Rework the crash reporting in BL3-1 to use less stack

This patch reworks the crash reporting mechanism to further
optimise the stack and code size. The reporting makes use
of assembly console functions to avoid calling C Runtime
to report the CPU state. The crash buffer requirement is
reduced to 64 bytes with this implementation. The crash
buffer is now part of per-cpu data which makes retrieving
the crash buffer trivial.

Also now panic() will use crash reporting if
invoked from BL3-1.

Fixes ARM-software/tf-issues#199

Change-Id: I79d27a4524583d723483165dc40801f45e627da5

2 files changed, 47 insertions, 96 deletions

diff --git a/common/aarch64/assert.S b/common/aarch64/debug.S
index a62c8f51..b7d7ac23 100644
--- a/common/aarch64/assert.S
+++ b/common/aarch64/debug.S
@@ -139,3 +139,50 @@ func asm_print_hex
 	cbnz	x5, 1b
 	ret	x3
 
+	/***********************************************************
+	 * The common implementation of do_panic for all BL stages
+	 ***********************************************************/
+
+.section .rodata.panic_str, "aS"
+	panic_msg: .asciz "PANIC at PC : 0x"
+
+/* ---------------------------------------------------------------------------
+ * do_panic assumes that it is invoked from a C Runtime Environment ie a
+ * valid stack exists. This call will not return.
+ * Clobber list : if CRASH_REPORTING is not enabled then x30, x0 - x6
+ * ---------------------------------------------------------------------------
+ */
+
+/* This is for the non el3 BL stages to compile through */
+	.weak el3_panic
+
+func do_panic
+#if CRASH_REPORTING
+	str	x0, [sp, #-0x10]!
+	mrs	x0, currentel
+	ubfx	x0, x0, #2, #2
+	cmp	x0, #0x3
+	ldr	x0, [sp], #0x10
+	b.eq	el3_panic
+#endif
+
+panic_common:
+/*
+ * el3_panic will be redefined by the BL31
+ * crash reporting mechanism (if enabled)
+ */
+el3_panic:
+	mov	x6, x30
+	bl	plat_crash_console_init
+	/* Check if the console is initialized */
+	cbz	x0, _panic_loop
+	/* The console is initialized */
+	adr	x4, panic_msg
+	bl	asm_print_str
+	mov	x4, x6
+	/* The panic location is lr -4 */
+	sub	x4, x4, #4
+	bl	asm_print_hex
+_panic_loop:
+	b	_panic_loop
+
diff --git a/common/debug.c b/common/debug.c
deleted file mode 100644
index be54f5de..00000000
--- a/common/debug.c
+++ /dev/null
@@ -1,96 +0,0 @@
-/*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-#include <console.h>
-#include <debug.h>
-#include <stdarg.h>
-#include <stdio.h>
-
-/******************************************************************
-* This function is invoked from assembler error handling routines and
-* prints out the string and the value in 64 bit hex format. These
-* are passed to the function as input parameters.
-********************************************************************/
-void print_string_value(char *s, unsigned long *mem)
-{
-	unsigned char i, temp;
-	unsigned long val;
-
-	while (*s) {
-		i = 16;
-		while (*s)
-			console_putc(*s++);
-
-		s++;
-
-		console_putc('\t');
-		console_putc(':');
-		console_putc('0');
-		console_putc('x');
-
-		val = *mem++;
-
-		while (i--) {
-			temp = (val >> (i << 2)) & 0xf;
-			if (temp <  0xa)
-				console_putc('0' + temp);
-			else
-				console_putc('A' + (temp - 0xa));
-		}
-		console_putc('\n');
-	}
-}
-
-/***********************************************************
- * The common implementation of do_panic for all BL stages
- ***********************************************************/
-
-#if DEBUG
-void __dead2 do_panic(const char *file, int line)
-{
-		tf_printf("PANIC in file: %s line: %d\n", file, line);
-		while (1)
-			;
-}
-#else
-void __dead2 do_panic(void)
-{
-	unsigned long pc_reg;
-	__asm__ volatile("mov %0, x30\n"
-					: "=r" (pc_reg) : );
-
-	/* x30 reports the next eligible instruction whereas we want the
-	 * place where panic() is invoked. Hence decrement by 4.
-	 */
-	tf_printf("PANIC in PC location 0x%016X\n", pc_reg - 0x4);
-	while (1)
-		;
-
-}
-#endif