/* $NetBSD: tsarm_start.S,v 1.7 2011/01/31 06:28:05 matt Exp $ */
/*
* Copyright (c) 2003
* Ichiro FUKUHARA <ichiro@ichiro.org>.
* All rights reserved.
*
* 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 ICHIRO FUKUHARA ``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 ICHIRO FUKUHARA OR THE VOICES IN HIS HEAD 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"
#include <arm/ep93xx/ep93xxreg.h>
RCSID("$NetBSD: tsarm_start.S,v 1.7 2011/01/31 06:28:05 matt Exp $")
.section .start,"ax",%progbits
.global _C_LABEL(ts7xxx_start)
_C_LABEL(ts7xxx_start):
/*
* We will go ahead and disable the MMU here so that we don't
* have to worry about flushing caches, etc.
*
* Note that we may not currently be running VA==PA, which means
* we'll need to leap to the next insn after disabing the MMU.
*/
adr r8, Lunmapped
bic r8, r8, #0xff000000 /* clear upper 8 bits */
/*
* Setup coprocessor 15.
*/
mrc p15, 0, r2, c1, c0, 0
bic r2, r2, #CPU_CONTROL_MMU_ENABLE
mcr p15, 0, r2, c1, c0, 0
nop
nop
nop
mov pc, r8 /* Heave-ho! */
Lunmapped:
/*
* We want to construct a memory map that maps us
* VA==PA (SDRAM at 0x00000000). We create these
* mappings uncached and unbuffered to be safe.
*/
/*
* Step 1: Map the entire address space VA==PA.
*/
adr r4, Ltable
ldr r0, [r4] /* r0 = &l1table */
mov r1, #(L1_TABLE_SIZE / 4) /* 4096 entry */
mov r2, #(L1_S_SIZE) /* 1MB / section */
mov r3, #(L1_S_AP_KRW) /* kernel read/write */
orr r3, r3, #(L1_TYPE_S) /* L1 entry is section */
1:
str r3, [r0], #0x04
add r3, r3, r2
subs r1, r1, #1
bgt 1b
/*
* Step 2: Map VA 0xc0000000->0xc07fffff to PA 0x00000000->0x007fffff.
*/
ldr r0, [r4]
add r0, r0, #(0xc00 * 4) /* offset to 0xc00xxxxx */
mov r1, #0x8 /* 8MB */
mov r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
1:
str r3, [r0], #0x04
add r3, r3, r2
subs r1, r1, #1
bgt 1b
/*
* Step 3: Map VA 0xf0000000->0xf0100000 to PA 0x80000000->0x80100000.
*/
ldr r0, [r4]
add r0, r0, #(0xf00 * 4) /* offset to 0xf0000000 */
mov r3, #0x80000000
orr r3, r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
str r3, [r0], #4
/*
* Step 4: Map VA 0xf0100000->0xf0300000 to PA 0x80800000->0x80a00000.
*/
mov r3, #0x80000000
add r3, r3, #0x00800000
orr r3, r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
str r3, [r0], #0x4
add r3, r3, r2
str r3, [r0], #0x4
/*
* Step 5: Map VA 0xf0300000->0xf4300000 to PA 0x10000000->0x14000000.
*/
mov r1, #0x40 /* 64MB */
mov r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
orr r3, r3, #0x10000000
1:
str r3, [r0], #0x04
add r3, r3, r2
subs r1, r1, #1
bgt 1b
/*
* Step 6: Map VA 0xf4300000->0xf8300000 to PA 0x20000000->0x24000000.
*/
mov r1, #0x40 /* 64MB */
mov r3, #(L1_S_AP_KRW)
orr r3, r3, #(L1_TYPE_S)
orr r3, r3, #0x20000000
1:
str r3, [r0], #0x04
add r3, r3, r2
subs r1, r1, #1
bgt 1b
/* OK! Page table is set up. Give it to the CPU. */
adr r0, Ltable
ldr r0, [r0]
mcr p15, 0, r0, c2, c0, 0
/* Flush the old TLBs, just in case. */
mcr p15, 0, r0, c8, c7, 0
/* Set the Domain Access register. Very important! */
mov r0, #1
mcr p15, 0, r0, c3, c0, 0
/* Get ready to jump to the "real" kernel entry point... */
ldr r1, Lstart
mov r1, r1 /* Make sure the load completes! */
/* OK, let's enable the MMU. */
mrc p15, 0, r2, c1, c0, 0
orr r2, r2, #CPU_CONTROL_MMU_ENABLE
mcr p15, 0, r2, c1, c0, 0
nop
nop
nop
/* CPWAIT sequence to make sure the MMU is on... */
mrc p15, 0, r2, c2, c0, 0 /* arbitrary read of CP15 */
mov r2, r2 /* force it to complete */
mov pc, r1 /* leap to kernel entry point! */
Ltable:
.word 0x4000
Lstart:
.word start