diff options
| -rw-r--r-- | projects/grub/configs/bios/modules-minimal | 1 | ||||
| -rw-r--r-- | projects/grub/configs/bios/size | 2 | ||||
| -rwxr-xr-x | projects/grub/grub-helper | 168 |
3 files changed, 141 insertions, 30 deletions
diff --git a/projects/grub/configs/bios/modules-minimal b/projects/grub/configs/bios/modules-minimal index 604b8091..b9684529 100644 --- a/projects/grub/configs/bios/modules-minimal +++ b/projects/grub/configs/bios/modules-minimal @@ -5,6 +5,7 @@ cbmemc configfile ehci ext2 +fat halt loadenv memdisk diff --git a/projects/grub/configs/bios/size b/projects/grub/configs/bios/size index a7625603..693832e1 100644 --- a/projects/grub/configs/bios/size +++ b/projects/grub/configs/bios/size @@ -1 +1 @@ -160 +2880 diff --git a/projects/grub/grub-helper b/projects/grub/grub-helper index 596f7d96..ccc9cd73 100755 --- a/projects/grub/grub-helper +++ b/projects/grub/grub-helper @@ -1,6 +1,6 @@ #!/usr/bin/env bash -# Copyright (C) 2017 Andrew Robbins <contact@andrewrobbins.info> +# Copyright (C) 2017,2018 Andrew Robbins <contact@andrewrobbins.info> # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -62,6 +62,47 @@ grub_modmin_path() { project_file_path "$project" "$CONFIGS" "$MODMIN" "$@" } +grub_bo_search() { + local pattern="$1" + local comparand="$2" + + grep -Fbof <(grub_bo_dump "$pattern") <(grub_bo_dump "$comparand") | cut -d: -f1 +} + +grub_bo_dump() { + local file="$1" + + od -Anx -t x1 -w16 -v "$file" | paste -sd '' | tr -d ' ' +} + +grub_bo() { + local pattern="$1" + local comparand="$2" + + local nibble_offset="$(grub_bo_search "$pattern" "$comparand")" + + if [[ -n "$nibble_offset" ]]; then + printf '0x%X\n' $((nibble_offset / 2)) + else + return 1 + fi +} + +grub_blocklist_format() { + local blocklist="$1" + local byte + + while read -N 2 byte; do + printf '%s' "\\x$byte" + done <<< "$blocklist" +} + +grub_blocklist_generate() { + local -i byte_offset="$1" + + printf '%04x' $((byte_offset / 512)) | tac -rs .. +} + grub_copy_modules() { local grub_module_dir="$sources_path/grub-core" local keep_dir="$build_path/$(grub_format "$target" "$@")" @@ -135,25 +176,31 @@ grub_build_bootable_image() { local grub_mkimage="$sources_path/grub-mkimage" local grub_module_dir="$sources_path/grub-core" - local grubimg="$build_path/grub.img" local grub_bootimg="$grub_module_dir/boot.img" - local grub_bootable_img="$build_path/grub2" + local grub_coreimg="$build_path/core.img" "$grub_mkimage" \ --config="$config_path" \ --directory="$grub_module_dir" \ - --output="$grubimg" \ + --output="$grub_coreimg" \ --format="$format" \ --prefix="$prefix" \ "${modmin[@]}" - cat "$grub_bootimg" "$grubimg" > "$grub_bootable_img" - rm -f "$grubimg" + cp -a "$grub_bootimg" "$build_path" } grub_build_floppy_image() { - local grubimg="$build_path/grub2" - local tempfile="$build_path/temp.file" + local floppyimg="$build_path/floppy.img" + local format="$(grub_format "$target" "$@")" + local grub_module_dir="$sources_path/grub-core" + local size="$(grub_size "$target" "$@")" + + local -a modules + + for module in "$grub_module_dir"/*.mod; do + modules+=($module) + done if ! grub_build_bootable_image "$@"; then printf '\n%s\n\n' "Error: Failed to build a GRUB image" 1>&2 @@ -161,33 +208,19 @@ grub_build_floppy_image() { return 1 fi - local size="$(grub_size "$target" "$@")" - - # Pre-allocate a floppy-sized image + # Pre-allocate a floppy-sized image with a FAT12 filesystem # SeaBIOS requires floppy images to have a "correct" size - if ! [[ -e "$tempfile" ]]; then - dd if=/dev/zero of="$tempfile" bs=1024 count="${size:-160}" + if ! [[ -e "$floppyimg" ]]; then + mkfs.fat -C -D 0x00 -F 12 -M 0xF9 -n SEAGRUB --invariant "$floppyimg" "$size" else - printf '\n%s\n\n' "Error: File $tempfile already exists!" 