Rework BL3-1 unhandled exception handling and reporting
This patch implements the register reporting when unhandled exceptions are
taken in BL3-1. Unhandled exceptions will result in a dump of registers
to the console, before halting execution by that CPU. The Crash Stack,
previously called the Exception Stack, is used for this activity.
This stack is used to preserve the CPU context and runtime stack
contents for debugging and analysis.
This also introduces the per_cpu_ptr_cache, referenced by tpidr_el3,
to provide easy access to some of BL3-1 per-cpu data structures.
Initially, this is used to provide a pointer to the Crash stack.
panic() now prints the the error file and line number in Debug mode
and prints the PC value in release mode.
The Exception Stack is renamed to Crash Stack with this patch.
The original intention of exception stack is no longer valid
since we intend to support several valid exceptions like IRQ
and FIQ in the trusted firmware context. This stack is now
utilized for dumping and reporting the system state when a
crash happens and hence the rename.
Fixes ARM-software/tf-issues#79 Improve reporting of unhandled exception
Change-Id: I260791dc05536b78547412d147193cdccae7811a
diff --git a/include/bl31/cm_macros.S b/include/bl31/cm_macros.S
index e82f3a3..f12f8c3 100644
--- a/include/bl31/cm_macros.S
+++ b/include/bl31/cm_macros.S
@@ -30,12 +30,6 @@
#include <arch.h>
#include <context.h>
- .macro switch_to_exception_stack reg1 reg2
- mov \reg1 , sp
- ldr \reg2, [\reg1, #CTX_EL3STATE_OFFSET + CTX_EXCEPTION_SP]
- mov sp, \reg2
- .endm
-
/* -----------------------------------------------------
* Handle SMC exceptions seperately from other sync.
* exceptions.
@@ -54,45 +48,10 @@
/* -----------------------------------------------------
* The following code handles any synchronous exception
- * that is not an SMC. SP_EL3 is pointing to a context
- * structure where all the scratch registers are saved.
- * An exception stack is also retrieved from the context
- * Currently, a register dump is printed since BL31 does
- * not expect any such exceptions.
+ * that is not an SMC.
* -----------------------------------------------------
*/
- bl save_gp_registers
- switch_to_exception_stack x0 x1
-
- /* Save the core_context pointer for handled faults */
- stp x0, xzr, [sp, #-0x10]!
- bl fault_handler
- ldp x0, xzr, [sp], #0x10
-
- mov sp, x0
- bl restore_gp_registers
- ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
- eret
- .endm
-
- /* -----------------------------------------------------
- * Use a platform defined mechanism to report an async.
- * exception.
- * -----------------------------------------------------
- */
- .macro handle_async_exception type
- str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
- bl save_gp_registers
- switch_to_exception_stack x0 x1
-
- /* Save the core_context pointer */
- stp x0, xzr, [sp, #-0x10]!
- mov x0, \type
- bl plat_report_exception
- ldp x0, xzr, [sp], #0x10
- mov sp, x0
- bl restore_gp_registers
- ldr x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ bl dump_state_and_die
.endm