freebsd-skq/sys/powerpc/wii/locore.S
adrian 4172690a5e Setup BAT0 and BAT1 on the Wii.
This is the missing piece for FreeBSD/Wii, but there's still a lot of
work ahead. We have to reset the MMU in locore before continuing
the boot process because we don't know how the boot loaders might
have setup the BATs. We also disable the PCI BAT because there's no PCI
bus on the Wii.

Thanks to Nathan Whitehorn and Peter Grenhan for their help.

Submitted by:	Margarida Gouveia
2012-11-21 08:04:21 +00:00

132 lines
3.4 KiB
ArmAsm

/*-
* Copyright (C) 2012 Margarida Gouveia
* 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 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 TOOLS GMBH 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.
*
* $FreeBSD$
*/
#include <machine/bat.h>
/*
* When we are invoked from Wii loaders, the state of the MMU and the BAT
* mappings can vary. In this file we try to reset the MMU to a state
* that lets us boot FreeBSD.
*
* N.B.: keep the BAT0 in sync with mmu_oea.c and never touch BAT1 later.
*
* This file is being included from aim/locore32.S.
*/
#define MMU_REALMODE() \
mfmsr %r12; \
rlwinm %r12, %r12, 0, ~(PSL_DR|PSL_IR);\
sync; \
bl 1f; \
1: \
mflr %r11; \
clrlwi %r11, %r11, 3; /* XXX why? */ \
addi %r11, %r11, 2f - 1b; \
mtsrr0 %r11; \
mtsrr1 %r12; /* Disables the MMU */ \
isync; \
rfi; \
2:
#define MMU_VIRTUALMODE() \
bl 3f; \
3: \
mflr %r11; \
addi %r11, %r11, 4f - 3b; \
mfmsr %r12; \
ori %r12, %r12, PSL_DR|PSL_IR; \
mtsrr0 %r11; \
mtsrr1 %r12; /* Enables the MMU */ \
isync; \
rfi; \
4:
MMU_REALMODE()
/* Reset standard BATs */
li %r11, 0
mtibatu 0, %r11
mtibatl 0, %r11
mtdbatu 0, %r11
mtdbatl 0, %r11
mtibatu 1, %r11
mtibatl 1, %r11
mtdbatu 1, %r11
mtdbatl 1, %r11
mtibatu 2, %r11
mtibatl 2, %r11
mtdbatu 2, %r11
mtdbatl 2, %r11
mtibatu 3, %r11
mtibatl 3, %r11
mtdbatu 3, %r11
mtdbatl 3, %r11
/* Reset high BATs. IBAT[4-7][UL] + DBAT[4-7][UL] */
mtspr 560, %r11
mtspr 561, %r11
mtspr 562, %r11
mtspr 563, %r11
mtspr 564, %r11
mtspr 565, %r11
mtspr 566, %r11
mtspr 567, %r11
mtspr 568, %r11
mtspr 569, %r11
mtspr 570, %r11
mtspr 571, %r11
mtspr 572, %r11
mtspr 573, %r11
mtspr 574, %r11
mtspr 575, %r11
/*
* We need to setup BAT0 as in mmu_oea.c.
*/
li %r11, BATU(0x00000000, BAT_BL_256M, BAT_Vs)
li %r12, BATL(0x00000000, BAT_M, BAT_PP_RW)
mtdbatu 0, %r11
mtdbatl 0, %r12
mtibatu 0, %r11
mtibatl 0, %r12
isync
/*
* We use BAT1 to be able to write I/O memory, including the
* framebuffer registers.
*/
/* BATU(0x0c000000, BAT_BL_32M, BAT_Vs) */
lis %r11, 0x0c00
ori %r11, %r11, BAT_BL_32M|BAT_Vs
/* BATL(0x0c000000, BAT_I|BAT_G, BAT_PP_RW) */
lis %r12, 0x0c00
ori %r12, %r12, BAT_I|BAT_G|BAT_PP_RW
mtdbatu 1, %r11
mtdbatl 1, %r12
isync
MMU_VIRTUALMODE()