[Buildroot] [PATCHv2 1/2] board/qemu/post-image.sh: start from a shell

[Romain Naour]

Usually the qemu command line start directly with "qemu-system-<arch> ...".
But the command line for qemu_arm_vexpress_tz_defconfig start by doing
"cd output/images && ../host/bin/qemu-system-arm". This is necessary
since boot binaries, except BL1, are primarily loaded via semi-hosting
so all binaries has to reside in the same directory as QEMU is started
from [1].

The start-qemu.sh script fail to start qemu since it use exec on the
"cd" command. To work around this issue, use "exec sh -c":
exec sh -c "${QEMU_CMD_LINE} \${EXTRA_ARGS}"

[1] https://github.com/ARM-software/arm-trusted-firmware/blob/4ebbea9592ab37fc62217d0ac62fa13a3e063527/docs/plat/qemu.rst

Signed-off-by: Romain Naour <romain.naour at gmail.com>
Cc: Yann E. MORIN <yann.morin.1998 at free.fr>
---
v2: escape double quote for -append
---
 board/qemu/post-image.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/board/qemu/post-image.sh b/board/qemu/post-image.sh
index 9a4d216274..07ce9c0d09 100755
--- a/board/qemu/post-image.sh
+++ b/board/qemu/post-image.sh
@@ -27,6 +27,9 @@ QEMU_CMD_LINE="${QEMU_CMD_LINE//output\/images/\${IMAGE_DIR\}}"
 DEFAULT_ARGS="$(sed -r -e '/-serial stdio/!d; s/.*(-serial stdio).*/\1/' <<<"${QEMU_CMD_LINE}")"
 QEMU_CMD_LINE="${QEMU_CMD_LINE//-serial stdio/}"
 
+# Escape -append double quotes
+QEMU_CMD_LINE=$(echo ${QEMU_CMD_LINE} | sed "s%\"%\\\\\"%g")
+
 # Disable graphical output and redirect serial I/Os to console
 case ${DEFCONFIG_NAME} in
   (qemu_sh4eb_r2d_defconfig|qemu_sh4_r2d_defconfig)
@@ -49,7 +52,7 @@ cat <<-_EOF_ > "${START_QEMU_SCRIPT}"
 	fi
 
 	export PATH="${HOST_DIR}/bin:\${PATH}"
-	exec ${QEMU_CMD_LINE} \${EXTRA_ARGS}
+	exec sh -c "${QEMU_CMD_LINE} \${EXTRA_ARGS}"
 _EOF_
 
 chmod +x "${START_QEMU_SCRIPT}"
-- 
2.25.4