New patch to review for coreboot: qemu/x86: car: drop pointless code, move stack out of the way

[Gerd Hoffmann]

Gerd Hoffmann ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15214

-gerrit

commit b3d987a9b4e0a3013c9b11cdebd4ecfaa5cd7c98
Author: Gerd Hoffmann 
Date:   Thu Jun 16 08:19:59 2016 +0200

qemu/x86: car: drop pointless code, move stack out of the way

RAM doesn't need any initialization on qemu, so we can simply use it
    right away.  No need to try using the cache as ram in the first place.

We also can place the stack in normal ram right from start and we
    don't have to switch it to another place later on.  Place the stack
    in real mode memory which isn't used for something else.

Change-Id: Ib7a3f58a846d139f7babea5f43722a30fe0fe962
    Signed-off-by: Gerd Hoffmann 
---
 src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc b/src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc
index fcd2d3b..ea48112 100644
--- a/src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc
+++ b/src/mainboard/emulation/qemu-i440fx/cache_as_ram.inc
@@ -19,9 +19,6 @@
 #include <cpu/x86/post_code.h>
 #include <cbmem.h>

-#define CACHE_AS_RAM_SIZE 0x10000
-#define CACHE_AS_RAM_BASE 0xd0000
-
 #define CPU_PHYSMASK_HI  (1 << (CONFIG_CPU_ADDR_BITS - 32) - 1)

/* Save the BIST result. */
@@ -29,17 +26,14 @@

cache_as_ram:
    post_code(0x20)
-       /* Clear the cache memory region. This will also fill up the cache */
-	movl	$CACHE_AS_RAM_BASE, %esi
-	movl	%esi, %edi
-	movl	$(CACHE_AS_RAM_SIZE >> 2), %ecx
-	// movl	$0x23322332, %eax
-	xorl	%eax, %eax
-	rep	stosl
+	/*
+	 * No need to cargo-cult cache-as-ram on qemu.
+	 * RAM works just fine without any initialization.
+	 */

post_code(0x21)
-	/* Set up the stack pointer. */
-	movl	$(CACHE_AS_RAM_SIZE + CACHE_AS_RAM_BASE - 4), %eax
+	/* Set up the stack pointer, use top of real mode (640k) memory. */
+	movl	$0xa0000, %eax
    movl	%eax, %esp

/* Restore the BIST result. */
@@ -58,8 +52,6 @@ __main:
    post_code(POST_PREPARE_RAMSTAGE)
    cld			/* Clear direction flag. */

-	movl	$CONFIG_RAMTOP, %esp
-	movl	%esp, %ebp
    call	copy_and_run

.Lhlt: