lib.sh: get firmware path from log with journalctl

This patch simplifies the acquisition of firmware path
with journalctl, so that we can test if the firmware
loaded is using zephyr rtos by checking the occurrence
of 'zephyr' in the firmware binary.

Signed-off-by: Chao Song <chao.song@linux.intel.com>

case-lib/lib.sh

@@ -680,28 +680,23 @@ is_zephyr()
     test "$znum" -gt 10
 }
 
+get_firmware_path()
+{
+    journalctl_cmd -k |
+        awk '/sof.*request_firmware/ \
+            { sub(/^.*request_firmware/,""); last_loaded_file=$1 } \
+            END { print last_loaded_file }'
+}
+
 is_firmware_file_zephyr()
 {
-    local firmware_name firmware_path znum platform
-    # get the FW name and path
-    # TODO: optimize this part after driver can expose the FW path to userspace via debugfs
-    if is_ipc4; then
-        firmware_name=dsp_basefw.bin
-        fw_mod_para=/sys/module/snd_sof_pci/parameters/fw_path
-        if [ -s "$fw_mod_para" ]; then
-            firmware_path=$(cat $fw_mod_para)
-        else
-            # # FIXME: the kernel driver should give us the FW path
-            # https://github.com/thesofproject/linux/issues/3867
-            die "Failed to get the IPC4 FW path."
-        fi
-    else # for IPC3
-        platform=$(sof-dump-status.py -p)
-        firmware_name=sof-$platform.ri
-        firmware_path=$(sof-dump-status.py -P)
-    fi
+    local firmware_path znum
+
+    firmware_path=$(get_firmware_path)
+    [ -n "$firmware_path" ] ||
+        die 'firmware path not found from journalctl, no firmware loaded or debug option disabled?'
 
-    znum=$(strings "/lib/firmware/$firmware_path/$firmware_name" | grep -c -i zephyr)
+    znum=$(strings "/lib/firmware/$firmware_path" | grep -c -i zephyr)
     test "$znum" -gt 10
 }