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rockbox/firmware/target/coldfire/crt0.S
Jens Arnold 81f76f21d6 Fix some comments, and make code consistent with comments (CSMR2 was set to 1M instead of 64K). 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11698 a1c6a512-1295-4272-9138-f99709370657
2006-12-09 11:36:40 +00:00

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ArmAsm
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
.section .init.text,"ax",@progbits
.global start
start:
move.w #0x2700,%sr
move.l #vectors,%d0
movec.l %d0,%vbr
move.l #MBAR+1,%d0
movec.l %d0,%mbar
move.l #MBAR2+1,%d0
movec.l %d0,%mbar2
lea MBAR,%a0
lea MBAR2,%a1
clr.l (0x180,%a1) /* PLLCR = 0 */
/* 64K DMA-capable SRAM at 0x10000000
DMA is enabled and has priority in both banks
All types of accesses are allowed
(We might want to restrict that to save power) */
move.l #0x10000e01,%d0
movec.l %d0,%rambar1
/* 32K Non-DMA SRAM at 0x10010000
All types of accesses are allowed
(We might want to restrict that to save power) */
move.l #0x10010001,%d0
movec.l %d0,%rambar0
/* Chip select 0 - Flash ROM */
moveq.l #0x00,%d0 /* CSAR0 - Base = 0x00000000 */
move.l %d0,(0x080,%a0)
move.l #FLASH_SIZE-0x10000+1,%d0 /* CSMR0 - All access */
move.l %d0,(0x084,%a0)
move.l #0x00000180,%d0 /* CSCR0 - no wait states, 16 bits, no bursts */
move.l %d0,(0x088,%a0)
/* Chip select 1 - LCD controller */
move.l #0xf0000000,%d0 /* CSAR1 - Base = 0xf0000000 */
move.l %d0,(0x08c,%a0)
moveq.l #0x1,%d0 /* CSMR1 - 64K */
move.l %d0,(0x090,%a0)
move.l #0x00000180,%d0 /* CSCR1 - no wait states, 16 bits, no bursts */
move.l %d0,(0x094,%a0)
/* Chip select 2 - ATA controller */
move.l #0x20000000,%d0 /* CSAR2 - Base = 0x20000000 */
move.l %d0,(0x098,%a0)
moveq.l #0x1,%d0 /* CSMR2 - 64K */
move.l %d0,(0x09c,%a0)
move.l #0x00000080,%d0 /* CSCR2 - no wait states, 16 bits, no bursts */
move.l %d0,(0x0a0,%a0) /* wait states are handled by the coldfire
* IDE interface logic. */
#if CONFIG_USBOTG == USBOTG_ISP1362
/* Chip select 3 - USBOTG controller */
move.l #0xc0000000,%d0 /* CSAR3 - Base = 0xc0000000 */
move.l %d0,(0x0a4,%a0)
moveq.l #0x1,%d0 /* CSMR3 - 64K */
move.l %d0,(0x0a8,%a0)
move.l #0x00000180,%d0 /* CSCR3 - no wait states, 16 bits, no bursts */
move.l %d0,(0x0ac,%a0)
#endif
#ifdef BOOTLOADER
/* Check if original firmware is still present */
lea 0x00001000,%a2
move.l (%a2),%d0
move.l #0xfbfbfbf1,%d1
cmp.l %d0,%d1
beq.b .ignorecookie
/* The cookie is not reset. This must mean that the boot loader
has crashed. Let's start the original firmware immediately. */
lea 0x10017ffc,%a2
move.l (%a2),%d0
move.l #0xc0015a17,%d1
cmp.l %d0,%d1
bne.b .nocookie
/* Clear the cookie again */
clr.l (%a2)
jmp 8
.nocookie:
/* Set the cookie */
move.l %d1,(%a2)
.ignorecookie:
/* Set up the DRAM controller. The refresh is based on the 11.2896MHz
clock (5.6448MHz bus frequency). We haven't yet started the PLL */
#if MEM < 32
move.w #0x8004,%d0 /* DCR - Synchronous, 80 cycle refresh */
#else
move.w #0x8001,%d0 /* DCR - Synchronous, 32 cycle refresh */
#endif
move.w %d0,(0x100,%a0)
/* Note on 32Mbyte models:
We place the SDRAM on an 0x1000000 (16M) offset because
the 5249 BGA chip has a fault which disables the use of A24. The
suggested workaround by FreeScale is to offset the base address by
half the DRAM size and increase the mask to the double.
