Save panic data across reboots, and add panicinfo command

Jump data now precedes the panic data, if any, in memory.

BUG=chrome-os-partner:7466
BRANCH=all
TEST=manual

1. boot system
2. sysjump rw --> display should stay on and keyboard should still work
   (this verifies jump data is properly read across sysjump still)
3. crash unaligned --> system should reboot
4. panicinfo --> should print the same crash dump as before, with (NEW)
5. panicinfo --> ditto, without (NEW)
6. sysjump rw
7. panicinfo --> ditto, without (NEW)

Change-Id: I88285724e82a15553ab25877e3d8ec4c74a4dd5a
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/32051

1 files changed, 48 insertions, 3 deletions

diff --git a/include/panic.h b/include/panic.h
index ecf6eb0232..bb3e853bd2 100644
--- a/include/panic.h
+++ b/include/panic.h
@@ -6,9 +6,47 @@
  * device, which is currently the UART.
  */
 
-#ifndef __PANIC_H
+#ifndef __CROS_EC_PANIC_H
+#define __CROS_EC_PANIC_H
+
 #include <stdarg.h>
 
+/* Data saved across reboots */
+struct panic_data {
+	uint8_t arch;             /* Architecture (PANIC_ARCH_*) */
+	uint8_t struct_version;   /* Structure version (currently 1) */
+	uint8_t flags;            /* Flags (PANIC_DATA_FLAG_*) */
+	uint8_t reserved;         /* Reserved; set 0 */
+
+	uint32_t regs[11];        /* psp, ipsr, lr, r4-r11 */
+	uint32_t frame[8];        /* r0-r3, r12, lr, pc, xPSR */
+
+	uint32_t mmfs;
+	uint32_t bfar;
+	uint32_t mfar;
+	uint32_t shcsr;
+	uint32_t hfsr;
+	uint32_t dfsr;
+
+	/*
+	 * These fields go at the END of the struct so we can find it at the
+	 * end of memory.
+	 */
+	uint32_t struct_size;     /* Size of this struct */
+	uint32_t magic;           /* PANIC_SAVE_MAGIC if valid */
+};
+
+#define PANIC_DATA_MAGIC 0x21636e50  /* "Pnc!" */
+#define PANIC_ARCH_CORTEX_M 1        /* Cortex-M architecture */
+
+/* Flags for panic_data.flags */
+/* panic_data.frame is valid */
+#define PANIC_DATA_FLAG_FRAME_VALID (1 << 0)
+/* Already printed at console */
+#define PANIC_DATA_FLAG_OLD_CONSOLE (1 << 1)
+/* Already returned via host command */
+#define PANIC_DATA_FLAG_OLD_HOSTCMD (1 << 2)
+
 /**
  * Write a character to the panic reporting device
  *
@@ -56,7 +94,6 @@ void panic_vprintf(const char *format, va_list args);
  */
 void panic_printf(const char *format, ...);
 
-
 /**
  * Report an assertion failure and reset
  *
@@ -82,4 +119,12 @@ void panic(const char *msg);
  */
 void ignore_bus_fault(int ignored);
 
-#endif
+/**
+ * Return a pointer to the saved data from a previous panic.
+ *
+ * @param pointer to the panic data, or NULL if none available (for example,
+ * the last reboot was not caused by a panic).
+ */
+struct panic_data *panic_get_data(void);
+
+#endif  /* __CROS_EC_PANIC_H */