From 3a917bb90b250217e65dabe0d7a5755f09026e20 Mon Sep 17 00:00:00 2001
From: Jonathon Hall <jonathon.hall@puri.sm>
Date: Thu, 3 Nov 2022 14:13:16 -0400
Subject: [PATCH] config-gui.sh: Extract utilities from config-gui.sh

Extract utilities from config-gui.sh for use in additional config
settings.  read_rom() reads the current ROM with a message for failure.
replace_rom_file() replaces a CBFS file in a ROM.  set_config() sets a
configuration variable in a file.

Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
---
 initrd/bin/config-gui.sh | 30 +++++++++++++-----------------
 initrd/etc/functions     | 26 ++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/initrd/bin/config-gui.sh b/initrd/bin/config-gui.sh
index 605fb4ec..014c8da7 100755
--- a/initrd/bin/config-gui.sh
+++ b/initrd/bin/config-gui.sh
@@ -11,6 +11,16 @@ ROOT_HASH_FILE="/boot/kexec_root_hashes.txt"
 
 param=$1
 
+# Read the current ROM; if it fails display an error and exit.
+read_rom() {
+  /bin/flash.sh -r "$1"
+  if [ ! -s "$1" ]; then
+    whiptail $BG_COLOR_ERROR --title 'ERROR: BIOS Read Failed!' \
+      --msgbox "Unable to read BIOS" 0 80
+    exit 1
+  fi
+}
+
 while true; do
   if [ ! -z "$param" ]; then
     # use first char from parameter
@@ -82,17 +92,9 @@ while true; do
         --msgbox "The /boot device was successfully changed to $SELECTED_FILE" 16 60
     ;;
     "s" )
-      /bin/flash.sh -r /tmp/config-gui.rom
-      if [ ! -s /tmp/config-gui.rom ]; then
-        whiptail $BG_COLOR_ERROR --title 'ERROR: BIOS Read Failed!' \
-          --msgbox "Unable to read BIOS" 16 60
-        exit 1
-      fi
+      read_rom /tmp/config-gui.rom
 
-      if (cbfs.sh -o /tmp/config-gui.rom -l | grep -q "heads/initrd/etc/config.user") then
-        cbfs.sh -o /tmp/config-gui.rom -d "heads/initrd/etc/config.user"
-      fi
-      cbfs.sh -o /tmp/config-gui.rom -a "heads/initrd/etc/config.user" -f /etc/config.user
+      replace_rom_file /tmp/config-gui.rom "heads/initrd/etc/config.user" /etc/config.user
 
       if (whiptail --title 'Update ROM?' \
           --yesno "This will reflash your BIOS with the updated version\n\nDo you want to proceed?" 0 80) then
@@ -111,13 +113,7 @@ while true; do
                   \nreset the /boot device, clear/reset the TPM (if present),
                   \nand reflash your BIOS with the cleaned configuration.
                   \n\nDo you want to proceed?" 0 80) then
-        # read current firmware
-        /bin/flash.sh -r /tmp/config-gui.rom
-        if [ ! -s /tmp/config-gui.rom ]; then
-          whiptail $BG_COLOR_ERROR --title 'ERROR: BIOS Read Failed!' \
-            --msgbox "Unable to read BIOS" 16 60
-          exit 1
-        fi
+        read_rom /tmp/config-gui.rom
         # clear local keyring
         rm /.gnupg/* | true
         # clear /boot signatures/checksums
diff --git a/initrd/etc/functions b/initrd/etc/functions
index 68a80ac5..fb8f90d9 100755
--- a/initrd/etc/functions
+++ b/initrd/etc/functions
@@ -267,6 +267,18 @@ check_config() {
 	|| die "Failed to copy kexec boot params to tmp"
 }
 
+# Replace a file in a ROM (add it if the file does not exist)
+replace_rom_file() {
+	ROM="$1"
+	ROM_FILE="$2"
+	NEW_FILE="$3"
+	
+	if (cbfs.sh -o "$ROM" -l | grep -q "$ROM_FILE") then
+		cbfs.sh -o "$ROM" -d "$ROM_FILE"
+	fi
+	cbfs.sh -o "$ROM" -a "$ROM_FILE" -f "$NEW_FILE"
+}
+
 replace_config() {
 	TRACE "Under /etc/functions:replace_config"
 	CONFIG_FILE=$1
@@ -284,6 +296,20 @@ replace_config() {
 	rm -f ${CONFIG_FILE}.tmp
 }
 
+# Set a config variable to a given value - replace it if it exists, or add it.
+# If added, the variable will be exported.
+set_config() {
+	CONFIG_FILE="$1"
+	CONFIG_OPTION="$2"
+	NEW_SETTING="$3"
+	
+	if grep -q "$CONFIG_OPTION" "$CONFIG_FILE"; then
+		replace_config "$CONFIG_FILE" "$CONFIG_OPTION" "$NEW_SETTING"
+	else
+		echo "export $CONFIG_OPTION=$NEW_SETTING" >>"$CONFIG_FILE"
+	fi
+}
+
 # Generate secret value using first 20 chars of ROM SHA256 hash
 secret_from_rom_hash() {
 	local ROM_IMAGE="/tmp/coreboot-notpm.rom"