From 1536da3497050878d358234ff2a52f6d89ca80b1 Mon Sep 17 00:00:00 2001
From: Rahix <rahix@rahix.de>
Date: Fri, 4 Oct 2019 09:58:29 +0200
Subject: [PATCH] feat(epicardium): Add a panic() function
In unrecoverable situations we should provide a common way to output the
cause of the error and then reset the CPU. The panic() function is
mean to be exactly that. It outputs the error-cause, stack-trace, and
firmware revision, accompanied by a link to the issue-tracker to
encourage people to report the error. After a timeout of ~1.5s it
resets the CPU and reboots.
Future Work:
- Right now, the stack-trace only has a depth of one which is the
return address from where panic() was called. In the future it might
make sense to provide a deeper stack-trace if a robust implementation
is possible.
- Integration of @msgctl's faultscreen (!79) so users who don't have
the serial console open at all times can also see what happened.
Signed-off-by: Rahix <rahix@rahix.de>
---
epicardium/modules/meson.build | 1 +
epicardium/modules/modules.h | 4 +++
epicardium/modules/panic.c | 63 ++++++++++++++++++++++++++++++++++
3 files changed, 68 insertions(+)
create mode 100644 epicardium/modules/panic.c
diff --git a/epicardium/modules/meson.build b/epicardium/modules/meson.build
index 21a04ba5..022397ca 100644
--- a/epicardium/modules/meson.build
+++ b/epicardium/modules/meson.build
@@ -14,6 +14,7 @@ module_sources = files(
'light_sensor.c',
'log.c',
'max30001.c',
+ 'panic.c',
'personal_state.c',
'pmic.c',
'rtc.c',
diff --git a/epicardium/modules/modules.h b/epicardium/modules/modules.h
index 465c78a4..bf59566b 100644
--- a/epicardium/modules/modules.h
+++ b/epicardium/modules/modules.h
@@ -8,6 +8,10 @@
#include <stdint.h>
#include <stdbool.h>
+/* ---------- Panic -------------------------------------------------------- */
+void panic(const char *format, ...)
+ __attribute__((noreturn, format(printf, 1, 2)));
+
/* ---------- Dispatcher --------------------------------------------------- */
void vApiDispatcher(void *pvParameters);
void dispatcher_mutex_init(void);
diff --git a/epicardium/modules/panic.c b/epicardium/modules/panic.c
new file mode 100644
index 00000000..e37f3d7a
--- /dev/null
+++ b/epicardium/modules/panic.c
@@ -0,0 +1,63 @@
+/*
+ * Panic
+ * =====
+ *
+ * Under some conditions the firmware should crash and reboot automatically.
+ * This module provides the necessary facilities to do so.
+ *
+ * Note that a panic should indicate **only** logic-errors in the firmware or
+ * unrecoverable hardware conditions.
+ */
+
+#include "modules/log.h"
+#include "modules/modules.h"
+
+#include "card10.h"
+#include "card10-version.h"
+
+#include <stdio.h>
+#include <stdarg.h>
+
+void __attribute__((noreturn)) panic(const char *format, ...)
+{
+ /* Turn off interrupts. We won't get back from here anyway. */
+ __asm volatile("cpsid i" ::: "memory");
+
+ /*
+ * Turn off asynchronous printing because that won't ever work from
+ * here ...
+ */
+ serial_return_to_synchronous();
+
+ printf("\x1b[31;1m --- SYSTEM PANIC ---\n"
+ "\x1b[0;31m --- ---\n"
+ " --- ---\n"
+ "\x1b[0m A fatal error occured:\n \x1b[1m");
+
+ va_list ap;
+ va_start(ap, format);
+ vprintf(format, ap);
+ va_end(ap);
+
+ printf("\n"
+ "\x1b[0m\n"
+ " Firmware Version:\n"
+ "\x1b[35m %s\n",
+ CARD10_VERSION);
+
+ printf("\x1b[0m\n"
+ " Stack Trace:\n"
+ "\x1b[36m %p\n",
+ __builtin_return_address(0));
+
+ printf("\x1b[33m\n"
+ " Please report this error to the card10 firmware team!\n"
+ "\x1b[0m -> https://git.card10.badge.events.ccc.de/card10/firmware/issues/new?issue <-\n"
+ "\x1b[31m --- ====== ===== ---\x1b[0m\n");
+
+ for (int i = 0; i < 96000000; i++) {
+ __asm volatile("nop");
+ }
+
+ card10_reset();
+}
--
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