Update change log and tag v2.2.0

Use shim-signed and shim-helpers-{arch}-signed from Debian:
https://packages.debian.org/bookworm/shim-signed

CHANGELOG.md

@@ -2,6 +2,49 @@
 
 All notable changes to this project will be documented in this file.
 
+## 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
+- Check image size, crop if it's bigger than the screen.
+- Check BitLocker status to avoid unbootable machine.
+
+## 2.0.0 - 2023-09-10
+
+### Added
+- Log to `setup.log`.
+- Image conversion (GIF, EXIF, JPG, PNG, TIFF) to BMP during setup.
+- Quiet (batch) setup.
+- Dry run in setup.
+- EFI boot entry support in setup.
+- Orientation parameter (o=0|90|180|270) for images.
+
+### Changed
+- Configure (edit config and images) before installing.
+- Escalate privileges only when needed (after the menu).
+- Try to detect and avoid some configuration errors.
+- Wait at most 15 seconds for key presses during boot.
+- Image coordinates are now relative to the center.
+
+## 1.5.1 - 2018-08-11
+
+### Fixed
+- Clarify the default config.txt.
+- Fix an exception in some cases when trying to boot to UEFI setup.
+
+## 1.5.0 - 2017-09-30
+
+### Added
+- Support for rebooting to UEFI setup.
+
+### Changed
+- Minor enhancements to installer.
+
 ## 1.4.0 - 2017-08-29
 
 ### Added

Makefile

@@ -7,37 +7,65 @@ LIBS    = -L$(GNUEFI_LIB) -lefi -lgcc
 GNUEFI_INC = /usr/$(CC_PREFIX)/include/efi
 GNUEFI_LIB = /usr/$(CC_PREFIX)/lib
 
-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
 FILES_H = $(wildcard src/*.h)
-GIT_DESCRIBE = $(firstword $(shell git describe --tags) unknown)
-CFLAGS += '-DGIT_DESCRIBE=L"$(GIT_DESCRIBE)"'
+FILES_CS = src/Setup.cs src/Esp.cs src/Efi.cs
+GIT_DESCRIBE := $(firstword $(GIT_DESCRIBE) $(shell git describe --tags) unknown)
+CFLAGS += '-DGIT_DESCRIBE_W=L"$(GIT_DESCRIBE)"' '-DGIT_DESCRIBE="$(GIT_DESCRIBE)"'
 ZIPDIR = HackBGRT-$(GIT_DESCRIBE:v%=%)
 ZIP = $(ZIPDIR).zip
 
-efi: bootx64.efi bootia32.efi
-setup: setup.exe
+.PHONY: all efi efi-signed setup zip clean
+
 all: efi setup
+efi: efi/bootx64.efi efi/bootia32.efi
+efi-signed: efi-signed/bootx64.efi efi-signed/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
+$(ZIP): efi-signed certificate.cer config.txt splash.bmp setup.exe README.md CHANGELOG.md README.efilib LICENSE shim-signed shim.md
 	test ! -d "$(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)"
 
-src/GIT_DESCRIBE.cs: src/Setup.cs $(FILES_C) $(FILES_H)
-	echo 'public class GIT_DESCRIBE { public static string data = "$(GIT_DESCRIBE)"; }' > $@
+src/GIT_DESCRIBE.cs: $(FILES_CS) $(FILES_C) $(FILES_H)
+	echo 'public class GIT_DESCRIBE { public const string data = "$(GIT_DESCRIBE)"; }' > $@
 
-setup.exe: src/Setup.cs src/GIT_DESCRIBE.cs
-	mcs -define:GIT_DESCRIBE -out:$@ $^
+setup.exe: $(FILES_CS) src/GIT_DESCRIBE.cs
+	csc /define:GIT_DESCRIBE /out:$@ $^
 
-bootx64.efi: CC_PREFIX = x86_64-w64-mingw32
-bootx64.efi: GNUEFI_ARCH = x86_64
-bootx64.efi: $(FILES_C)
+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
+
+efi-signed/%.efi: efi/%.efi
+	mkdir -p efi-signed
+	pesign --force -n pki -i $< -o $@ -c HackBGRT-signer -s
+
+efi-signed/bootx64.efi: pki
+efi-signed/bootia32.efi: pki
+
+efi/bootx64.efi: CC_PREFIX = x86_64-w64-mingw32
+efi/bootx64.efi: GNUEFI_ARCH = x86_64
+efi/bootx64.efi: $(FILES_C)
+	@mkdir -p efi
 	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ $(LIBS) -s
 
-bootia32.efi: CC_PREFIX = i686-w64-mingw32
-bootia32.efi: GNUEFI_ARCH = ia32
-bootia32.efi: $(FILES_C)
+efi/bootia32.efi: CC_PREFIX = i686-w64-mingw32
+efi/bootia32.efi: GNUEFI_ARCH = ia32
+efi/bootia32.efi: $(FILES_C)
+	@mkdir -p efi
 	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ $(LIBS) -s
+
+clean:
+	rm -rf setup.exe efi efi-signed

README.md

@@ -4,52 +4,83 @@ HackBGRT is intended as a boot logo changer for UEFI-based Windows systems.
 
 ## Summary
 
-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 permamently, but a custom UEFI application may be used to overwrite it during the boot. HackBGRT does exactly that.
+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.
 
 ## 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, or learn to sign EFI applications.
-* Simple Windows installation:
-	* Get the latest release.
-	* Start `setup.exe` and select `I` (install).
-	* The installer will launch Notepad for modifying the configuration.
-		* If you need only one custom image, the defaults are fine.
-		* Otherwise, check out the examples in the configuration file.
-	* The installer will launch Paint for creating the image(s).
-		* You can create multiple images by using Save As.
-		* Be sure to always use the 24-bit BMP/DIB format.
-	* If Windows later restores the original boot loader, simply reinstall.
-	* If you wish to change the image or other configuration, simply reinstall.
-* Installation for Windows with another boot loader (e.g. GRUB):
-	* Extract the latest release to `[EFI System Partition]\EFI\HackBGRT\`.
-	* Set `boot=\EFI\Microsoft\Boot\bootmgfw.efi` in `config.txt`.
-	* Point your boot loader to `\EFI\HackBGRT\bootx64.efi`.
-* Installation for all operating systems:
-	* Extract the latest release to `[EFI System Partition]\EFI\HackBGRT\`.
-	* Set `boot=` to your preferred boot loader in `config.txt`.
-	* Set `\EFI\HackBGRT\bootx64.efi` as your default boot loader with `efibootmgr` or some other EFI boot manager tool.
+* 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.
+	* 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
+
+* Edit the `config.txt` and `splash.bmp` (or any other images) to your needs.
+* Run `setup.exe batch COMMANDS` as administrator, with some of the following commands:
+	* `install` – copy the files but don't enable.
+	* `enable-entry` – create a new EFI boot entry.
+	* `disable-entry` – disable the EFI boot entry.
+	* `enable-bcdedit` – use `bcdedit` to create a new EFI boot entry.
+	* `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
+
+If you only need HackBGRT for Windows:
+
+* Run `setup.exe`, install files without enabling.
+* Configure your boot loader to start `\EFI\HackBGRT\loader.efi`.
+
+If you need it for other systems as well:
+
+* Configure HackBGRT to start your boot loader (such as systemd-boot): `boot=\EFI\systemd\systemd-bootx64.efi`.
+* Run `setup.exe`, install as a new EFI boot entry.
+
+To install purely on Linux, you can install with `setup.exe dry-run` and then manually copy files from `dry-run/EFI` to your `[EFI System Partition]/EFI`. For further instructions, consult the documentation of your own Linux system.
 
