 +02:00
Lauri Kenttä	8dfa456a7b	Fix ARM (32-bit) build Use -O, because -O2 causes Undefined OpCode in QEMU / UEFI Shell. Remove -mno-red-zone which triggers -Wunused-command-line-argument. Set architecture in PE file manually: EFI uses IMAGE_FILE_MACHINE_ARMTHUMB_MIXED = 0x01C2, while the default is IMAGE_FILE_MACHINE_ARMNT = 0x01C4.	2023-11-25 19:16:43 +02:00
Lauri Kenttä	7ccdcc4a77	Add ARM (32-bit) target (without shim, though) Remove some integer divisions because they emit function calls.	2023-11-20 19:45:28 +02:00
Lauri Kenttä	50e84e8c90	Add AArch64 target	2023-11-20 19:45:28 +02:00
Lauri Kenttä	24c7e2b316	Switch to Clang Clang can cross-compile to PE and is easier to setup than MinGW.	2023-11-20 19:45:28 +02:00
Lauri Kenttä	4379f9cbeb	Add gnu-efi submodule for headers, don't link, just re-implement some functions	2023-11-20 19:42:23 +02:00
Lauri Kenttä	2a0f2a7757	Get shell arguments without gnu-efi	2023-11-20 19:31:25 +02:00
Lauri Kenttä	ebbacb72bb	Open ESP root dir without gnu-efi	2023-11-20 19:31:25 +02:00
Lauri Kenttä	a908036ee8	Implement WaitKey without gnu-efi	2023-11-20 19:31:25 +02:00
Lauri Kenttä	57ce3ae33e	Avoid using gnu-efi static global GUIDs	2023-11-20 19:31:25 +02:00
Lauri Kenttä	7dd048346d	Use EFI BS FreePool, SetMem, CopyMem	2023-11-20 19:31:25 +02:00
Lauri Kenttä	0dfc49c800	Re-implement string formatting (%s, %d, %x)	2023-11-20 19:31:25 +02:00
Lauri Kenttä	4e50b33636	Check BMP pixel data size when loading	2023-11-20 19:31:25 +02:00
Lauri Kenttä	5856d25b5b	Update change log and tag v2.2.0	2023-11-17 23:24:58 +02:00
Lauri Kenttä	466ab69c48	Use shim 15.7 to support Secure Boot Use shim-signed and shim-helpers-{arch}-signed from Debian: https://packages.debian.org/bookworm/shim-signed	2023-11-17 23:24:58 +02:00
Lauri Kenttä	14aa79929a	Easily override GIT_DESCRIBE	2023-11-17 23:13:12 +02:00
Lauri Kenttä	5e32a3f880	Add clean target to Makefile	2023-11-17 23:13:12 +02:00
Lauri Kenttä	db934099df	Gather log during boot	2023-11-17 23:13:12 +02:00
Lauri Kenttä	e93ed54cb2	Make setup menu shorter	2023-11-17 22:47:29 +02:00
Lauri Kenttä	9b3b045a21	Add SBAT section to the EFI binaries	2023-11-17 22:26:43 +02:00
Lauri Kenttä	be8a5d35d2	Sign the EFI files	2023-11-17 22:26:43 +02:00
Lauri Kenttä	2366fc8b98	Warn about Fast Startup (Hiberboot)	2023-11-16 22:56:10 +02:00
Lauri Kenttä	e04ba3e451	Log boot entries during setup	2023-11-16 22:07:08 +02:00
Lauri Kenttä	f40f2bc9dc	Clarify LogBGRT output for corner cases	2023-11-09 21:46:39 +02:00
Lauri Kenttä	2f572b24d4	Free BMP if it's invalid	2023-11-09 21:46:35 +02:00