Merge branch 'seagrub' of and_who/libreboot into master

1 files changed, 139 insertions, 29 deletions

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
+}