 ## Configuration
 
-The configuration options are described in `config.txt`, which should be stored in `[EFI System Partition]\EFI\HackBGRT\config.txt`.
+The configuration options are described in `config.txt`, which the installer copies into `[EFI System Partition]\EFI\HackBGRT\config.txt`.
 
 ## Images
 
 The image path can be changed in the configuration file. The default path is `[EFI System Partition]\EFI\HackBGRT\splash.bmp`.
 
-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.
+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`.
 
-Multiple images may be specified, in which case one is picked at random.
+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 have the following options:
-
-* Windows installation (or recovery) media can fix boot issues.
-* You can copy `[EFI System Partition]\EFI\HackBGRT\bootmgfw-original.efi` into `[EFI System Partition]\EFI\Microsoft\Boot\bootmgfw.efi` by some other means such as Linux or Windows command prompt.
+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
 

config.txt

@@ -1,35 +1,48 @@
 # vim: set fileencoding=utf-8
 # The same options may be given also as command line parameters in the EFI Shell, which is useful for debugging.
 
-# Boot loader path. Point to the real Windows boot loader.
-boot=\EFI\HackBGRT\bootmgfw-original.efi
+# Boot loader path. MS = either backup or original Windows boot loader.
+boot=MS
 
 # The image is specified with an image line.
 # Multiple image lines may be present, in which case one will be picked by random.
 # The image line may contain the following parts:
 # Any of the following:
-#  - "n=[0-9]+", a weight for this image in the randomization process. Default: n=1.
-#  - "x={auto|native|[0-9]+}", the x coordinate. Default: x=auto.
-#  - "y={auto|native|[0-9]+}", the y coordinate. Default: y=auto.
+#  - "n=(number)", a weight for this image in the randomization process. Default: n=1.
+#  - "x=(number)" or "x=keep", the x offset from the center. Default: x=0.
+#  - "y=(number)" or "y=keep", the y offset from the center. Default: y=0.
+#  - "o=(0|90|180|270|keep)", the screen orientation, degrees anticlockwise. Default: o=keep.
 # One of the following:
-#  - "keep" to keep the firmware logo. Sets also x=native,y=native by default.
+#  - "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. The file must be a 24-bit BMP file with a 54-byte header.
+#  - "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!
 # Examples:
 #  - image=remove
 #  - image=black
-#  - image=x=auto,y=0,path=\EFI\HackBGRT\topimage.bmp
-#  - image=n=1,path=\EFI\HackBGRT\splash.bmp
-#  - image=n=50,path=\EFI\HackBGRT\probable.bmp
+#  - 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
 # The above examples together would produce
 #  - 1/54 chance for the default OS logo
 #  - 1/54 chance for black screen
-#  - 1/54 chance for topimage.bmp, centered at the top of the screen
-#  - 1/54 chance for splash.bmp, automatically positioned
-#  - 50/54 chance for probable.bmp, automatically positioned
+#  - 1/54 chance for topimage.bmp, 200 px above the center of the screen
+#  - 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=path=\EFI\HackBGRT\splash.bmp
+image= y=-200 path=\EFI\HackBGRT\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

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.

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.

