coreboot t132: Stack init re-work

1) In order to avoid stack from overflowing during ramstage decompression,
initialize stack right at the beginning of romstage.
2) Declare different Kconfig options for stack at each stage.
3) Provide a macro that does stack seeding if required and calls appropriate
function.

BUG=None
BRANCH=None
TEST=Compiles and runs successfully on rush.

Original-Change-Id: I55d6ce59ea91affba3e86d68406921497c83fb52
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/206880
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
(cherry picked from commit 5e32d73803a2a9d222fcc4ca5f58efd3abe95d34)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Ib833a1badb170a33cbf20d232019425b59db60cd
Reviewed-on: http://review.coreboot.org/8583
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/src/soc/nvidia/tegra132/stack.S b/src/soc/nvidia/tegra132/stack.S
new file mode 100644
index 0000000000..6d3cd4e446
--- /dev/null
+++ b/src/soc/nvidia/tegra132/stack.S
@@ -0,0 +1,47 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* Macro to initialize stack, perform seeding if required and finally call the
+ * function provided
+ * @stack : Stack address
+ * @size  : Stack size
+ * @seed  : Stack seeding required (1=yes/otherwise=no)
+ * @func  : Function to call after initializing stack
+ */
+.macro stack_init stack, size, seed, func
+        /* Check if stack seeding is required */
+	mov	r0, #\seed
+	cmp     r0, #1
+	bne     call_func
+	/* Stack seeding */
+	ldr     r0, \stack
+	ldr	r1, \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
+
+call_func:
+	ldr	sp, \stack /* Set up stack pointer */
+	bl	\func
+.endm