Update ci

.github/workflows/build.yml

@@ -1,23 +1,45 @@
 name: Build UEFI Application
+
 on:
   push:
     branches: [master]
   pull_request:
     branches: [master]
+
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout code
       uses: actions/checkout@v2
+
     - name: Set up environment
       run: |
         sudo apt-get update
-        sudo apt-get install -y build-essential gcc gnu-efi mtools grub-efi-amd64-bin
+        sudo apt-get install -y build-essential gcc gnu-efi mtools parted ovmf qemu-system-x86
+
+    - name: Determine system paths
+      id: system-paths
+      run: |
+        echo "INCLUDE_DIRS=$(dirname $(find /usr/include -name efi.h | head -n 1))" >> $GITHUB_OUTPUT
+        echo "LD_OBJ=$(find /usr/lib -name crt0-efi-x86_64.o | head -n 1)" >> $GITHUB_OUTPUT
+        echo "EFI_LDS=$(find /usr/lib -name elf_x86_64_efi.lds | head -n 1)" >> $GITHUB_OUTPUT
+        echo "BIOS_FD=$(find /usr/share -name OVMF.fd | head -n 1)" >> $GITHUB_OUTPUT
+
     - name: Build UEFI application
-      run: make all
+      run: |
+        make \
+          INCLUDE_DIRS="${{ steps.system-paths.outputs.INCLUDE_DIRS }}" \
+          LD_OBJ="${{ steps.system-paths.outputs.LD_OBJ }}" \
+          EFI_LDS="${{ steps.system-paths.outputs.EFI_LDS }}" \
+          BIOS_FD="${{ steps.system-paths.outputs.BIOS_FD }}"
     - name: Archive build artifacts
       uses: actions/upload-artifact@v2
       with:
         name: reboot-efi
         path: reboot.efi
+    - name: Archive build artifacts
+      uses: actions/upload-artifact@v2
+      with:
+        name: reboot-img
+        path: reboot.img

Makefile

@@ -7,14 +7,13 @@ EFI_LDS ?= /usr/lib/elf_x86_64_efi.lds
 BIOS_FD ?= /usr/share/OVMF/FV/OVMF.fd
 DISK_BLOCK_COUNT ?= 204800
 DISK_BLOCK_SIZE_BYTES ?= 512
-DISK_SIZE_MiB := $(shell echo $$(($(DISK_BLOCK_COUNT) * $(DISK_BLOCK_SIZE_BYTES) / 1024)))
 
 CFLAGS := -c -fno-stack-protector -fpic -fshort-wchar -mno-red-zone -DEFI_FUNCTION_WRAPPER $(addprefix -I,$(INCLUDE_DIRS))
 LDFLAGS := -nostdlib -znocombreloc -T $(EFI_LDS) -shared -Bsymbolic -L ./ -l:libgnuefi.a -l:libefi.a
 QEMUFLAGS := -bios $(BIOS_FD) -nographic -serial mon:stdio 
 
 .PHONY: all
-all: reboot.efi
+all: reboot.efi reboot.img
 
 .PHONY: run
 run: reboot.img

README.md

@@ -1,3 +1,84 @@
-# re-bootloader
+# Re-Bootloader
 
-UEFI bootloader, which instantly reboots.
+This project implements a simple UEFI bootloader that immediately reboots the system.
+
+Useful as a fall-back disk install in case machines that rely on PXE cannot be configured to auto-retry.
+
+## Dependencies
+
+This project requires the following tools and libraries:
+
+- GCC
+- GNU-EFI
+- Parted
+- mtools
+- QEMU + OVMF (for running locally)
+
+### Installing Dependencies
+
+#### Ubuntu/Debian:
+
+```sh
+sudo apt-get install gcc gnu-efi parted mtools qemu-system-x86 ovmf
+```
+
+#### Fedora/CentOS:
+
+```sh
+sudo dnf install gcc gnu-efi parted mtools qemu-system-x86 ovmf
+```
+
+#### Arch Linux:
+
+```sh
+sudo pacman -S gcc gnu-efi parted mtools qemu ovmf
+```
+
+## Building
+
+To build the project, simply run:
+
+```sh
+make
+```
+
+This will create `reboot.efi` (the UEFI application) and `reboot.img` (a disk image containing the bootloader).
+
+## Running
+
+To test the bootloader in QEMU, run:
+
+```
+make run
+```
+
+## Customization
+
+The Makefile supports several variables that can be overridden:
+
+- `INCLUDE_DIRS`: Directories to search for header files (default: `/usr/lib`)
+- `LD_OBJ`: Path to the UEFI crt0 object file (default: `/usr/lib/crt0-efi-x86_64.o`)
+- `EFI_LDS`: Path to the UEFI linker script (default: `/usr/lib/elf_x86_64_efi.lds`)
+- `BIOS_FD`: Path to the OVMF BIOS image for QEMU (default: `/usr/share/OVMF/FV/OVMF.fd`)
+- `DISK_BLOCK_COUNT`: Number of blocks in the disk image (default: 204800)
+- `DISK_BLOCK_SIZE_BYTES`: Size of each block in bytes (default: 512)
+
+Example usage:
+
+```sh
+make INCLUDE_DIRS="/path/to/efi/headers" LD_OBJ="/path/to/crt0.o"
+```
+
+## Writing to a Disk
+
+To write the bootloader image to a physical disk (use with caution!):
+
+```sh
+sudo dd if=reboot.img of=/dev/sdX bs=4M status=progress
+```
+
+Replace `/dev/sdX` with the appropriate disk device. Be absolutely certain you're writing to the correct disk, as this will overwrite all existing data.
+
+## How it Works
+
+The bootloader is a minimal UEFI application that calls the UEFI firmware's ResetSystem function to immediately reboot the system. The Makefile compiles this application and creates a GPT-formatted disk image containing an EFI System Partition with the bootloader installed.