Uprev panic data struct version

The struct was changed in commit 74c34bbad, but the struct version was
left as 1. We need to uprev this so the data returned by host command is
useful.

BUG=chrome-os-partner:16901 chrome-os-partner:20548
TEST='ectool panicinfo' with new and old struct. Compare output with
output from console command 'panicinfo'.
BRANCH=None

Change-Id: I4df3142497dc5ee21d100c4cb8118fb7a0ce7a7e
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/60314
Reviewed-by: Daisuke Nojiri <dnojiri@google.com>

3 files changed, 34 insertions, 9 deletions

diff --git a/core/cortex-m/panic.c b/core/cortex-m/panic.c
index df3b08db57..85d0701b21 100644
--- a/core/cortex-m/panic.c
+++ b/core/cortex-m/panic.c
@@ -372,7 +372,7 @@ void report_panic(void)
 
 	pdata->magic = PANIC_DATA_MAGIC;
 	pdata->struct_size = sizeof(*pdata);
-	pdata->struct_version = 1;
+	pdata->struct_version = 2;
 	pdata->arch = PANIC_ARCH_CORTEX_M;
 	pdata->flags = 0;
 	pdata->reserved = 0;
diff --git a/include/panic.h b/include/panic.h
index 6caaf6a2d8..256ce84e87 100644
--- a/include/panic.h
+++ b/include/panic.h
@@ -14,11 +14,14 @@
 /* Data saved across reboots */
 struct panic_data {
 	uint8_t arch;             /* Architecture (PANIC_ARCH_*) */
-	uint8_t struct_version;   /* Structure version (currently 1) */
+	uint8_t struct_version;   /* Structure version (currently 2) */
 	uint8_t flags;            /* Flags (PANIC_DATA_FLAG_*) */
 	uint8_t reserved;         /* Reserved; set 0 */
 
-	uint32_t regs[12];        /* psp, ipsr, msp, r4-r11, lr(=exc_return) */
+	uint32_t regs[12];        /* psp, ipsr, msp, r4-r11, lr(=exc_return).
+				   * In version 1, that was uint32_t regs[11] =
+				   * psp, ipsr, lr, r4-r11
+				   */
 	uint32_t frame[8];        /* r0-r3, r12, lr, pc, xPSR */
 
 	uint32_t mmfs;
diff --git a/util/ectool.c b/util/ectool.c
index 702f8298b3..eafe2e5d93 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -1604,8 +1604,13 @@ int cmd_panic_info(int argc, char *argv[])
 	struct panic_data *pdata = (struct panic_data *)ec_inbuf;
 	const uint32_t *lregs = pdata->regs;
 	const uint32_t *sregs = NULL;
-	int in_handler;
+	enum {
+		ORIG_UNKNOWN = 0,
+		ORIG_PROCESS,
+		ORIG_HANDLER
+	} origin = ORIG_UNKNOWN;
 	int i;
+	const char *panic_origins[3] = {"", "PROCESS", "HANDLER"};
 
 	rv = ec_command(EC_CMD_GET_PANIC_INFO, 0, NULL, 0,
 			ec_inbuf, ec_max_insize);
@@ -1617,17 +1622,34 @@ int cmd_panic_info(int argc, char *argv[])
 		return 0;
 	}
 
+	/*
+	 * We only understand panic data with version <= 2. Warn the user
+	 * of higher versions.
+	 */
+	if (pdata->struct_version > 2)
+		fprintf(stderr,
+			"Unknown panic data version (%d). "
+			"Following data may be incorrect!\n",
+			pdata->struct_version);
+
 	printf("Saved panic data:%s\n",
 	       (pdata->flags & PANIC_DATA_FLAG_OLD_HOSTCMD ? "" : " (NEW)"));
 
-	in_handler = ((pdata->regs[11] & 0xf) == 1 ||
-		      (pdata->regs[11] & 0xf) == 9);
+	if (pdata->struct_version == 2)
+		origin = ((lregs[11] & 0xf) == 1 || (lregs[11] & 0xf) == 9) ?
+			 ORIG_HANDLER : ORIG_PROCESS;
 
+	/*
+	 * In pdata struct, 'regs', which is allocated before 'frame', has
+	 * one less elements in version 1. Therefore, if the data is from
+	 * version 1, shift 'sregs' by one element to align with 'frame' in
+	 * version 1.
+	 */
 	if (pdata->flags & PANIC_DATA_FLAG_FRAME_VALID)
-		sregs = pdata->frame;
+		sregs = pdata->frame - (pdata->struct_version == 1 ? 1 : 0);
 
 	printf("=== %s EXCEPTION: %02x ====== xPSR: %08x ===\n",
-	       in_handler ? "HANDLER" : "PROCESS",
+	       panic_origins[origin],
 	       lregs[1] & 0xff, sregs ? sregs[7] : -1);
 	for (i = 0; i < 4; ++i)
 		print_panic_reg(i, sregs, i);
@@ -1636,7 +1658,7 @@ int cmd_panic_info(int argc, char *argv[])
 	print_panic_reg(10, lregs, 9);
 	print_panic_reg(11, lregs, 10);
 	print_panic_reg(12, sregs, 4);
-	print_panic_reg(13, lregs, in_handler ? 2 : 0);
+	print_panic_reg(13, lregs, origin == ORIG_HANDLER ? 2 : 0);
 	print_panic_reg(14, sregs, 5);
 	print_panic_reg(15, sregs, 6);