1>&2 + printf '\n%s\n\n' "Error: File $floppyimg already exists!" 1>&2 return 1 fi - local -i grubimg_size="$(stat -c %s "$grubimg")" - local -i floppy_size="$((${size:-160} * 1024))" - - # Graft the GRUB image onto the blank floppy image - if ((grubimg_size <= floppy_size)); then - dd if="$grubimg" of="$tempfile" bs=1 conv=notrunc - - rm -f "$grubimg" - mv "$tempfile" "$grubimg" - else - printf '\n%s' "Error: Image ${grubimg##*/} is too large; " 1>&2 - printf '%s\n\n' "it must be less than ${floppy_size}KiB in size" 1>&2 - - return 1 - fi + grub_floppy_image_mmd "$floppyimg" /boot /boot/grub "/boot/grub/$format" + grub_floppy_image_mcopy "$floppyimg" "/boot/grub/$format" "${modules[@]}" + grub_floppy_image_make_bootable "$floppyimg" } grub_build_standalone_image() { @@ -216,3 +249,80 @@ grub_build_standalone_image() { --output="$grubimg" \ /boot/grub/grub.cfg="$config_path" } + +grub_floppy_image_mmd() { + local img="$1" + local -a dirs=("${@:2}") + + if [[ -n "$img" ]]; then + mmd -i "$img" "${dirs[@]}" + else + return 1 + fi +} + +grub_floppy_image_mcopy() { + local img="$1" + local target="$2" + local -a files=("${@:3}") + + if [[ -z "$img" ]]; then + return 1 + elif [[ -z "${files[@]}" ]]; then + mcopy -i "$img" -pv "::$target" + else + mcopy -i "$img" -pQv "${files[@]}" "::$target" + fi +} + +grub_floppy_image_make_bootable() { + local floppyimg="$1" + local bootimg="$build_path/boot.img" + local coreimg="$build_path/core.img" + local oem_name='\x4C\x49\x42\x52\x45\x20\x20\x20' + + # write $floppyimg Bios Parameter Block to $bootimg first + dd if="$floppyimg" of="$bootimg" bs=1 skip=11 seek=11 count=52 conv=notrunc + dd if=<(printf "$oem_name") of="$bootimg" bs=1 seek=3 conv=notrunc + dd if=/dev/zero of="$floppyimg" count=1 conv=notrunc + dd if="$bootimg" of="$floppyimg" conv=notrunc + + grub_floppy_image_mcopy "$floppyimg" /boot/grub "$bootimg" + grub_floppy_image_mcopy "$floppyimg" /boot/grub "$coreimg" + + grub_floppy_image_update_blocklists "$coreimg" "$floppyimg" + rm -f "$bootimg" "$coreimg" +} + +grub_floppy_image_update_blocklists() { + local coreimg="$1" + local floppyimg="$2" + + local -i coreimg_offset="$(grub_bo "$coreimg" "$floppyimg")" + local -i coreimg_second_sector_offset=$((coreimg_offset + 0x200)) + + local -i boot_record_blocklist_offset=0x5C + local -i coreimg_blocklist_offset=$((coreimg_offset + 0x1F4)) + + # blocklists (little endian) describe the $coreimg_offset in sectors + local boot_record_blocklist="$(grub_blocklist_generate "$coreimg_offset")" + local coreimg_blocklist="$(grub_blocklist_generate "$coreimg_second_sector_offset")" + + if [[ $coreimg_offset -gt 0 ]]; then + dd if=<(printf "$(grub_blocklist_format "$boot_record_blocklist")") \ + of="$floppyimg" \ + bs=1 \ + seek="$boot_record_blocklist_offset" \ + conv=notrunc + + dd if=<(printf "$(grub_blocklist_format "$coreimg_blocklist")") \ + of="$floppyimg" \ + bs=1 \ + seek="$coreimg_blocklist_offset" \ + conv=notrunc + else + printf 1>&2 '%s\n' "Error: ${coreimg##*/} offset not found" + + return 1 + fi +} |