NetBSD-5.0.2/sys/arch/evbarm/gumstix/gumstix_start.S
/* $NetBSD: gumstix_start.S,v 1.5 2007/10/17 19:54:12 garbled Exp $ */
/*
* Copyright (C) 2005, 2006 WIDE Project and SOUM Corporation.
* All rights reserved.
*
* Written by Takashi Kiyohara and Susumu Miki for WIDE Project and SOUM
* 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. Neither the name of the project nor the name of SOUM Corporation
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT and SOUM 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 THE PROJECT AND SOUM 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.
*/
/*
* 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 <arm/arm32/pte.h>
#include <arm/arm32/pmap.h> /* for PMAP_DOMAIN_KERNEL */
#ifndef SDRAM_START
#define SDRAM_START 0xa0000000
#endif
/*
* 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 GUMSTIX
* this code is excuted at the very first after the kernel is loaded
* by U-Boot.
*/
.text
.global _C_LABEL(gumstix_start)
_C_LABEL(gumstix_start):
/* gumstix's loader is u-boot. it's running on RAM */
/*
* Kernel is loaded in SDRAM (0xa0200000..), and is expected to run
* in VA 0xc0200000..
*/
/* save u-boot's args */
adr r0, u_boot_args
nop
nop
nop
stmia r0!, {r3, r4, r5, r6}
nop
nop
nop
/* build page table from scratch */
ldr r0, Lstartup_pagetable /* 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_SYST_ENABLE
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
#ifndef STARTUP_PAGETABLE_ADDR
#define STARTUP_PAGETABLE_ADDR 0xa0000000 /* aligned 16kByte */
#endif
Lstartup_pagetable:
.word STARTUP_PAGETABLE_ADDR
.globl _C_LABEL(u_boot_args)
u_boot_args:
.space 16 /* r3, r4, r5, r6 */
#define MMU_INIT(va,pa,n_sec,attr) \
.word n_sec ; \
.word 4 * ((va) >> L1_S_SHIFT) ; \
.word (pa) | (attr) ;
mmu_init_table:
/* fill all table VA==PA */
MMU_INIT(0x00000000, 0x00000000,
1 << (32 - L1_S_SHIFT), L1_TYPE_S | L1_S_AP(AP_KRW))
/* map SDRAM VA==PA, WT cacheable */
MMU_INIT(SDRAM_START, SDRAM_START,
64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
/* map VA 0xc0000000..0xc3ffffff to PA 0xa0000000..0xa3ffffff */
MMU_INIT(0xc0000000, SDRAM_START,
64, L1_TYPE_S | L1_S_C | L1_S_AP(AP_KRW))
.word 0 /* end of table */