tegra124: Add a custom bootblock implementation.

This implementation is the same as the general one except that it removes all
the things that don't work on an ARMv4.

Change-Id: I1108a79cc656b26f7d48df20aef3016cf5ae3182
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171019
Reviewed-by: Ronald Minnich <rminnich@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit d1436288d3b025af27a8d28ba94b589940ead504)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6713
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/soc/nvidia/tegra124/Kconfig

@@ -2,9 +2,9 @@ config SOC_NVIDIA_TEGRA124
 	select ARCH_BOOTBLOCK_ARMV7
 	select ARCH_ROMSTAGE_ARMV7
 	select ARCH_RAMSTAGE_ARMV7
+	select ARM_BOOTBLOCK_CUSTOM
 	bool
 	default n
-	select CPU_HAS_BOOTBLOCK_INIT
 
 if SOC_NVIDIA_TEGRA124
 

src/soc/nvidia/tegra124/Makefile.inc

@@ -1,6 +1,10 @@
 CBOOTIMAGE = cbootimage
 
+bootblock-c-ccopts += -marm
+bootblock-S-ccopts += -marm
+
 bootblock-y += bootblock.c
+bootblock-y += bootblock_asm.S
 bootblock-y += cbfs.c
 bootblock-y += clock.c
 bootblock-y += i2c.c

src/soc/nvidia/tegra124/bootblock.c

@@ -17,8 +17,20 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#include <bootblock_common.h>
+#include <arch/hlt.h>
+#include <arch/stages.h>
+#include <cbfs.h>
+#include <console/console.h>
 
-void bootblock_cpu_init(void)
+void main(void)
 {
+	void *entry;
+
+	if (CONFIG_BOOTBLOCK_CONSOLE)
+		console_init();
+
+	entry = cbfs_load_stage(CBFS_DEFAULT_MEDIA, "fallback/romstage");
+
+	if (entry) stage_exit(entry);
+	hlt();
 }

src/soc/nvidia/tegra124/bootblock_asm.S

@@ -0,0 +1,98 @@
+/*
+ * Early initialization code for ARMv7 architecture.
+ *
+ * This file is based off of the OMAP3530/ARM Cortex start.S file from Das
+ * U-Boot, which itself got the file from armboot.
+ *
+ * Copyright (c) 2004	Texas Instruments <r-woodruff2@ti.com>
+ * Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
+ * Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
+ * Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
+ * Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
+ * Copyright (c) 2003	Kshitij <kshitij@ti.com>
+ * Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
+ * Copyright (c) 2013   The Chromium OS Authors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+.section ".start", "a", %progbits
+.globl _start
+_start: b	reset
+	.balignl 16,0xdeadbeef
+
+_cbfs_master_header:
+	/* The CBFS master header is inserted by cbfstool at the first
+	 * aligned offset after the above anchor string is found.
+	 * Hence, we leave some space for it.
+	 */
+	.skip 128			@ Assumes 64-byte alignment
+
+reset:
+	/*
+	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
+	 * aborts may happen early and crash before the abort handlers are
+	 * installed, but at least the problem will show up near the code that
+	 * causes it.
+	 */
+	msr	cpsr_cxf, #0xdf
+
+	/*
+	 * Initialize the stack to a known value. This is used to check for
+	 * stack overflow later in the boot process.
+	 */
+	ldr	r0, .Stack
+	ldr	r1, .Stack_size
+	sub	r0, r0, r1
+	ldr	r1, .Stack
+	ldr	r2, =0xdeadbeef
+init_stack_loop:
+	str	r2, [r0]
+	add	r0, #4
+	cmp	r0, r1
+	bne	init_stack_loop
+
+/* Set stackpointer in internal RAM to call board_init_f */
+call_bootblock:
+	ldr	sp, .Stack /* Set up stack pointer */
+	ldr	r0,=0x00000000
+	 /*
+	  * The current design of cpu_info places the
+	  * struct at the top of the stack. The number of
+	  * words pushed must be at least as large as that
+	  * struct.
+	  */
+	push	{r0-r2}
+	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
+	/*
+	 * Use "bl" instead of "b" even though we do not intend to return.
+	 * "bl" gets compiled to "blx" if we're transitioning from ARM to
+	 * Thumb. However, "b" will not and GCC may attempt to create a
+	 * wrapper which is currently broken.
+	 */
+	bl	main
+
+/* we do it this way because it's a 32-bit constant and
+ * in some cases too far away to be loaded as just an offset
+ * from IP
+ */
+.align 2
+.Stack:
+	.word CONFIG_STACK_TOP
+.align 2
+/* create this size the same way we do in coreboot_ram.ld: top-bottom */
+.Stack_size:
+	.word CONFIG_STACK_TOP - CONFIG_STACK_BOTTOM