initrd: Route runtime CBFS reads via flashprog

Signed-off-by: Sean Rhodes <sean@starlabs.systems>

Author: Sean-StarLabs

doc/starlabs.md

@@ -0,0 +1,27 @@
+# Star Labs builds
+
+Star Labs Cezanne boards require the maintained AMD binary tree in addition to
+the files carried by the Heads tree. The binary tree is not committed here.
+
+Mount the maintained tree read-only at the build path before configuring or
+building either Cezanne target:
+
+```sh
+mkdir -p build/x86/amd_binaries
+mount --bind /path/to/starlabs/amd_binaries build/x86/amd_binaries
+mount -o remount,bind,ro build/x86/amd_binaries
+```
+
+The mounted tree must contain the paths listed in
+`config/starlabs-amd-binaries.sha256`, including:
+
+```text
+CZN/APCB/
+CZN/PSP/
+FSP/CEZANNE_M.fd
+FSP/CEZANNE_S.fd
+```
+
+The build verifies the mounted files against
+`config/starlabs-amd-binaries.sha256` before coreboot configuration and build
+steps run. Update that manifest when the maintained binary input changes.

initrd/bin/cbfs.sh

@@ -5,8 +5,20 @@ set -e -o pipefail
 
 TRACE_FUNC
 
+cbfs_has_rom_arg() {
+	for arg in "$@"; do
+		if [ "$arg" = "-o" ]; then
+			return 0
+		fi
+	done
+	return 1
+}
+
 if pnor "$2" -r HBI > /tmp/pnor.part 2>/dev/null; then
-    cbfs "$@" -o /tmp/pnor.part && pnor "$2" -w HBI < /tmp/pnor.part
+	cbfs "$@" -o /tmp/pnor.part && pnor "$2" -w HBI < /tmp/pnor.part
+elif [ "$CONFIG_CBFS_VIA_FLASHPROG" = "y" ] && ! cbfs_has_rom_arg "$@"; then
+	/bin/flashprog -p internal --fmap -i COREBOOT -i FMAP -r /tmp/cbfs-current.rom >/dev/null
+	cbfs "$@" -o /tmp/cbfs-current.rom
 else
-    cbfs "$@"
+	cbfs "$@"
 fi

initrd/bin/inject_firmware.sh

@@ -40,9 +40,9 @@ mkdir "$INITRD_ROOT"
 unpack_initramfs.sh "$ORIG_INITRD" "$INITRD_ROOT" init
 
 # Copy the firmware into the initrd
-for f in $(cbfs -l | grep firmware); do
+for f in $(cbfs.sh -l | grep firmware); do
 	mkdir -p "$INITRD_ROOT/$(dirname "$f")"
-	cbfs -r "$f" > "$INITRD_ROOT/$f"
+	cbfs.sh -r "$f" > "$INITRD_ROOT/$f"
 	if [[ "$f" == *.lzma ]]; then
 		lzma -d "$INITRD_ROOT/$f"
 	fi

initrd/etc/functions.sh

@@ -489,7 +489,9 @@ preserve_rom() {
 	#   based on the --clean / -c flag passed by the user or calling script.
 	# Files preserved: all CBFS type-50 entries under the 'heads/' prefix.
 	new_rom="$1"
-	old_files=$(cbfs -t 50 -l 2>/dev/null | grep "^heads/")
+	all_old_files=$(cbfs.sh -t 50 -l 2>/dev/null) ||
+		DIE "preserve_rom: failed to list current CBFS"
+	old_files=$(echo "$all_old_files" | grep "^heads/" || true)
 	old_file_count=$(echo "$old_files" | wc -w)
 
 	if [ "$old_file_count" -eq 0 ]; then
@@ -502,13 +504,13 @@ preserve_rom() {
 	DEBUG "preserve_rom: scanning $new_rom for existing heads/* entries to skip"
 
 	for old_file in $(echo $old_files); do
-		new_file=$(cbfs.sh -o $1 -l | grep -Fx "$old_file")
+		new_file=$(cbfs.sh -o "$new_rom" -l | grep -Fx "$old_file" || true)
 		if [ -z "$new_file" ]; then
 			DEBUG "preserve_rom: $old_file not found in new ROM — copying from current CBFS"
-			cbfs -t 50 -r $old_file >/tmp/rom.$$ ||
+			cbfs.sh -t 50 -r "$old_file" >/tmp/rom.$$ ||
 				DIE "preserve_rom: failed to read $old_file from current CBFS"
-			cbfs.sh -o $1 -a $old_file -f /tmp/rom.$$ ||
-				DIE "preserve_rom: failed to write $old_file to $1"
+			cbfs.sh -o "$new_rom" -a "$old_file" -f /tmp/rom.$$ ||
+				DIE "preserve_rom: failed to write $old_file to $new_rom"
 		else
 			DEBUG "preserve_rom: $old_file already present in new ROM — skipped"
 		fi
@@ -3638,4 +3640,3 @@ _build_final_cmdline() {
 	DEBUG "_build_final_cmdline: final='$_combined'"
 	echo "$_combined"
 }
-