src/Efi.cs

@@ -0,0 +1,518 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Linq;
+using System.Runtime.InteropServices;
+using Microsoft.Win32;
+
+/**
+ * Methods for handling EFI variables.
+ */
+public class Efi {
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern UInt32 GetFirmwareEnvironmentVariableEx(string lpName, string lpGuid, [MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer, UInt32 nSize, out UInt32 pdwAttributes);
+
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern UInt32 SetFirmwareEnvironmentVariableEx(string lpName, string lpGuid, [MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer, UInt32 nSize, UInt32 pdwAttributes);
+
+	[DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
+	private static extern bool AdjustTokenPrivileges(IntPtr htoken, bool disable, ref TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen);
+
+	[DllImport("kernel32.dll", ExactSpelling = true)]
+	private static extern IntPtr GetCurrentProcess();
+
+	[DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]
+	private static extern bool OpenProcessToken(IntPtr h, int acc, out IntPtr phtok);
+
+	[DllImport("advapi32.dll", SetLastError = true)]
+	private static extern bool LookupPrivilegeValue(string host, string name, ref long pluid);
+
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern bool CloseHandle(IntPtr hObject);
+
+	[DllImport("kernel32.dll", SetLastError = true)]
+	private static extern UInt32 GetSystemFirmwareTable(UInt32 provider, UInt32 table, [MarshalAs(UnmanagedType.LPArray)] byte[] buffer, UInt32 len);
+
+	[StructLayout(LayoutKind.Sequential, Pack = 1)]
+	private struct TokPriv1Luid {
+		public int Count;
+		public long Luid;
+		public int Attr;
+	}
+
+	/**
+	 * Information about an EFI variable.
+	 */
+	public class Variable {
+		public string Name, Guid;
+		public UInt32 Attributes;
+		public byte[] Data;
+
+		/**
+		 * Convert to string.
+		 *
+		 * @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}'";
+		}
+	}
+
+	/**
+	 * Information about an EFI boot entry.
+	 */
+	public class BootEntryData {
+		public UInt32 Attributes;
+		public string Label;
+		public class DevicePathNode {
+			public byte Type, SubType;
+			public byte[] Data;
+			public DevicePathNode(byte[] data) {
+				Type = data[0];
+				SubType = data[1];
+				Data = data.Skip(4).ToArray();
+			}
+			public byte[] ToBytes() {
+				var len = Data.Length + 4;
+				return new byte[] { Type, SubType, (byte)(len & 0xff), (byte)(len >> 8) }.Concat(Data).ToArray();
+			}
+		}
+		public List<DevicePathNode> DevicePathNodes;
+		public byte[] Arguments;
+
+		public BootEntryData(byte[] data) {
+			Attributes = BitConverter.ToUInt32(data, 0);
+			var pathNodesLength = BitConverter.ToUInt16(data, 4);
+			Label = new string(BytesToUInt16s(data).Skip(3).TakeWhile(i => i != 0).Select(i => (char)i).ToArray());
+			var pos = 6 + 2 * (Label.Length + 1);
+			var pathNodesEnd = pos + pathNodesLength;
+			DevicePathNodes = new List<DevicePathNode>();
+			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()));
+				pos += len;
+			}
+			Arguments = data.Skip(pathNodesEnd).ToArray();
+		}
+		public byte[] ToBytes() {
+			return new byte[0]
+				.Concat(BitConverter.GetBytes((UInt32) Attributes))
+				.Concat(BitConverter.GetBytes((UInt16) DevicePathNodes.Sum(n => n.Data.Length + 4)))
+				.Concat(Encoding.Unicode.GetBytes(Label + "\0"))
+				.Concat(DevicePathNodes.SelectMany(n => n.ToBytes()))
+				.Concat(Arguments)
+				.ToArray();
+		}
+		public DevicePathNode FileNameNode {
+			get {
+				var d = DevicePathNodes;
+				return d.Count > 1 && d[d.Count - 1].Type == 0x7F && d[d.Count - 2].Type == 0x04 ? d[d.Count - 2] : null;
+			}
+		}
+		public bool HasFileName {
+			get {
+				return FileNameNode != null;
+			}
+		}
+		public string FileName {
+			get {
+				if (!HasFileName) {
+					return "";
+				}
+				return new string(Encoding.Unicode.GetChars(FileNameNode.Data).TakeWhile(c => c != '\0').ToArray());
+			}
+			set {
+				if (!HasFileName) {
+					throw new Exception("Logic error: Setting FileName on a bad boot entry.");
+				}
+				FileNameNode.Data = Encoding.Unicode.GetBytes(value + "\0");
+			}
+		}
+	}
+
+	/**
+	 * 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";
+
+	/**
+	 * Enable the privilege to access EFI variables.
+	 */
+	public static void EnablePrivilege() {
+		if (Directory.Exists(LinuxEfiDir)) {
+			var linuxEfiFile = $"{LinuxEfiDir}/BootOrder-8be4df61-93ca-11d2-aa0d-00e098032b8c";
+			if (File.Exists(linuxEfiFile)) {
+				using (FileStream fs = File.OpenWrite(linuxEfiFile)) {
+					// OpenWrite throws an exception on error.
+				}
+			}
+			return;
+		}
+
+		const int SE_PRIVILEGE_ENABLED = 0x00000002;
+		const int TOKEN_QUERY = 0x00000008;
+		const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
+		const string SE_SYSTEM_ENVIRONMENT_NAME = "SeSystemEnvironmentPrivilege";
+		IntPtr htoken = IntPtr.Zero;
+		if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, out htoken)) {
+			throw new Exception("EnablePrivilege: OpenProcessToken failed: " + Marshal.GetLastWin32Error());
+		}
+		try {
+			TokPriv1Luid tp;
+			tp.Count = 1;
+			tp.Luid = 0;
+			tp.Attr = SE_PRIVILEGE_ENABLED;
+			if (!LookupPrivilegeValue(null, SE_SYSTEM_ENVIRONMENT_NAME, ref tp.Luid)) {
+				throw new Exception("EnablePrivilege: LookupPrivilegeValue failed: " + Marshal.GetLastWin32Error());
+			}
+			if (!AdjustTokenPrivileges(htoken, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero)) {
+				throw new Exception("EnablePrivilege: AdjustTokenPrivileges failed: " + Marshal.GetLastWin32Error());
+			}
+		} finally {
+			CloseHandle(htoken);
+		}
+	}
+
+	/**
+	 * Get an EFI variable.
+	 *
+	 * @param name Name of the EFI variable.
+	 * @param guid GUID of the EFI variable.
+	 * @return Information about the EFI variable.
+	 */
+	private static Variable GetVariable(string name, string guid = EFI_GLOBAL_GUID) {
+		Variable result = new Variable();
+		result.Name = name;
+		result.Guid = guid;
+		result.Data = null;
+		result.Attributes = 0;
+
+		if (Directory.Exists(LinuxEfiDir)) {
+			var linuxEfiFile = $"{LinuxEfiDir}/{name}-{guid.Substring(1, guid.Length - 2)}";
+			if (File.Exists(linuxEfiFile)) {
+				var d = File.ReadAllBytes(linuxEfiFile);
+				result.Attributes = (UInt32)(d[0] + 0x100 * d[1] + 0x10000 * d[2] + 0x1000000 * d[3]);
+				result.Data = d.Skip(4).ToArray();
+			}
+			return result;
+		}
+
+		for (UInt32 i = 4096; i <= 1024*1024; i *= 2) {
+			byte[] buf = new byte[i];
+			UInt32 len = GetFirmwareEnvironmentVariableEx(name, guid, buf, (UInt32) buf.Length, out result.Attributes);
+			if (len == buf.Length) {
+				continue;
+			}
+			if (len > 0 || Marshal.GetLastWin32Error() == 0) {
+				result.Data = new byte[len];
+				Array.Copy(buf, 0, result.Data, 0, len);
+				return result;
+			}
+			switch (len != 0 ? 0 : Marshal.GetLastWin32Error()) {
+				case 203:
+					// Not found.
+					return result;
+				case 87:
+					throw new Exception("GetVariable: Invalid parameter");
+				case 1314:
+					throw new Exception("GetVariable: Privilege not held");
+				default:
+					throw new Exception("GetVariable: error " + Marshal.GetLastWin32Error());
+			}
+		}
+		throw new Exception("GetFirmwareEnvironmentVariable: too big data");
+	}
+
+	/**
+	 * Set an EFI variable.
+	 *
+	 * @param v Information of the variable.
+	 * @param dryRun Don't actually set the variable.
+	 */
+	private static void SetVariable(Variable v, bool dryRun = false) {
+		Setup.WriteLine($"Writing EFI variable {v.Name} (see log for details)");
+		Setup.Log($"Writing EFI variable: {v}");
+		if (dryRun) {
+			return;
+		}
+
+		if (Directory.Exists(LinuxEfiDir)) {
+			var linuxEfiFile = $"{LinuxEfiDir}/{v.Name}-{v.Guid.Substring(1, v.Guid.Length - 2)}";
+			var a = v.Attributes;
