Add hardware reboot cause as actual reboot cause for soft reboot failed

Author: sujinmkang

scripts/determine-reboot-cause

@@ -181,18 +181,41 @@ def main():
     # any additional_reboot_info it will be stored as a "comment" in REBOOT_CAUSE_HISTORY_FILE
     additional_reboot_info = "N/A"
 
-    # Check if the previous reboot was warm/fast reboot by testing whether there is "fast|fastfast|warm" in /proc/cmdline
+    # 1. Check if the previous reboot was warm/fast reboot by testing whether there is "fast|fastfast|warm" in /proc/cmdline
     proc_cmdline_reboot_cause = find_proc_cmdline_reboot_cause()
 
-    # If /proc/cmdline does not indicate reboot cause, check if the previous reboot was caused by hardware
-    if proc_cmdline_reboot_cause is None:
-        previous_reboot_cause = find_hardware_reboot_cause()
-        if previous_reboot_cause.startswith(REBOOT_CAUSE_NON_HARDWARE):
-            # If the reboot cause is non-hardware, get the reboot cause from REBOOT_CAUSE_FILE
-            previous_reboot_cause = find_software_reboot_cause()
+    # 2. Check if the previous reboot was caused by hardware
+    #    If yes, the hardware reboot cause will be treated as the reboot cause
+    hardware_reboot_cause = find_hardware_reboot_cause()
+
+    # 3. If there is a REBOOT_CAUSE_FILE, it will contain any software-related
+    #    reboot info. We will use it as the previous cause.
+    software_reboot_cause = find_software_reboot_cause()
+
+    # The main decision logic of the reboot cause:
+    # If there is a reboot cause indicated by /proc/cmdline, it should be warmreboot/fastreboot
+    #   the software_reboot_cause which is the content of /hosts/reboot-cause/reboot-cause.txt
+    #   will be treated as the reboot cause
+    # Elif there is a reboot cause indicated by platform API,
+    #   the hardware_reboot_cause will be treated as the reboot cause
+    # Else the software_reboot_cause will be treated as the reboot cause
+    if proc_cmdline_reboot_cause is not None:
+        if not hardware_reboot_cause.startswith(REBOOT_CAUSE_NON_HARDWARE):
+            # Add the hardware_reboot_cause as actual reboot cause
+            previous_reboot_cause = hardware_reboot_cause
+            additional_reboot_info = software_reboot_cause
+        else:
+            previous_reboot_cause = software_reboot_cause
+    elif hardware_reboot_cause is not None:
+        # Check if any software reboot was issued before this hardware reboot happened
+        if software_reboot_cause is not REBOOT_CAUSE_UNKNOWN:
+            previous_reboot_cause = hardware_reboot_cause
+            additional_reboot_info = software_reboot_cause
+        else:
+            previous_reboot_cause = hardware_reboot_cause
     else:
         # Get the reboot cause from REBOOT_CAUSE_FILE
-        previous_reboot_cause = find_software_reboot_cause()
+        previous_reboot_cause = software_reboot_cause
 
     # Current time
     reboot_cause_gen_time = str(datetime.datetime.now().strftime('%Y_%m_%d_%H_%M_%S'))