Add sample crash console functions

Platforms that wish to use the sample functions have to add the file to
their Makefile. It is not included by default.

Change-Id: I713617bb58dc218967199248f68da86241d7ec40
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

2 files changed, 184 insertions, 0 deletions

diff --git a/plat/common/aarch32/crash_console_helpers.S b/plat/common/aarch32/crash_console_helpers.S
new file mode 100644
index 00000000..fc37c08f
--- /dev/null
+++ b/plat/common/aarch32/crash_console_helpers.S
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * If a platform wishes to use the functions in this file it has to be added to
+ * the Makefile of the platform. It is not included in the common Makefile.
+ */
+
+#include <asm_macros.S>
+#include <console.h>
+
+	.globl	plat_crash_console_init
+	.globl	plat_crash_console_putc
+	.globl	plat_crash_console_flush
+
+#if MULTI_CONSOLE_API
+
+	/* -----------------------------------------------------
+	 * int plat_crash_console_init(void)
+	 * Use normal console by default. Switch it to crash
+	 * mode so serial consoles become active again.
+	 * NOTE: This default implementation will only work for
+	 * crashes that occur after a normal console (marked
+	 * valid for the crash state) has been registered with
+	 * the console framework. To debug crashes that occur
+	 * earlier, the platform has to override these functions
+	 * with an implementation that initializes a console
+	 * driver with hardcoded parameters. See
+	 * docs/porting-guide.rst for more information.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_init
+#if defined(IMAGE_BL1)
+	/*
+	 * BL1 code can possibly crash so early that the data segment is not yet
+	 * accessible. Don't risk undefined behavior by trying to run the normal
+	 * console framework. Platforms that want to debug BL1 will need to
+	 * override this with custom functions that can run from registers only.
+	 */
+	mov	r0, #0
+	bx	lr
+#else	/* IMAGE_BL1 */
+	mov	r3, lr
+	mov	r0, #CONSOLE_FLAG_CRASH
+	bl	console_switch_state
+	mov	r0, #1
+	bx	r3
+#endif
+endfunc plat_crash_console_init
+
+	/* -----------------------------------------------------
+	 * void plat_crash_console_putc(int character)
+	 * Output through the normal console by default.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_putc
+	b	console_putc
+endfunc plat_crash_console_putc
+
+	/* -----------------------------------------------------
+	 * void plat_crash_console_flush(void)
+	 * Flush normal console by default.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_flush
+	b	console_flush
+endfunc plat_crash_console_flush
+
+#else	/* MULTI_CONSOLE_API */
+
+	/* -----------------------------------------------------
+	 * In the old API these are all no-op stubs that need to
+	 * be overridden by the platform to be useful.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_init
+	mov	r0, #0
+	bx	lr
+endfunc plat_crash_console_init
+
+func plat_crash_console_putc
+	bx	lr
+endfunc plat_crash_console_putc
+
+func plat_crash_console_flush
+	bx	lr
+endfunc plat_crash_console_flush
+
+#endif
diff --git a/plat/common/aarch64/crash_console_helpers.S b/plat/common/aarch64/crash_console_helpers.S
new file mode 100644
index 00000000..5af8db25
--- /dev/null
+++ b/plat/common/aarch64/crash_console_helpers.S
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * If a platform wishes to use the functions in this file it has to be added to
+ * the Makefile of the platform. It is not included in the common Makefile.
+ */
+
+#include <asm_macros.S>
+#include <console.h>
+
+	.globl	plat_crash_console_init
+	.globl	plat_crash_console_putc
+	.globl	plat_crash_console_flush
+
+#if MULTI_CONSOLE_API
+
+	/* -----------------------------------------------------
+	 * int plat_crash_console_init(void)
+	 * Use normal console by default. Switch it to crash
+	 * mode so serial consoles become active again.
+	 * NOTE: This default implementation will only work for
+	 * crashes that occur after a normal console (marked
+	 * valid for the crash state) has been registered with
+	 * the console framework. To debug crashes that occur
+	 * earlier, the platform has to override these functions
+	 * with an implementation that initializes a console
+	 * driver with hardcoded parameters. See
+	 * docs/porting-guide.rst for more information.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_init
+#if defined(IMAGE_BL1)
+	/*
+	 * BL1 code can possibly crash so early that the data segment is not yet
+	 * accessible. Don't risk undefined behavior by trying to run the normal
+	 * console framework. Platforms that want to debug BL1 will need to
+	 * override this with custom functions that can run from registers only.
+	 */
+	mov	x0, #0
+	ret
+#else	/* IMAGE_BL1 */
+	mov	x3, x30
+	mov	x0, #CONSOLE_FLAG_CRASH
+	bl	console_switch_state
+	mov	x0, #1
+	ret	x3
+#endif
+endfunc plat_crash_console_init
+
+	/* -----------------------------------------------------
+	 * void plat_crash_console_putc(int character)
+	 * Output through the normal console by default.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_putc
+	b	console_putc
+endfunc plat_crash_console_putc
+
+	/* -----------------------------------------------------
+	 * void plat_crash_console_flush(void)
+	 * Flush normal console by default.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_flush
+	b	console_flush
+endfunc plat_crash_console_flush
+
+#else	/* MULTI_CONSOLE_API */
+
+	/* -----------------------------------------------------
+	 * In the old API these are all no-op stubs that need to
+	 * be overridden by the platform to be useful.
+	 * -----------------------------------------------------
+	 */
+func plat_crash_console_init
+	mov	x0, #0
+	ret
+endfunc plat_crash_console_init
+
+func plat_crash_console_putc
+	ret
+endfunc plat_crash_console_putc
+
+func plat_crash_console_flush
+	ret
+endfunc plat_crash_console_flush
+
+#endif