+			var b = new byte[] { (byte) a, (byte) (a >> 8), (byte) (a >> 16), (byte) (a >> 24) };
+			// FIXME: Just writing won't work: File.WriteAllBytes(linuxEfiFile, b.Concat(v.Data).ToArray());
+			Setup.WriteLine("FIXME: Can't yet write EFI variables in Linux.");
+			return;
+		}
+
+		UInt32 r = SetFirmwareEnvironmentVariableEx(v.Name, v.Guid, v.Data, (UInt32) v.Data.Length, v.Attributes);
+		if (r == 0) {
+			switch (Marshal.GetLastWin32Error()) {
+				case 87:
+					throw new Exception("SetVariable: Invalid parameter");
+				case 1314:
+					throw new Exception("SetVariable: Privilege not held");
+				default:
+					throw new Exception("SetVariable: error " + Marshal.GetLastWin32Error());
+			}
+		}
+	}
+
+	/**
+	 * Check if Secure Boot is enabled.
+	 *
+	 * @return 0 for disabled, 1 for enabled, other for unknown.
+	 */
+	public static int GetSecureBootStatus() {
+		// GetVariable("SecureBoot") reports always 1 (on Lenovo E335).
+		// Windows registry seems to work better, though.
+		try {
+			return (int) Registry.GetValue(
+				"HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\SecureBoot\\State",
+				"UEFISecureBootEnabled",
+				-1
+			);
+		} catch {
+			return -1;
+		}
+	}
+
+	/**
+	 * Check if it's possible to reboot to EFI setup.
+	 *
+	 * @return True, if it's possible to reboot to EFI setup.
+	 */
+	public static bool CanBootToFW() {
+		try {
+			Variable tmp = GetVariable("OsIndicationsSupported");
+			return tmp.Data != null && (tmp.Data[0] & 1) != 0;
+		} catch {
+			return false;
+		}
+	}
+
+	/**
+	 * Mark that the next reboot should go to EFI setup.
+	 */
+	public static void SetBootToFW() {
+		Variable tmp = GetVariable("OsIndications");
+		if (tmp.Data == null) {
+			tmp.Data = new byte[8];
+			tmp.Attributes = 7;
+		}
+		tmp.Data[0] |= 1;
+		SetVariable(tmp);
+	}
+
+	/**
+	 * Convert bytes into UInt16 values.
+	 *
+	 * @param bytes The byte array.
+	 * @return An enumeration of UInt16 values.
+	 */
+	public static IEnumerable<UInt16> BytesToUInt16s(byte[] bytes) {
+		// TODO: return bytes.Chunk(2).Select(b => (UInt16) (b[0] + 0x100 * b[1])).ToArray();
+		return Enumerable.Range(0, bytes.Length / 2).Select(i => (UInt16) (bytes[2 * i] + 0x100 * bytes[2 * i + 1]));
+	}
+
+	/**
+	 * Disable the said boot entry from BootOrder.
+	 *
+	 * @param label Label of the boot entry.
+	 * @param fileName File name of the boot entry.
+	 * @param dryRun Don't actually disable the entry.
+	 * @return True, if the entry was found in BootOrder.
+	 */
+	public static bool DisableBootEntry(string label, string fileName, bool dryRun = false) {
+		Variable bootOrder;
+		try {
+			bootOrder = GetVariable("BootOrder");
+		} catch {
+			return false;
+		}
+		if (bootOrder.Data == null) {
+			return false;
+		}
+		Setup.Log($"Read EFI variable: {bootOrder}");
+		var found = false;
+		var bootOrderInts = new List<UInt16>();
+		foreach (var num in BytesToUInt16s(bootOrder.Data)) {
+			var entry = GetVariable(String.Format("Boot{0:X04}", num));
+			if (entry.Data != null) {
+				var entryData = new BootEntryData(entry.Data);
+				if (entryData.Label == label && entryData.FileName == fileName) {
+					found = true;
+					continue;
+				}
+			}
+			bootOrderInts.Add(num);
+		}
+		if (found) {
+			bootOrder.Data = bootOrderInts.SelectMany(num => new byte[] { (byte)(num & 0xff), (byte)(num >> 8) }).ToArray();
+			SetVariable(bootOrder, dryRun);
+		}
+		return found;
+	}
+
+	/**
+	 * Create and enable the said boot entry from BootOrder.
+	 *
+	 * @param label Label of the boot entry.
+	 * @param fileName File name of the boot entry.
+	 * @param dryRun Don't actually create the entry.
+	 */
+	public static void MakeAndEnableBootEntry(string label, string fileName, bool dryRun = false) {
+		Variable msEntry = null, ownEntry = null;
+		UInt16 msNum = 0, ownNum = 0;
+
+		// Find a free entry and the MS bootloader entry.
+		Variable bootOrder = null;
+		try {
+			bootOrder = GetVariable("BootOrder");
+		} catch {
+			if (dryRun) {
+				return;
+			}
+		}
+		if (bootOrder == null || bootOrder.Data == null) {
+			throw new Exception("MakeBootEntry: Could not read BootOrder. Maybe your computer is defective.");
+		}
+		var bootCurrent = GetVariable("BootCurrent");
+		if (bootCurrent.Data == null) {
+			throw new Exception("MakeBootEntry: Could not read BootCurrent. Maybe your computer is defective.");
+		}
+		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))) {
+			var entry = GetVariable(String.Format("Boot{0:X04}", num));
+			if (entry.Data == null) {
+				if (ownEntry == null) {
+					ownNum = num;
+					ownEntry = entry;
+				}
+			} else {
+				var entryData = new BootEntryData(entry.Data);
+				if (!entryData.HasFileName) {
+					continue;
+				}
+				if (entryData.Label == label && entryData.FileName == fileName) {
+					ownNum = num;
+					ownEntry = entry;
+				}
+				if (msEntry == null && entryData.FileName.StartsWith("\\EFI\\Microsoft\\Boot\\bootmgfw.efi", StringComparison.OrdinalIgnoreCase)) {
+					msNum = num;
+					msEntry = entry;
+				}
+			}
+			if (ownEntry != null && msEntry != null) {
+				break;
+			}
+		}
+		if (ownEntry == null) {
+			throw new Exception("MakeBootEntry: Boot entry list is full.");
+		} else if (msEntry == null) {
+			throw new Exception("MakeBootEntry: Windows Boot Manager not found.");
+		} else {
+			Setup.Log($"Read EFI variable: {msEntry}");
+			// Make a new boot entry using the MS entry as a starting point.
+			var entryData = new BootEntryData(msEntry.Data);
+			entryData.Arguments = Encoding.UTF8.GetBytes(label + "\0");
+			entryData.Attributes = 1; // LOAD_OPTION_ACTIVE
+			entryData.Label = label;
+			entryData.FileName = fileName;
+			ownEntry.Attributes = 7; // EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS
+			ownEntry.Data = entryData.ToBytes();
+			SetVariable(ownEntry, dryRun);
+		}
+
+		var msPos = bootOrderInts.IndexOf(msNum);
+		var ownPos = bootOrderInts.IndexOf(ownNum);
+		var mustAdd = ownPos == -1;
+		var mustMove = 0 <= msPos && msPos <= ownPos;
+		if (mustAdd || mustMove) {
+			if (mustMove) {
+				bootOrderInts.RemoveAt(ownPos);
+			}
+			bootOrderInts.Insert(msPos < 0 ? 0 : msPos, ownNum);
+			bootOrder.Data = bootOrderInts.SelectMany(num => new byte[] { (byte)(num & 0xff), (byte)(num >> 8) }).ToArray();
+			SetVariable(bootOrder, dryRun);
+		}
+	}
+
+	/**
+	 * Log the boot entries.
+	 */
+	public static void LogBootEntries() {
+		try {
+			var bootOrder = GetVariable("BootOrder");
+			var bootCurrent = GetVariable("BootCurrent");
+			Setup.Log($"LogBootOrder: {bootOrder}");
+			Setup.Log($"LogBootOrder: {bootCurrent}");
+			var bootOrderInts = new List<UInt16>(BytesToUInt16s(bootOrder.Data));
+			// Windows can't enumerate EFI variables, and trying them all is too slow.
+			// BootOrder + BootCurrent + the first 0xff entries should be enough.
+			foreach (var num in BytesToUInt16s(bootCurrent.Data).Concat(bootOrderInts).Concat(Enumerable.Range(0, 0xff).Select(i => (UInt16) i))) {
+				var entry = GetVariable(String.Format("Boot{0:X04}", num));
+				if (entry.Data != null) {
+					Setup.Log($"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);
+			return new string(BytesToUInt16s(log.Data).Select(i => (char)i).ToArray());
+		} catch (Exception e) {
+			return $"Log not found: {e.ToString()}";
+		}
+	}
+
+	/**
+	 * Log the BGRT table (for debugging).
+	 */
+	public static void LogBGRT() {
+		try {
+			const UInt32 acpiBE = 0x41435049, bgrtLE = 0x54524742;
+			UInt32 size = GetSystemFirmwareTable(acpiBE, bgrtLE, null, 0);
+			byte[] buf = new byte[size];
+			var ret = GetSystemFirmwareTable(acpiBE, bgrtLE, buf, size);
+			if (ret == size) {
+				var hex = BitConverter.ToString(buf).Replace("-", " ");
+				Setup.Log($"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 failed: {e}");
+		}
+	}
+}