In our case this means that we set the base address 16M ahead and
use a 64M mask.
*/
#if MEM < 32
move.l #0x31002324,%d0 /* DACR0 - Base 0x31000000, Banks on 21 and up,
CAS latency 1, Page mode, No refresh yet */
move.l %d0,(0x108,%a0)
move.l #0x00fc0001,%d0 /* Size: 16M */
move.l %d0,(0x10c,%a0) /* DMR0 - 32Mb */
#else
move.l #0x31002524,%d0 /* DACR0 - Base 0x31000000, Banks on 23 and up,
CAS latency 1, Page mode, No refresh yet */
move.l %d0,(0x108,%a0)
move.l #0x03fc0001,%d0 /* Size: 64M because of workaround above */
move.l %d0,(0x10c,%a0) /* DMR0 - 32Mb */
#endif
/* Precharge */
moveq.l #8,%d0
or.l %d0,(0x108,%a0) /* DACR0[IP] = 1, next access will issue a
Precharge command */
move.l #0xabcd1234,%d0
move.l %d0,0x31000000 /* Issue precharge command */
move.l #0x8000,%d0
or.l %d0,(0x108,%a0) /* Enable refresh */
/* Let it refresh */
move.l #500,%d0
.delayloop:
subq.l #1,%d0
bne.b .delayloop
/* Mode Register init */
moveq.l #0x40,%d0 /* DACR0[IMRS] = 1, next access will set the
Mode Register */
or.l %d0,(0x108,%a0)
move.l #0xabcd1234,%d0
move.l %d0,0x31000800 /* A12=1 means CASL=1 (a0 is not connected) */
/* DACR0[IMRS] gets deactivated by the SDRAM controller */
#endif /* BOOTLOADER */
/* Invalicate cache */
move.l #0x01000000,%d0
movec.l %d0,%cacr
/* Enable cache, default=non-cacheable,no buffered writes */
move.l #0x80000000,%d0
movec.l %d0,%cacr
/* Cache enabled in SDRAM only, buffered writes enabled */
move.l #0x3103c020,%d0
movec.l %d0,%acr0
moveq.l #0,%d0
movec.l %d0,%acr1
#ifndef BOOTLOADER
/* zero out .ibss */
lea _iedata,%a2
lea _iend,%a4
bra.b .iedatastart
.iedataloop:
clr.l (%a2)+
.iedatastart:
cmp.l %a2,%a4
bhi.b .iedataloop
/* copy the .iram section */
lea _iramcopy,%a2
lea _iramstart,%a3
lea _iramend,%a4
bra.b .iramstart
.iramloop:
move.l (%a2)+,(%a3)+
.iramstart:
cmp.l %a3,%a4
bhi.b .iramloop
#endif /* !BOOTLOADER */
#ifdef IRIVER_H300_SERIES
/* Set KEEP_ACT before doing the lengthy copy and zero-fill operations */
move.l #0x00080000,%d0
or.l %d0,(0xb4,%a1)
or.l %d0,(0xb8,%a1)
or.l %d0,(0xbc,%a1)
#endif
/* zero out bss */
lea _edata,%a2
lea _end,%a4
bra.b .edatastart
.edataloop:
clr.l (%a2)+
.edatastart:
cmp.l %a2,%a4
bhi.b .edataloop
/* copy the .data section */
lea _datacopy,%a2
lea _datastart,%a3
cmp.l %a2,%a3
beq.b .nodatacopy /* Don't copy if src and dest are equal */
lea _dataend,%a4
bra.b .datastart
.dataloop:
move.l (%a2)+,(%a3)+
.datastart:
cmp.l %a3,%a4
bhi.b .dataloop
.nodatacopy:
/* Munge the main stack */
lea stackbegin,%a2
lea stackend,%a4
move.l %a4,%sp
move.l #0xdeadbeef,%d0
.mungeloop:
move.l %d0,(%a2)+
cmp.l %a2,%a4
bhi.b .mungeloop
jsr main
.hoo:
bra.b .hoo
.section .resetvectors
vectors:
.long stackend
.long start
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