[PATCH] scripts/k3img: Add workaround for erratum i2474

[Sascha Hauer <s.hauer@pengutronix.de>]

The AM62Lx 1.0 is affected by erratum i2474:

| Boot: Certain second stage binaries fail for block based boot modes
|
| ROM fails to boot on SD, eMMC, USB-DFU, Serial NAND, GPMC NAND, and UART
| if certificate size is aligned to 128 Bytes.
| Certificate size must not be aligned to 128 bytes, however, individual
| components must be aligned to 128 bytes.

This adds a partial workaround for this issue. We align the components
to 128 bytes, but we do not make sure the certificate is not aligned to
128 bytes. We currently do not seem to hit this issue in barebox.
However, we add a alignment check just to make sure.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 scripts/k3img | 37 ++++++++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/scripts/k3img b/scripts/k3img
index bd86a43789..b00aa54e50 100755
--- a/scripts/k3img
+++ b/scripts/k3img
@@ -68,6 +68,11 @@ TMPDIR="$(mktemp -d)"
 components=${TMPDIR}/components
 ext_boot_info=${TMPDIR}/ext_boot_info
 data=${TMPDIR}/data
+component=${TMPDIR}/component
+
+align128() {
+	echo $(( ($1 + 0x7f) & ~0x7f ))
+}
 
 for i in $*; do
 	filename=$(echo "$i" | cut -d ":" -f 1)
@@ -76,8 +81,13 @@ for i in $*; do
 	compOpts=$(echo "$i" | cut -d ":" -f 4)
 	destAddr=$(echo "$i" | cut -d ":" -f 5)
 
-	sha=$(sha512sum $filename | sed 's/ .*//')
-	size=$(stat -L -c%s $filename)
+	cp $filename $component
+
+	size=$(stat -L -c%s $component)
+	size=$(align128 $size)
+	truncate --size=$size $component
+
+	sha=$(sha512sum $component | sed 's/ .*//')
 
 	total=$((total + size))
 	num_comp=$((num_comp + 1))
@@ -95,7 +105,8 @@ shaValue = FORMAT:HEX,OCT:$sha
 EndOfHereDocument
 
 	echo "comp$num_comp = SEQUENCE:comp$num_comp" >> $ext_boot_info
-	cat $filename >> $data
+
+	cat $component >> $data
 done
 
 echo >> $ext_boot_info
@@ -149,4 +160,24 @@ esac
 
 openssl req ${PKCS11OPTS} -new -x509 -key "${key}" -nodes -outform DER -out "${cert}" -config "${certcfg}" -sha512
 
+certsize=$(stat -L -c%s ${cert})
+
+#
+# AM62l erratum i2474:
+#
+#   Boot: Certain second stage binaries fail for block based boot modes
+#   ROM fails to boot on SD, eMMC, USB-DFU, Serial NAND, GPMC NAND, and
+#   UART if certificate size is aligned to 128 Bytes.
+#
+#   Certificate size must not be aligned to 128 bytes, however, individual
+#   components must be aligned to 128 bytes.
+#
+# The 128 byte alignment of the components is assured by this script. If you
+# hit the check below you have to add/remove a few bytes to/from $certcfg above.
+#
+if [ $certsize = $(align128 $certsize) ]; then
+	echo "$0: Certificate is 128 byte aligned, this is not allowed"
+	exit 1
+fi
+
 cat $cert $data > $out
-- 
2.47.3