src/Esp.cs

@@ -0,0 +1,129 @@
+using System;
+using System.IO;
+using System.Text.RegularExpressions;
+
+/**
+ * EFI System Partition mounter.
+ */
+public sealed class Esp {
+	/** The singleton instance of this class, if ESP is mounted. */
+	private static Esp MountInstance;
+
+	/** EFI System Partition location. */
+	public static string Location { get; private set; }
+
+	/** MS boot loader path on ESP. */
+	public static string MsLoaderPath {
+		get {
+			return Path.Combine(new string[] { Location, "EFI", "Microsoft", "Boot", "bootmgfw.efi"});
+		}
+	}
+
+	/**
+	 * Constructor: do nothing.
+	 */
+	private Esp() {
+	}
+
+	/**
+	 * Destructor: unmount.
+	 */
+	~Esp() {
+		if (this == MountInstance) {
+			Unmount();
+		}
+	}
+
+	/**
+	 * Try to find ESP at a path.
+	 *
+	 * @param tryPath The new path to try.
+	 * @param requireMsLoader Look for MS boot loader specifically?
+	 * @return true if the path was given and seems valid, false otherwise.
+	 */
+	public static bool TryPath(string tryPath, bool requireMsLoader = true) {
+		if (MountInstance != null && Location != null) {
+			Unmount();
+		}
+		Location = tryPath;
+		if (Location != null && Location != "") {
+			if (File.Exists(MsLoaderPath)) {
+				Setup.Log($"Esp.TryPath: {Location} has MS boot loader");
+				return true;
+			}
+			if (Directory.Exists(Path.Combine(Location, "EFI"))) {
+				Setup.Log($"Esp.TryPath: {Location} has EFI directory but no loader");
+				if (!requireMsLoader) {
+					return true;
+				}
+			}
+		}
+		Location = null;
+		return false;
+	}
+
+	/**
+	 * Find the EFI System Partition, if it's already mounted.
+	 *
+	 * @return true if the drive was found.
+	 */
+	public static bool Find() {
+		if (MountInstance != null) {
+			return true;
+		}
+		Setup.Log("Esp.Find()");
+		try {
+			// Match "The EFI System Partition is mounted at E:\" with some language support.
+			var re = new Regex(" EFI[^\n]*(?:\n[ \t]*)?([A-Z]:\\\\)");
+			var m = re.Match(Setup.Execute("mountvol", "", false));
+			if (m.Success && TryPath(m.Groups[1].Captures[0].Value)) {
+				return true;
+			}
+			Setup.Log("Esp.Find: no match");
+		} catch (Exception e) {
+			Setup.Log($"Esp.Find: {e.ToString()}");
+		}
+		for (char c = 'A'; c <= 'Z'; ++c) {
+			if (TryPath(c + ":\\")) {
+				Setup.Log($"Esp.Find: found {c}");
+				return true;
+			}
+		}
+		Setup.Log("Esp.Find: not found");
+		return false;
+	}
+
+	/**
+	 * Mount the EFI System Partition.
+	 *
+	 * @return true if the drive was mounted, false otherwise.
+	 */
+	public static bool Mount() {
+		if (MountInstance != null) {
+			return true;
+		}
+		for (char c = 'A'; c <= 'Z'; ++c) {
+			Setup.Log($"Esp.Mount: {c}");
+			if (Setup.Execute("mountvol", c + ": /S", true) != null) {
+				MountInstance = new Esp();
+				if (TryPath(c + ":\\", false)) {
+					return true;
+				} else {
+					throw new Exception("Mounted ESP at " + c + ":\\ but it seems to be invalid!");
+				}
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Unmount the EFI System Partition, if necessary.
+	 */
+	private static void Unmount() {
+		if (MountInstance != null) {
+			Setup.Execute("mountvol", Location + " /D", true);
+			Location = null;
+			MountInstance = null;
+		}
+	}
+}

src/config.c

@@ -8,7 +8,7 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 	UINTN data_bytes = 0;
 	data = LoadFileWithPadding(root_dir, path, &data_bytes, 4);
 	if (!data) {
-		Print(L"HackBGRT: Failed to load configuration (%s)!\n", path);
+		Log(1, L"HackBGRT: Failed to load configuration (%s)!\n", path);
 		return FALSE;
 	}
 	CHAR16* str;
@@ -70,35 +70,35 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 	return TRUE;
 }
 
-static void SetBMPWithRandom(struct HackBGRT_config* config, int weight, enum HackBGRT_action action, int x, int y, const CHAR16* path) {
+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, path %s, random = %08x, limit = %08x\n", weight, action, x, y, path, random, limit);
-	}
+	Log(config->debug, L"HackBGRT: n=%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) {
 		config->action = action;
 		config->image_path = path;
+		config->orientation = o;
 		config->image_x = x;
 		config->image_y = y;
 	}
 }
 
 static int ParseCoordinate(const CHAR16* str, enum HackBGRT_action action) {
-	if (str && L'0' <= str[0] && str[0] <= L'9') {
-		return Atoi(str);
+	if (str && ((L'0' <= str[0] && str[0] <= L'9') || str[0] == L'-')) {
+		return str[0] == L'-' ? -(int)Atoi(str+1) : (int)Atoi(str);
 	}
-	if ((str && StrnCmp(str, L"native", 6) == 0) || action == HackBGRT_KEEP) {
-		return HackBGRT_coord_native;
+	if ((str && StrnCmp(str, L"keep", 4) == 0) || action == HackBGRT_KEEP) {
+		return HackBGRT_coord_keep;
 	}
-	return HackBGRT_coord_auto;
+	return 0;
 }
 
 static void ReadConfigImage(struct HackBGRT_config* config, const CHAR16* line) {
 	const CHAR16* n = StrStrAfter(line, L"n=");
 	const CHAR16* x = StrStrAfter(line, L"x=");
 	const CHAR16* y = StrStrAfter(line, L"y=");
+	const CHAR16* o = StrStrAfter(line, L"o=");
 	const CHAR16* f = StrStrAfter(line, L"path=");
 	enum HackBGRT_action action = HackBGRT_KEEP;
 	if (f) {
@@ -110,11 +110,14 @@ 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"HackBGRT: Invalid image line: %s\n", line);
 		return;
 	}
 	int weight = n && (!f || n < f) ? Atoi(n) : 1;
-	SetBMPWithRandom(config, weight, action, ParseCoordinate(x, action), ParseCoordinate(y, action), f);
+	int x_val = ParseCoordinate(x, action);
+	int y_val = ParseCoordinate(y, action);
+	int o_val = o ? ParseCoordinate(o, action) : HackBGRT_coord_keep;
+	SetBMPWithRandom(config, weight, action, x_val, y_val, o_val, f);
 }
 
 static void ReadConfigResolution(struct HackBGRT_config* config, const CHAR16* line) {
@@ -124,7 +127,7 @@ 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"HackBGRT: Invalid resolution line: %s\n", line);
 	}
 }
 
