NetBSD/sys/arch/evbarm/integrator/intmmu.S

206 lines
5.5 KiB
ArmAsm

/* $NetBSD: intmmu.S,v 1.11 2011/01/31 06:28:03 matt Exp $ */
/*
* Copyright (c) 2001 ARM Ltd
* 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.
* 3. The name of the company may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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"
.section .start,"ax",%progbits
ASENTRY_NP(integrator_start)
mov r6, #0x16000000 /* UART0 Physical base*/
#ifdef VERBOSE_INIT_ARM
mov r3, #'A'
str r3, [r6] /* Let the world know we are alive */
#endif
/*
* Check that the processor has a CP15. Some core modules do not.
* We can tell by reading CM_PROC. If it is zero, then we're OK, otherwise
* let the user know why we've died.
*/
mov r7, #0x10000000
ldr r3, [r7, #4]
cmp r3, #0
bne Lno_cp15
/*
* Now read CP15 and check what sort of core we have. We need to know
* if it has an MMU. There's no simple test for this, but the following
* hack should be sufficient for all currently supported CM boards:
* - Check that the product code has a '2' or '3' in bits 8-11
*/
mrc p15, 0, r3, c0, c0, 0
and r0, r3, #0x00000f00
teq r0, #0x00000200 /* ARM 920, 1020, 1026, etc */
teqne r0, #0x00000300 /* ARM 1136 */
bne Lno_mmu
/*
* At this time the MMU is off.
* We build up an initial memory map at 0x8000 that we can use to get
* the kernel running from the top of memory. All mappings in this table
* use L1 section maps.
*/
/*
* Set Virtual == Physical
*/
mov r3, #(L1_S_AP_KRW)
add r3, r3, #(L1_TYPE_S)
mov r2, #0x100000 /* advance by 1MB */
mov r1, #0x8000 /* page table start */
mov r0, #0x1000 /* page table size */
Lflat:
str r3, [r1], #0x0004
add r3, r3, r2
subs r0, r0, #1
bgt Lflat
/*
* Map VA 0xc0000000->0xc03fffff to PA 0x00000000->0x003fffff
*/
mov r3, #(L1_S_AP_KRW)
add r3, r3, #(L1_TYPE_S)
mov r1, #0x8000 /* page table start */
add r1, r1, #(0xc00 * 4) /* offset to 0xc00xxxxx */
# add r1, r1, #(0x001 * 4) /* offset to 0xc01xxxxx */
mov r0, #63
Lkern:
str r3, [r1], #0x0004 /* 0xc000000-0xc03fffff */
add r3, r3, r2
subs r0, r0, #1
bgt Lkern
/*
* Mapping the peripheral register region (0x10000000->0x1fffffff) linearly
* would require 256MB of virtual memory (as much space as the entire kernel
* virtual space). So we map the first 1M of each 16MB sub-space into the
* region VA 0xfd000000->0xfdffffff; this should map enough of the peripheral
* space to at least get us up and running.
*/
mov r3, #(L1_S_AP_KRW)
add r3, r3, #L1_TYPE_S
add r3, r3, #0x10000000 /* Peripherals base */
mov r1, #0x8000 /* page table start */
add r1, r1, #(0xfd0 * 4)
mov r2, #0x01000000 /* 16MB increment. */
mov r0, #16
Lperiph:
str r3, [r1], #4 /* 0xfd000000-0xfdffffff */
add r3, r3, r2
subs r0, r0, #1
bgt Lperiph
/*
* We now have our page table ready, so load it up and light the blue
* touch paper.
*/
/* set the location of the L1 page table */
mov r1, #0x8000
mcr p15, 0, r1, c2, c0, 0
/* Flush the old TLBs (just in case) */
mcr p15, 0, r1, c8, c7, 0
/* And the caches */
mov r0, #0
mcr p15, 0, r1, c7, c6, 0
#ifdef VERBOSE_INIT_ARM
mov r2, #'B'
strb r2, [r6]
#endif
/* Set the Domain Access register. Very important! */
mov r1, #1
mcr p15, 0, r1, c3, c0, 0
/*
* set mmu bit (don't set anything else for now, we don't know
* what sort of CPU we have yet.
*/
mov r1, #CPU_CONTROL_MMU_ENABLE
/*
* This is where it might all start to go wrong if the CPU fitted to your
* integrator does not have an MMU.
*/
/* fetch current control state */
mrc p15, 0, r2, c1, c0, 0
orr r2, r2, r1
/* set new control state */
mcr p15, 0, r2, c1, c0, 0
mov r0, r0
mov r0, r0
mov r0, r0
#ifdef VERBOSE_INIT_ARM
/* emit a char. Uart is now at 0xfd600000 */
mov r6, #0xfd000000
add r6, r6, #0x00600000
mov r2, #'C'
strb r2, [r6]
#endif
/* jump to kernel space */
mov r0, #0x0200
/* Switch to kernel VM and really set the ball rolling. */
ldr pc, Lstart
Lstart: .long start
Lmsg:
ldrb r2, [r0], #1
cmp r2, #0
strneb r2, [r6]
Lwait:
ldrb r3, [r6, #0x18]
tst r3, #0x80
beq Lwait
cmp r2, #0
bne Lmsg
/* We're toast! */
b .
Lno_cp15:
adr r0, Lcp15msg
b Lmsg
Lno_mmu:
adr r0, Lmmumsg
b Lmsg
Lcp15msg:
.ascii "Core has no cp15\r\n\0"
Lmmumsg:
.ascii "Core has no MMU\r\n\0"