From 78d26166a8ad1bc8d29822d45a6a382b87fa095d Mon Sep 17 00:00:00 2001
From: Awais Belal <awais_belal@mentor.com>
Date: Mon, 14 Jan 2019 19:40:50 +0500
Subject: [PATCH 4/7] init-install-efi: pick kernel and rootfs from grub.env

This allows for simply modifying variables to switch between
different kernels and rootfs from user-space without having to
modify grub configurations directly.

Signed-off-by: Awais Belal <awais_belal@mentor.com>
---
 init-install-efi.sh | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/init-install-efi.sh b/init-install-efi.sh
index 2adfe02..d69520f 100644
--- a/init-install-efi.sh
+++ b/init-install-efi.sh
@@ -287,6 +287,7 @@ mkdir -p $EFIDIR
 cp /run/media/$1/EFI/BOOT/*.efi $EFIDIR
 
 GRUBCFG="$EFIDIR/grub.cfg"
+GRUBENV="$EFIDIR/grub.env"
 if [ -f /run/media/$1/EFI/BOOT/grub.cfg ]; then
     root_part_uuid=$(blkid -o value -s PARTUUID ${rootfs1})
     cp /run/media/$1/EFI/BOOT/grub.cfg $GRUBCFG
@@ -297,9 +298,14 @@ if [ -f /run/media/$1/EFI/BOOT/grub.cfg ]; then
     sed -i "/initrd /d" $GRUBCFG
     # Delete any LABEL= strings
     sed -i "s/ LABEL=[^ ]*/ /" $GRUBCFG
+    # Mentor- SWUpdate - force grub to load our env which we'll use to specify RFS and KERNEL
+    sed -i "1iload_env --file ${GRUBENV#\/boot}" $GRUBCFG
+    # Set current and fallback rootfs using variable via our grub.env
+    grub-editenv $GRUBENV set "RFS=PARTUUID=$root_part_uuid"
+    grub-editenv $GRUBENV set "FB_RFS=PARTUUID=$root_part_uuid"
     # Replace root= and add additional standard boot options
     # We use root as a sentinel value, as vmlinuz is no longer guaranteed
-    sed -i "s/ root=[^ ]*/ root=PARTUUID=$root_part_uuid rw $rootwait quiet /g" $GRUBCFG
+    sed -i "s/ root=[^ ]*/ root=\$RFS rw $rootwait quiet /g" $GRUBCFG
 fi
 
 if [ -d /run/media/$1/loader ]; then
@@ -321,15 +327,25 @@ fi
 
 umount /tgt_root
 
+if [ -e "/proc/cmdline" ]; then
+    current_kernel=$(basename $(cat /proc/cmdline | awk '{print $1}' | cut -d"=" -f2))
+fi
 # Copy kernel artifacts. To add more artifacts just add to types
 # For now just support kernel types already being used by something in OE-core
 for types in bzImage zImage vmlinux vmlinuz fitImage; do
     # MEL - SWUpdate - copy all kernel images as <image>A, this is our first copy
     for kernel in `find /run/media/$1/ -name $types*`; do
         kernel_name=$(basename $kernel)
-        cp $kernel /boot/${kernel_name}A
+        cp ${kernel} /boot/${kernel_name}A
         if [ -e $GRUBCFG ]; then
-            sed -i "s/\/${kernel_name} /\/${kernel_name}A /" $GRUBCFG
+            if [ "${kernel_name}" = "${current_kernel}" ]; then
+                sed -i "s/\/${kernel_name} /\/\$KERNEL /" $GRUBCFG
+                # Set the current and fallback kernel to current kernel's <image>A
+                grub-editenv $GRUBENV set "KERNEL=${kernel_name}A"
+                grub-editenv $GRUBENV set "FB_KERNEL=${kernel_name}A"
+            else
+                sed -i "s/\/${kernel_name} /\/${kernel_name}A /" $GRUBCFG
+            fi
         fi
     done
 done
-- 
2.11.1