netbsd/sys/arch/evbarm/imx31/imx31lk_start.S
2013-04-06 16:48:33 +02:00

157 lines
4.2 KiB
ArmAsm

/* $NetBSD: imx31lk_start.S,v 1.4 2011/01/31 06:28:03 matt Exp $ */
/*-
* Copyright (c) 2011 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas of 3am Software Foundry.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``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 FOUNDATION OR CONTRIBUTORS
* 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: imx31lk_start.S,v 1.4 2011/01/31 06:28:03 matt Exp $")
/*
*/
#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 */
#ifndef SDRAM_START
#define SDRAM_START 0x80000000
#endif
#define IMX31_DCACHE_SIZE 0x4000 /* 16KB L1 */
/*
* L1 == "Level One" == "first-level"
* L2 == "Level Two" == "second-level"
*/
.text
.global _C_LABEL(imx31lk_start)
_C_LABEL(imx31lk_start):
/* Figure out where we want to jump to when the time comes */
adr r8, .Lstart
ldr r8, [r8]
/*
* set up virtual address space mapping
* for initial bootstrap.
*/
mov r2, #(L1_S_SIZE) /* 1MB chunks */
/*
* Firmware already mapped SDRAM VA == PA. at 0x800..
* now map SDRAM also at VA 0x800...
*/
mrc p15, 0, r0, c2, c0, 0 /* L1 table addr into r0 */
add r0, r0, #(0x800 * 4) /* offset to 0x80000000 */
mov r3, #SDRAM_START /* map to 0x800.. */
orr r3, r3, #(L1_S_AP_KRW) /* the usual perms & stuff */
orr r3, r3, #(L1_TYPE_S)
orr r3, r3, #(L1_S_DOM_KERNEL)
mov r1, #0x80 /* 128 1MB entries */
1:
/* and looplooploop */
str r3, [r0], #4
add r3, r3, r2
subs r1, r1, #1
bgt 1b
/*
* Map an L1 section for each device to make this easy.
*/
/* UART1 */
mrc p15, 0, r0, c2, c0, 0 /* L1 table addr into r0 */
add r0, r0, #(0xfd0 * 4) /* offset to 0xfd000000 */
mov r3, #0x43000000
orr r3, r3, #0x00f00000
orr r3, r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
orr r3, r3, #(L1_S_DOM_KERNEL)
str r3, [r0], #4 /* note autoinc */
/* etc, TBD... */
/*
* Make domain control go full art.
*/
mov r0, #0xffffffff
mcr p15, 0, r0, c3, c0, 0
/*
* Now let's clean the cache again to make sure everything
* is in place.
*
* XXX: should this take into account the XScale cache clean bug?
*/
mov r3, #(IMX31_DCACHE_SIZE)
subs r3, r3, #32
1:
mcr p15, 0, r3, c7, c10, 2
subs r3, r3, #32
bne 1b
CPWAIT(r3)
/* Drain write buffer */
mcr p15, 0, r6, c7, c10, 4
/* Invalidate TLBs just to be sure */
mcr p15, 0, r0, c8, c7, 0
/*
* You are standing at the gate to NetBSD. --More--
* Unspeakable cruelty and harm lurk down there. --More--
* Are you sure you want to enter?
*/
adr r8, .Lstart
ldr r8, [r8]
mov pc, r8 /* So be it */
/* symbol to use for address calculation in the right VA */
.Lstart:
.word start
/*
* Calculate size of kernel to copy. Don't bother to copy bss,
* although I guess the CPU could use the warmup exercise ...
*/
.Lcopy_size:
.word _edata - _C_LABEL(imx31lk_start)