* mpcsa_start.S

/*
* mpcsa_start.S
* Copyright (c) 2007, S. Kantoluoto <[email protected]>
* All rights reserved.
*
* Based on vx115_vep_start.S
* Copyright (c) 2007, J. Sevy <[email protected]>
*
* Based on g42xxeb_start.S
* Copyright (c) 2002, 2003 Genetec Corporation. All rights reserved.
* Written by Hiroyuki Bessho for Genetec Corporation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of Genetec Corporation may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GENETEC CORPORATION
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <machine/asm.h>
#include <arm/armreg.h>
#include "assym.h"

RCSID("$NetBSD: mpcsa_start.S,v 1.3 2011/01/31 06:28:04 matt Exp $")

#ifndef FLASH_START
#define FLASH_START 0x10020000
#endif

#ifndef SDRAM_START
#define SDRAM_START 0x20000000
#endif

#define MODBASE 0x20200000

/*
* CPWAIT -- Canonical method to wait for CP15 update.
* NOTE: Clobbers the specified temp reg.
* copied from arm/arm/cpufunc_asm_xscale.S
* XXX: better be in a common header file.
*/
#define CPWAIT_BRANCH \
sub pc, pc, #4

#define CPWAIT(tmp) \
mrc p15, 0, tmp, c2, c0, 0 /* arbitrary read of CP15 */ ;\
mov tmp, tmp /* wait for it to complete */ ;\
CPWAIT_BRANCH /* branch to next insn */

/*
* Kernel start routine for MPCSA board.
* This code is executed from Flash when the bootloader jumps to it.
*/
.text

.global _C_LABEL(mpcsa_start)
_C_LABEL(mpcsa_start):

/* make sure we're in supervisor mode */
mov r0,sp
msr CPSR_c,#I32_bit | F32_bit | PSR_SVC32_MODE
mov sp,r0

/* move code to RAM */
ldr r1, Lcopy_size
adr r0, _C_LABEL(mpcsa_start)
add r1, r1, #3
mov r1, r1, LSR #2 /* get size of code in words */
mov r2, #SDRAM_START
add r2, r2, #0x200000 /* code placed 2MB above kernel base */
mov r4, r2

/* copy kernel to RAM */
5: ldr r3, [r0], #4
subs r1, r1, #1
str r3, [r2], #4
bhi 5b

/* jump to RAM */
ldr r0, Lstart_off
add pc, r4, r0

Lcopy_size: .word _edata-_C_LABEL(mpcsa_start)
Lstart_off: .word mpcsa_start_ram-_C_LABEL(mpcsa_start)

mpcsa_start_ram:
/*
* Kernel is loaded in SDRAM (0x20200000), and is expected to run
* in VA 0xc0200000.
*/

/* build page table from scratch */
ldr r0, Lstartup_pagetable
adr r4, mmu_init_table
b 3f

2:
str r3, [r0, r2]
add r2, r2, #4
add r3, r3, #(L1_S_SIZE)
adds r1, r1, #-1
bhi 2b
3:
ldmia r4!, {r1,r2,r3} /* # of sections, PA|attr, VA */
cmp r1, #0
bne 2b

mcr p15, 0, r0, c2, c0, 0 /* Set TTB */
mcr p15, 0, r0, c8, c7, 0 /* Flush TLB */

/* Set the Domain Access register. Very important! */
mov r0, #((DOMAIN_CLIENT << (PMAP_DOMAIN_KERNEL*2)) | DOMAIN_CLIENT)
mcr p15, 0, r0, c3, c0, 0

/* Enable MMU */
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #CPU_CONTROL_MMU_ENABLE
mcr p15, 0, r0, c1, c0, 0
CPWAIT(r0)

/* Jump to kernel code in TRUE VA */
adr r0, Lstart
ldr pc, [r0]

Lstart:
.word start

#define MMU_INIT(va,pa,n_sec,attr) \
.word n_sec ;\
.word 4*((va)>>L1_S_SHIFT) ;\
.word (pa) | (attr)

#define STARTUP_PAGETABLE_ADDR 0x20100000 + 0x4000

Lstartup_pagetable:
.word STARTUP_PAGETABLE_ADDR

mmu_init_table:
/* fill all table VA==PA */
MMU_INIT(0x00000000, 0x00000000, 1<<(32-L1_S_SHIFT), L1_TYPE_S|L1_S_AP_KRW)
/* map in peripheral space */
MMU_INIT(0xfff00000, 0xfff00000, 1, L1_TYPE_S|L1_S_AP_KRW)
/* map SDRAM VA==PA, WT cacheable */
MMU_INIT(0x20100000, 0x20100000, 63, L1_TYPE_S|L1_S_C|L1_S_AP_KRW)
/* map VA 0xc0000000..0xc0efffff to PA 0x20100000..0x23ffffff */
MMU_INIT(0xc0000000, 0x20000000, 63, L1_TYPE_S|L1_S_C|L1_S_AP_KRW)
.word 0 /* end of table */

.align 7
jme_module_header:
.word 0xe990510e /* magic number */
.string "NetBSD/mpcsa\0\0\0" /* module name */
.short 0 /* build flags */
.short 0 /* flags */
.word 0 /* version */
.word 0 /* compile / link timestamp */
.word MODBASE /* pointer to init routine */
.word MODBASE /* start address */
.word (_edata-(_C_LABEL(mpcsa_start))) /* length of module */
.word (jme_module_header-_C_LABEL(mpcsa_start)+MODBASE) /* back pointer to module struct*/
.word 0 /* data pointer (ignored but SBZ)*/
.word 0 /* data length (ignored but SBZ)*/
.word 0x20200000 /* alternate address */
.word 0 /* reserved, SBZ */

jme_kmodule_header:
.word 0xe000301e /* magic number */
.string "JME kernel\0\0\0\0\0" /* module name */
.short 0 /* build flags */
.short 0 /* flags */
.word 0 /* version */
.word 0 /* compile / link timestamp */
.word MODBASE /* pointer to init routine */
.word MODBASE /* start address */
.word (_edata-(_C_LABEL(mpcsa_start))) /* length of module */
.word (jme_kmodule_header-_C_LABEL(mpcsa_start)+MODBASE) /* back pointer to module struct*/
.word 0 /* data pointer (ignored but SBZ)*/
.word 0 /* data length (ignored but SBZ)*/
.word 0x20200000 /* alternate address */
.word 0 /* reserved, SBZ */