[PATCH] tools: k3_gen_x509_cert: Allow selecting early JTAG debug value

Andrew F. Davis afd at ti.com
Wed Apr 22 19:09:41 CEST 2020


When authenticating the initial boot binary the ROM will check a debug
type value in the certificate and based on that open JTAG access to that
core.

The default is currently full access, on HS this is useful for early
developers, but should not be the default as to prevent end system
integrators from unintentionally leaving this open.

On non-HS devices JTAG is left open anyway so this does not change
behavior on those devices. Change the default to off and allow it to be
switched back on by command line flag if needed.

Signed-off-by: Andrew F. Davis <afd at ti.com>
---
 tools/k3_gen_x509_cert.sh | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/k3_gen_x509_cert.sh b/tools/k3_gen_x509_cert.sh
index b6d055f6f5..298cec1313 100755
--- a/tools/k3_gen_x509_cert.sh
+++ b/tools/k3_gen_x509_cert.sh
@@ -12,6 +12,7 @@ RAND_KEY=eckey.pem
 LOADADDR=0x41c00000
 BOOTCORE_OPTS=0
 BOOTCORE=16
+DEBUG_TYPE=0
 
 gen_degen_template() {
 cat << 'EOF' > degen-template.txt
@@ -79,7 +80,7 @@ cat << 'EOF' > x509-template.txt
 
  [ debug ]
  debugUID = FORMAT:HEX,OCT:0000000000000000000000000000000000000000000000000000000000000000
- debugType = INTEGER:4
+ debugType = INTEGER:TEST_DEBUG_TYPE
  coreDbgEn = INTEGER:0
  coreDbgSecEn = INTEGER:0
 EOF
@@ -151,8 +152,9 @@ options_help[k]="key_file:file with key inside it. If not provided script genera
 options_help[o]="output_file:Name of the final output file. default to $OUTPUT"
 options_help[c]="core_id:target core id on which the image would be running. Default to $BOOTCORE"
 options_help[l]="loadaddr: Target load address of the binary in hex. Default to $LOADADDR"
+options_help[d]="debug_type: Debug type, set to 4 to enable early JTAG. Default to $DEBUG_TYPE"
 
-while getopts "b:k:o:c:l:h" opt
+while getopts "b:k:o:c:l:d:h" opt
 do
 	case $opt in
 	b)
@@ -170,6 +172,9 @@ do
 	c)
 		BOOTCORE=$OPTARG
 	;;
+	d)
+		DEBUG_TYPE=$OPTARG
+	;;
 	h)
 		usage
 		exit 0
@@ -224,12 +229,15 @@ gen_cert() {
 	#echo "	LOADADDR = 0x$ADDR"
 	#echo "	IMAGE_SIZE = $BIN_SIZE"
 	#echo "	CERT_TYPE = $CERTTYPE"
+	#echo "	DEBUG_TYPE = $DEBUG_TYPE"
 	sed -e "s/TEST_IMAGE_LENGTH/$BIN_SIZE/"	\
 		-e "s/TEST_IMAGE_SHA_VAL/$SHA_VAL/" \
 		-e "s/TEST_CERT_TYPE/$CERTTYPE/" \
 		-e "s/TEST_BOOT_CORE_OPTS/$BOOTCORE_OPTS/" \
 		-e "s/TEST_BOOT_CORE/$BOOTCORE/" \
-		-e "s/TEST_BOOT_ADDR/$ADDR/" x509-template.txt > $TEMP_X509
+		-e "s/TEST_BOOT_ADDR/$ADDR/" \
+		-e "s/TEST_DEBUG_TYPE/$DEBUG_TYPE/" \
+		x509-template.txt > $TEMP_X509
 	openssl req -new -x509 -key $KEY -nodes -outform DER -out $CERT -config $TEMP_X509 -sha512
 }
 
-- 
2.17.1



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