@@ -138,6 +141,10 @@ 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;
@@ -154,5 +161,5 @@ void ReadConfigLine(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir, co
 		ReadConfigResolution(config, line + 11);
 		return;
 	}
-	Print(L"Unknown configuration directive: %s\n", line);
+	Log(1, L"Unknown configuration directive: %s\n", line);
 }

src/config.h

@@ -14,22 +14,24 @@ enum HackBGRT_action {
  * @see struct HackBGRT_config
  */
 enum HackBGRT_coordinate {
-	HackBGRT_coord_auto = 0x10000001,
-	HackBGRT_coord_native = 0x10000002
+	HackBGRT_coord_keep = -1000000001
 };
 
 /**
  * The configuration.
  */
 struct HackBGRT_config {
-	int debug;
+	int debug, log;
 	enum HackBGRT_action action;
 	const CHAR16* image_path;
 	int image_x;
 	int image_y;
 	int image_weight_sum;
+	int orientation;
 	int resolution_x;
 	int resolution_y;
+	int old_resolution_x;
+	int old_resolution_y;
 	const CHAR16* boot_path;
 };
 

src/main.c

@@ -6,20 +6,20 @@
 #include "util.h"
 
 /**
- * The Print function signature.
+ * The version.
  */
-typedef UINTN print_t(IN CHAR16 *fmt, ...);
-
-/**
- * The function for debug printing; either Print or NullPrint.
- */
-print_t* Debug = NullPrint;
+#ifdef GIT_DESCRIBE_W
+	const CHAR16 version[] = GIT_DESCRIBE_W;
+#else
+	const CHAR16 version[] = L"unknown; not an official release?";
+#endif
 
 /**
  * The configuration.
  */
 static struct HackBGRT_config config = {
-	.action = HackBGRT_KEEP
+	.log = 1,
+	.action = HackBGRT_KEEP,
 };
 
 /**
@@ -43,16 +43,18 @@ static EFI_GRAPHICS_OUTPUT_PROTOCOL* GOP(void) {
 static void SetResolution(int w, int h) {
 	EFI_GRAPHICS_OUTPUT_PROTOCOL* gop = GOP();
 	if (!gop) {
-		Debug(L"GOP not found!\n");
+		config.old_resolution_x = config.resolution_x = 0;
+		config.old_resolution_y = config.resolution_y = 0;
+		Log(config.debug, L"GOP not found!\n");
 		return;
 	}
 	UINTN best_i = gop->Mode->Mode;
-	int best_w = gop->Mode->Info->HorizontalResolution;
-	int best_h = gop->Mode->Info->VerticalResolution;
-	w = (w <= 0 ? w < 0 ? best_w : 0x7fffffff : w);
-	h = (h <= 0 ? h < 0 ? best_h : 0x7fffffff : h);
+	int best_w = config.old_resolution_x = gop->Mode->Info->HorizontalResolution;
+	int best_h = config.old_resolution_y = gop->Mode->Info->VerticalResolution;
+	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;
 
@@ -85,30 +87,14 @@ 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) {
 		gop->SetMode(gop, best_i);
 	}
 }
 
-/**
- * Select the correct coordinate (manual, automatic, native)
- *
- * @param value The configured coordinate value; has special values for automatic and native.
- * @param automatic The automatically calculated alternative.
- * @param native The original coordinate.
- * @see enum HackBGRT_coordinate
- */
-static int SelectCoordinate(int value, int automatic, int native) {
-	if (value == HackBGRT_coord_auto) {
-		return automatic;
-	}
-	if (value == HackBGRT_coord_native) {
-		return native;
-	}
-	return value;
-}
-
 /**
  * Create a new XSDT with the given number of entries.
  *
@@ -121,7 +107,7 @@ 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"HackBGRT: Failed to allocate memory for XSDT.\n");
 		return 0;
 	}
 	ZeroMem(xsdt, xsdt_len);
@@ -153,17 +139,17 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
 		if (CompareMem(rsdp->signature, "RSD PTR ", 8) != 0 || rsdp->revision < 2 || !VerifyAcpiRsdp2Checksums(rsdp)) {
 			continue;
 		}
-		Debug(L"RSDP: revision = %d, OEM ID = %s\n", 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: OEM ID = %s, entry count = %d\n", 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++) {
@@ -171,16 +157,16 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
 			if (CompareMem(entry->signature, "BGRT", 4) != 0) {
 				continue;
 			}
-			Debug(L" - ACPI table: %s, revision = %d, OEM ID = %s\n", 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];
 					}
@@ -190,13 +176,13 @@ 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;
@@ -208,6 +194,44 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
 	return bgrt;
 }
 
+/**
+ * Generate a BMP with the given size and color.
+ *
+ * @param w The width.
+ * @param h The height.
+ * @param r The red component.
+ * @param g The green component.
+ * @param b The blue component.
+ * @return The generated BMP, or 0 on failure.
+ */
+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) {
+		Log(1, L"HackBGRT: Failed to allocate a blank BMP!\n");
+		BS->Stall(1000000);
+		return 0;
+	}
+	*bmp = (BMP) {
+		.magic_BM = { 'B', 'M' },
+		.file_size = 54 + w * h * 4,
+		.pixel_data_offset = 54,
+		.dib_header_size = 40,
+		.width = w,
+		.height = h,
+		.planes = 1,
+		.bpp = 32,
+	};
+	UINT8* data = (UINT8*) bmp + bmp->pixel_data_offset;
+	for (int y = 0; y < h; ++y) for (int x = 0; x < w; ++x) {
+		*data++ = b;
+		*data++ = g;
+		*data++ = r;
+		*data++ = 0;
+	}
+	return bmp;
+}
+
 /**
  * Load a bitmap or generate a black one.
  *
@@ -216,32 +240,51 @@ static ACPI_BGRT* HandleAcpiTables(enum HackBGRT_action action, ACPI_BGRT* bgrt)
  * @return The loaded BMP, or 0 if not available.
  */
 static BMP* LoadBMP(EFI_FILE_HANDLE root_dir, const CHAR16* path) {
-	BMP* bmp = 0;
 	if (!path) {
-		BS->AllocatePool(EfiBootServicesData, 58, (void**) &bmp);
-		if (!bmp) {
-			Print(L"HackBGRT: Failed to allocate a blank BMP!\n");
-			BS->Stall(1000000);
-			return 0;
+		return MakeBMP(1, 1, 0, 0, 0); // empty path = black image
 	}
+	Log(config.debug, L"HackBGRT: Loading %s.\n", path);
+	UINTN size = 0;
+	BMP* bmp = LoadFile(root_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) {
+			return bmp;
+		}
+		FreePool(bmp);
+		Log(1, L"HackBGRT: Invalid BMP (%s)!\n", path);
+	} else {
+		Log(1, L"HackBGRT: Failed to load BMP (%s)!\n", path);
+	}
+	BS->Stall(1000000);
+	return MakeBMP(16, 16, 255, 0, 0); // error = red image
+}
+
+/**
+ * Crop a BMP to the given size.
+ *
+ * @param bmp The BMP to crop.
+ * @param w The maximum width.
+ * @param h The maximum height.
+ */
+static void CropBMP(BMP* bmp, int w, int h) {
+	const int old_pitch = -(-(bmp->width * (bmp->bpp / 8)) & ~3);
+	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(
-			bmp,
-			"\x42\x4d\x3a\x00\x00\x00\x00\x00\x00\x00\x36\x00\x00\x00\x28\x00"
-			"\x00\x00\x01\x00\x00\x00\x01\x00\x00\x00\x01\x00\x18\x00\x00\x00"
-			"\x00\x00\x04\x00\x00\x00\x13\x0b\x00\x00\x13\x0b\x00\x00\x00\x00"
-			"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
-			58
+				(UINT8*) bmp + bmp->pixel_data_offset + i * new_pitch,
+				(UINT8*) bmp + bmp->pixel_data_offset + i * old_pitch,
+				new_pitch
 			);
-		return bmp;
 		}
-	Debug(L"HackBGRT: Loading %s.\n", path);
-	bmp = LoadFile(root_dir, path, 0);
-	if (!bmp) {
-		Print(L"HackBGRT: Failed to load BMP (%s)!\n", path);
-		BS->Stall(1000000);
-		return 0;
 	}
-	return bmp;
+	bmp->file_size = bmp->pixel_data_offset + bmp->height * new_pitch;
 }
 
