x86: Rename i386 to x86

Signed-off-by: Graeme Russ <graeme.russ@gmail.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/arch/x86/cpu/sc520/sc520_car.S b/arch/x86/cpu/sc520/sc520_car.S
new file mode 100644
index 0000000000..a33f94f491
--- /dev/null
+++ b/arch/x86/cpu/sc520/sc520_car.S
@@ -0,0 +1,93 @@
+/*
+ * (C) Copyright 2010-2011
+ * Graeme Russ, <graeme.russ@gmail.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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
+ */
+
+#include <config.h>
+#include <asm/processor-flags.h>
+#include <asm/ic/sc520.h>
+
+.section .text
+
+.globl car_init
+car_init:
+	/*
+	 * How to enable Cache-As-RAM for the AMD Elan SC520:
+	 *  1. Turn off the CPU Cache (may not be strictly required)
+	 *  2. Set code execution PAR (usually the BOOTCS region) to be
+	 *     non-cachable
+	 *  3. Create a Cachable PAR Region for an area of memory which is
+	 *       a) NOT where the code is being executed
+	 *       b) NOT SDRAM (Controller not initialised yet)
+	 *       c) WILL response to read requests
+	 *     The easiest way to do this is to create a second BOOTCS
+	 *     PAR mappnig with an address != the PAR in step 2
+	 *  4. Issue a wbinvd to invalidate the CPU cache
+	 *  5. Turn on the CPU Cache
+	 *  6. Read 16kB from the cached PAR region setup in step 3
+	 *  7. Turn off the CPU Cache (but DO NOT issue a wbinvd)
+	 *
+	 * The following code uses PAR2 as the cached PAR (PAR0 and PAR1
+	 * are avoided as these are the only two PARs which can be used
+	 * as PCI BUS Memory regions which the board might require)
+	 *
+	 * The configuration of PAR2 must be set in the board configuration
+	 * file as CONFIG_SYS_SC520_CAR_PAR
+	 */
+
+	/* Configure Cache-As-RAM PAR */
+	movl	$CONFIG_SYS_SC520_CAR_PAR, %eax
+	movl	$SC520_PAR2, %edi
+	movl	%eax, (%edi)
+
+	/* Trash the cache then turn it on */
+	wbinvd
+	movl	%cr0, %eax
+	andl	$~(X86_CR0_NW | X86_CR0_CD), %eax
+	movl	%eax, %cr0
+
+	/*
+	 * The cache is now enabled and empty. Map a region of memory to
+	 * it by reading that region.
+	 */
+	movl	$CONFIG_SYS_CAR_ADDR, %esi
+	movl	$CONFIG_SYS_CAR_SIZE, %ecx
+	shrl	$2, %ecx			/* we are reading longs */
+	cld
+	rep	lodsl
+
+	/* Turn off the cache, but don't trash it */
+	movl	%cr0, %eax
+	orl	$(X86_CR0_NW | X86_CR0_CD), %eax
+	movl	%eax, %cr0
+
+	/* Clear the CAR region */
+	xorl	%eax, %eax
+	movl	$CONFIG_SYS_CAR_ADDR, %edi
+	movl	$CONFIG_SYS_CAR_SIZE, %ecx
+	shrl	$2, %ecx			/* we are writing longs */
+	rep	stosl
+
+	/*
+	 * Done - We should now have CONFIG_SYS_CAR_SIZE bytes of
+	 * Cache-As-RAM
+	 */
+	jmp	car_init_ret