scripts: add tool to adjust bl33 load address in existing FIP

Instead of rebuilding TF-A with a (newer) barebox, an existing image can
be repacked:

  fiptool update fip.bin --nt-fw images/barebox-dt-2nd.img \
    --hw-config build/arch/arm/dts/stm32mp157c-dk2.dtb

This may fail at runtime though, because the STM32MP default is to place
BL33 at the very start of RAM. The script introduced here offers
an alternative to rebuilding TF-A with adjust FW_CONFIG:

  ./scripts/fiptool_fwconfig -l 0xc0001000 mmcblk0p3

This will have barebox loaded 4096 bytes into the STM32MP SDRAM.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220220124736.3052502-7-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 39 insertions, 0 deletions

diff --git a/scripts/fiptool_fwconfig b/scripts/fiptool_fwconfig
new file mode 100755
index 0000000000..f76f450b04
--- /dev/null
+++ b/scripts/fiptool_fwconfig
@@ -0,0 +1,39 @@
+#!/bin/sh
+
+set -e
+
+# adjust bl33 load address in existing FIP
+
+FDTGET=${FDTGET:-fdtget}
+FDTPUT=${FDTPUT:-fdtput}
+
+if [ "$1" != "-l" ] || [ "$#" -ne 3 ]; then
+	echo "USAGE: $0 -l NT_LOAD_ADDR FIP" 1>&2
+	exit 1
+fi
+
+NEW_LOAD_ADDR=$(($2))
+FIP=$3
+FWCONFIG=".$FIP.fw-config.bin"
+
+fiptool unpack --fw-config "$FWCONFIG" --force "$FIP"
+
+MAX_SIZE="$($FDTGET -t u $FWCONFIG /dtb-registry/nt_fw max-size)"
+set $($FDTGET -t u $FWCONFIG /dtb-registry/nt_fw load-address)
+ENTRY=$1
+OLD_LOAD_ADDR=$2
+
+if [ $NEW_LOAD_ADDR -lt $OLD_LOAD_ADDR ] ||
+   [ $NEW_LOAD_ADDR -ge $((OLD_LOAD_ADDR + MAX_SIZE)) ]; then
+	printf "New load address 0x%08x out of bounds [0x%08x-0x%08x)\n" \
+		$NEW_LOAD_ADDR $OLD_LOAD_ADDR $((OLD_LOAD_ADDR + MAX_SIZE)) 1>&2
+	exit 1
+fi
+
+$FDTPUT -t u $FWCONFIG /dtb-registry/nt_fw load-address $ENTRY $NEW_LOAD_ADDR
+$FDTPUT -t u $FWCONFIG /dtb-registry/nt_fw max-size \
+	$((MAX_SIZE + OLD_LOAD_ADDR - NEW_LOAD_ADDR))
+
+fiptool update $FIP --fw-config $FWCONFIG
+
+rm $FWCONFIG