 /**
@@ -259,14 +302,15 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 	// KEEP/REPLACE: first get the old BGRT entry.
 	ACPI_BGRT* bgrt = HandleAcpiTables(HackBGRT_KEEP, 0);
 
-	// Get the old BMP and position, if possible.
-	BMP* old_bmp = 0;
-	int old_x = 0, old_y = 0;
-	if (bgrt && VerifyAcpiSdtChecksum(bgrt)) {
-		old_bmp = (BMP*) (UINTN) bgrt->image_address;
-		old_x = bgrt->image_offset_x;
-		old_y = bgrt->image_offset_y;
-	}
+	// Get the old BMP and position (relative to screen center), if possible.
+	const int old_valid = bgrt && VerifyAcpiSdtChecksum(bgrt);
+	BMP* old_bmp = old_valid ? (BMP*) (UINTN) bgrt->image_address : 0;
+	const int old_orientation = old_valid ? ((bgrt->status >> 1) & 3) : 0;
+	const int old_swap = old_orientation & 1;
+	const int old_reso_x = old_swap ? config.old_resolution_y : config.old_resolution_x;
+	const int old_reso_y = old_swap ? config.old_resolution_x : config.old_resolution_y;
+	const int old_x = old_bmp ? bgrt->image_offset_x + (old_bmp->width - old_reso_x) / 2 : 0;
+	const int old_y = old_bmp ? bgrt->image_offset_y + (old_bmp->height - old_reso_y) / 2 : 0;
 
 	// Missing BGRT?
 	if (!bgrt) {
@@ -277,17 +321,24 @@ 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"HackBGRT: Failed to allocate memory for BGRT.\n");
 			return;
 		}
 	}
 
-	// Clear the BGRT.
-	const char data[0x38] =
-		"BGRT" "\x38\x00\x00\x00" "\x00" "\xd6" "Mtblx*" "HackBGRT"
-		"\x20\x17\x00\x00" "PTL " "\x02\x00\x00\x00"
-		"\x01\x00" "\x00" "\x00";
-	CopyMem(bgrt, data, sizeof(data));
+	*bgrt = (ACPI_BGRT) {
+		.header = {
+			.signature = "BGRT",
+			.length = sizeof(*bgrt),
+			.revision = 1,
+			.oem_id = "Mtblx*",
+			.oem_table_id = "HackBGRT",
+			.oem_revision = 1,
+			.asl_compiler_id = *(const UINT32*) "None",
+			.asl_compiler_revision = 1,
+		},
+		.version = 1,
+	};
 
 	// Get the image (either old or new).
 	BMP* new_bmp = old_bmp;
@@ -301,37 +352,62 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 		return;
 	}
 
+	// Crop the image to screen.
+	CropBMP(new_bmp, config.resolution_x, config.resolution_y);
+
+	// Set the image address and orientation.
 	bgrt->image_address = (UINTN) new_bmp;
+	const int new_orientation = config.orientation == HackBGRT_coord_keep ? old_orientation : ((config.orientation / 90) & 3);
+	bgrt->status = new_orientation << 1;
 
-	// Calculate the automatically centered position for the image.
-	int auto_x = 0, auto_y = 0;
-	if (GOP()) {
-		auto_x = max(0, ((int)GOP()->Mode->Info->HorizontalResolution - (int)new_bmp->width) / 2);
-		auto_y = max(0, ((int)GOP()->Mode->Info->VerticalResolution * 2/3 - (int)new_bmp->height) / 2);
-	} else if (old_bmp) {
-		auto_x = max(0, old_x + ((int)old_bmp->width - (int)new_bmp->width) / 2);
-		auto_y = max(0, old_y + ((int)old_bmp->height - (int)new_bmp->height) / 2);
-	}
+	// New center coordinates.
+	const int new_x = config.image_x == HackBGRT_coord_keep ? old_x : config.image_x;
+	const int new_y = config.image_y == HackBGRT_coord_keep ? old_y : config.image_y;
+	const int new_swap = new_orientation & 1;
+	const int new_reso_x = new_swap ? config.resolution_y : config.resolution_x;
+	const int new_reso_y = new_swap ? config.resolution_x : config.resolution_y;
 
-	// Set the position (manual, automatic, original).
-	bgrt->image_offset_x = SelectCoordinate(config.image_x, auto_x, old_x);
-	bgrt->image_offset_y = SelectCoordinate(config.image_y, auto_y, old_y);
-	Debug(L"HackBGRT: BMP at (%d, %d).\n", (int) bgrt->image_offset_x, (int) bgrt->image_offset_y);
+	// Calculate absolute position.
+	const int max_x = new_reso_x - new_bmp->width;
+	const int max_y = new_reso_y - new_bmp->height;
+	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));
+
+	Log(config.debug,
+		L"HackBGRT: 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
+	);
 
 	// Store this BGRT in the ACPI tables.
 	SetAcpiSdtChecksum(bgrt);
 	HandleAcpiTables(HackBGRT_REPLACE, bgrt);
 }
 
+/**
+ * Load an application.
+ */
+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;
+	Log(config.debug, L"HackBGRT: Loading application %s.\n", path);
+	if (EFI_ERROR(BS->LoadImage(0, image_handle, boot_dp, 0, 0, &result))) {
+		Log(config.debug || print_failure, L"HackBGRT: Failed to load application %s.\n", path);
+	}
+	return result;
+}
+
 /**
  * The main program.
  */
 EFI_STATUS EFIAPI EfiMain(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *ST_) {
 	InitializeLib(image_handle, ST_);
+	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");
+		Log(config.debug, L"HackBGRT: LOADED_IMAGE_PROTOCOL failed.\n");
 		goto fail;
 	}
 
