Commit 57f5029b authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] m68knommu: add start code for COBRA5282 board

From: <gerg@snapgear.com>

Add start up code specific to the newly added COBRA5282 board.
parent deb09fa2
/*****************************************************************************/
/*
* crt0_ram.S -- startup code for MCF5282 ColdFire based boards.
*
* (C) Copyright 2003, Greg Ungerer (gerg@snapgear.com).
*/
/*****************************************************************************/
#include <linux/config.h>
#include <linux/threads.h>
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/coldfire.h>
#include <asm/mcfsim.h>
/*****************************************************************************/
/*
* senTec COBRA5282 board, chip select and memory setup.
*/
#define MEM_BASE 0x00000000 /* Memory base at address 0 */
#define VBR_BASE MEM_BASE /* Vector address */
#if defined(CONFIG_RAM16MB)
#define MEM_SIZE 0x01000000 /* Memory size 16Mb */
#elif defined(CONFIG_RAM8MB)
#define MEM_SIZE 0x00800000 /* Memory size 8Mb */
#else
#define MEM_SIZE 0x00400000 /* Memory size 4Mb */
#endif
#define IPSBAR 0x40000000
#define GPACR0 0x30
/*****************************************************************************/
.global _start
.global _rambase
.global _ramvec
.global _ramstart
.global _ramend
/*****************************************************************************/
.data
/*
* Set up the usable of RAM stuff. Size of RAM is determined then
* an initial stack set up at the end.
*/
_rambase:
.long 0
_ramvec:
.long 0
_ramstart:
.long 0
_ramend:
.long 0
/*****************************************************************************/
.text
/*
* This is the codes first entry point. This is where it all
* begins...
*/
_start:
nop /* Filler */
move.w #0x2700, %sr /* No interrupts */
/*
* Setup VBR here, otherwise buserror remap will not work.
* if dBug was active before (on my SBC with dBug 1.1 of Dec 16 1996)
*
* bkr@cut.de 19990306
*
* Note: this is because dBUG points VBR to ROM, making vectors read
* only, so the bus trap can't be changed. (RS)
*/
move.l #VBR_BASE, %a7 /* Note VBR can't be read */
movec %a7, %VBR
move.l %a7, _ramvec /* Set up vector addr */
move.l %a7, _rambase /* Set up base RAM addr */
/*
* Set memory size.
*/
move.l #MEM_SIZE, %a0
move.l %a0, %d0 /* Mem end addr is in a0 */
move.l %d0, %sp /* Set up initial stack ptr */
move.l %d0, _ramend /* Set end ram addr */
/*
* Enable CPU internal cache.
*
* Cache is totally broken in first 5282 silicon.
* No point enabling it for now.
*/
#if 0
move.l #0x01000000, %d0
movec %d0, %CACR /* Invalidate cache */
nop
move.l #0x0000c000, %d0 /* Set SDRAM cached only */
movec %d0, %ACR0
move.l #0x00000000, %d0 /* No other regions cached */
movec %d0, %ACR1
move.l #0x00000000, %d0 /* Setup cache mask */
movec %d0, %CACR /* Enable cache */
nop
#endif
#ifdef CONFIG_ROMFS_FS
/*
* Move ROM filesystem above bss :-)
*/
lea.l _sbss, %a0 /* Get start of bss */
lea.l _ebss, %a1 /* Set up destination */
move.l %a0, %a2 /* Copy of bss start */
move.l 8(%a0), %d0 /* Get size of ROMFS */
addq.l #8, %d0 /* Allow for rounding */
and.l #0xfffffffc, %d0 /* Whole words */
add.l %d0, %a0 /* Copy from end */
add.l %d0, %a1 /* Copy from end */
move.l %a1, _ramstart /* Set start of ram */
_copy_romfs:
move.l -(%a0), %d0 /* Copy dword */
move.l %d0, -(%a1)
cmp.l %a0, %a2 /* Check if at end */
bne _copy_romfs
#else /* CONFIG_ROMFS_FS */
lea.l _ebss, %a1
move.l %a1, _ramstart
#endif /* CONFIG_ROMFS_FS */
/*
* Zero out the bss region.
*/
lea.l _sbss, %a0 /* Get start of bss */
lea.l _ebss, %a1 /* Get end of bss */
clr.l %d0 /* Set value */
_clear_bss:
move.l %d0, (%a0)+ /* Clear each word */
cmp.l %a0, %a1 /* Check if at end */
bne _clear_bss
/*
* Load the current thread pointer and stack.
*/
lea init_thread_union, %a0
lea 0x2000(%a0), %sp
/*
* User mode port access
*/
move.l #0x0000000c, %d0
move.b %d0, (IPSBAR+GPACR0)
/*
* Assember start up done, start code proper.
*/
jsr start_kernel /* Start Linux kernel */
_exit:
jmp _exit /* Should never get here */
/*****************************************************************************/
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