@@ -343,66 +419,73 @@ EFI_STATUS EFIAPI EfiMain(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE *ST_) {
 	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);
+			Log(1, L"HackBGRT: No config, no command line!\n", config_path);
 			goto fail;
 		}
 	}
 	for (int i = 1; i < argc; ++i) {
 		ReadConfigLine(&config, root_dir, argv[i]);
 	}
-	Debug = config.debug ? Print : NullPrint;
+	if (config.debug) {
+		Print(L"HackBGRT version: %s\n", version);
+	}
 
 	SetResolution(config.resolution_x, config.resolution_y);
 	HackBgrt(root_dir);
 
 	EFI_HANDLE next_image_handle = 0;
-	if (!config.boot_path) {
-		Print(L"HackBGRT: Boot path not specified.\n");
-	} else {
-		Debug(L"HackBGRT: Loading application %s.\n", config.boot_path);
-		EFI_DEVICE_PATH* boot_dp = FileDevicePath(image->DeviceHandle, (CHAR16*) config.boot_path);
-		if (EFI_ERROR(BS->LoadImage(0, image_handle, boot_dp, 0, 0, &next_image_handle))) {
-			Print(L"HackBGRT: Failed to load application %s.\n", config.boot_path);
-		}
+	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(1, image_handle, image, config.boot_path);
+		try_ms_quietly = 0;
 	}
 	if (!next_image_handle) {
-		static CHAR16 default_boot_path[] = L"\\EFI\\HackBGRT\\bootmgfw-original.efi";
-		Debug(L"HackBGRT: Loading application %s.\n", default_boot_path);
-		EFI_DEVICE_PATH* boot_dp = FileDevicePath(image->DeviceHandle, default_boot_path);
-		if (EFI_ERROR(BS->LoadImage(0, image_handle, boot_dp, 0, 0, &next_image_handle))) {
-			Print(L"HackBGRT: Also failed to load application %s.\n", default_boot_path);
+		config.boot_path = backup_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(!try_ms_quietly, image_handle, image, config.boot_path);
+			if (!next_image_handle) {
 				goto fail;
 			}
-		Print(L"HackBGRT: Reverting to %s.\n", default_boot_path);
-		Print(L"Press escape to cancel, any other key to boot.\n");
-		if (ReadKey().ScanCode == SCAN_ESC) {
+		}
+		if (try_ms_quietly) {
+			goto ready_to_boot;
+		}
+		Log(1, 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 (ReadKey(15000).ScanCode == SCAN_ESC) {
 			goto fail;
 		}
-		config.boot_path = default_boot_path;
-	}
-	if (config.debug) {
-		Print(L"HackBGRT: Ready to boot.\nPress escape to cancel, any other key to boot.\n");
-		if (ReadKey().ScanCode == SCAN_ESC) {
+	} else ready_to_boot: if (config.debug) {
+		Print(L"HackBGRT: Ready to boot.\n");
+		Print(L"If all goes well, you can set debug=0 and log=0 in config.txt.\n");
+		Print(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"HackBGRT: Failed to start %s.\n", config.boot_path);
 		goto fail;
 	}
-	Print(L"HackBGRT: Started %s. Why are we still here?!\n", config.boot_path);
+	Log(1, 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);
 	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 to exit.\n");
-		ReadKey();
+		Log(1, L"HackBGRT has failed.\n");
+		Print(L"Dumping log:\n\n");
+		DumpLog();
+		Print(L"If you can't boot into Windows, get install/recovery disk to fix your boot.\n");
+		Print(L"Press any key (or wait 15 seconds) to exit.\n");
+		ReadKey(15000);
 		return 1;
 	}
 }

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"
+;

src/types.h

@@ -52,6 +52,12 @@ typedef struct {
 	UINT32 height;
 	UINT16 planes;
 	UINT16 bpp;
+	UINT32 compression;
+	UINT32 image_size;
+	UINT32 x_pixels_per_meter;
+	UINT32 y_pixels_per_meter;
+	UINT32 colors_used;
+	UINT32 important_colors;
 } BMP;
 
 /**

src/util.c

@@ -14,8 +14,31 @@ const CHAR16* TmpStr(CHAR8 *src, int length) {
 	return dest;
 }
 
-UINTN NullPrint(IN CHAR16 *fmt, ...) {
-	return 0;
+#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 print, IN CONST CHAR16 *fmt, ...) {
+	va_list args;
+	CHAR16 buf[256];
+	va_start(args, fmt);
+	VSPrint(buf, sizeof(buf), fmt, args); // size is in bytes, not CHAR16s
+	va_end(args);
+	if (print) {
+		Print(L"%s", buf);
+	}
+	StrnCat(log_buffer, buf, log_buffer_size - StrLen(log_buffer) - 1);
+	LibSetVariable(LogVarName, &LogVarGuid, StrLen(log_buffer) * 2, log_buffer);
+}
+
+void DumpLog(void) {
+	Print(L"%s", log_buffer);
+}
+
+void ClearLogVariable(void) {
+	LibDeleteVariable(LogVarName, &LogVarGuid);
 }
 
 const CHAR16* TrimLeft(const CHAR16* s) {
@@ -68,14 +91,15 @@ void RandomSeedAuto(void) {
 	RandomSeed(a, b), Random(), Random();
 }
 
-void WaitKey(void) {
+EFI_STATUS WaitKey(UINT64 timeout_ms) {
 	ST->ConIn->Reset(ST->ConIn, FALSE);
-	WaitForSingleEvent(ST->ConIn->WaitForKey, 0);
+	const int ms_to_100ns = 10000;
+	return WaitForSingleEvent(ST->ConIn->WaitForKey, timeout_ms * ms_to_100ns);
 }
 
-EFI_INPUT_KEY ReadKey(void) {
-	WaitKey();
+EFI_INPUT_KEY ReadKey(UINT64 timeout_ms) {
 	EFI_INPUT_KEY key = {0};
+	WaitKey(timeout_ms);
 	ST->ConIn->ReadKeyStroke(ST->ConIn, &key);
 	return key;
 }

src/util.h

@@ -14,7 +14,17 @@ extern const CHAR16* TmpStr(CHAR8 *src, int length);
 /**
  * Empty function that has the same signature as Print.
  */
-extern UINTN NullPrint(IN CHAR16 *fmt, ...);
+extern void Log(int print, 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.
@@ -82,15 +92,18 @@ extern void RandomSeedAuto(void);
 
 /**
  * Wait for a key press. It will still remain in the buffer.
+ *
+ * @param timeout_ms The timeout in milliseconds, or 0 for no timeout.
  */
-extern void WaitKey(void);
+extern EFI_STATUS WaitKey(UINT64 timeout_ms);
 
 /**
  * Wait for a key press and read it.
  *
+ * @param timeout_ms The timeout in milliseconds, or 0 for no timeout.
  * @return The pressed key.
  */
-extern EFI_INPUT_KEY ReadKey(void);
+extern EFI_INPUT_KEY ReadKey(UINT64 timeout_ms);
 
 /**
  * Load a file, allocate some extra bytes as well.