source: mainline/arch/ppc64/loader/asm.S@ a8844e0

#
# Copyright (C) 2006 Martin Decky
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - 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.
# - The name of the author 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 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 "asm.h"
#include "regname.h"

.text

.global halt
.global memcpy
.global jump_to_kernel

halt:
        b halt

memcpy:
        srwi. r7, r5, 3
        addi r6, r3, -4
        addi r4, r4, -4
        beq     2f
        
        andi. r0, r6, 3
        mtctr r7
        bne 5f
        
        1:
        
        lwz r7, 4(r4)
        lwzu r8, 8(r4)
        stw r7, 4(r6)
        stwu r8, 8(r6)
        bdnz 1b
        
        andi. r5, r5, 7
        
        2:
        
        cmplwi 0, r5, 4
        blt 3f
        
        lwzu r0, 4(r4)
        addi r5, r5, -4
        stwu r0, 4(r6)
        
        3:
        
        cmpwi 0, r5, 0
        beqlr
        mtctr r5
        addi r4, r4, 3
        addi r6, r6, 3
        
        4:
        
        lbzu r0, 1(r4)
        stbu r0, 1(r6)
        bdnz 4b
        blr
        
        5:
        
        subfic r0, r0, 4
        mtctr r0
        
        6:
        
        lbz r7, 4(r4)
        addi r4, r4, 1
        stb r7, 4(r6)
        addi r6, r6, 1
        bdnz 6b
        subf r5, r0, r5
        rlwinm. r7, r5, 32-3, 3, 31
        beq 2b
        mtctr r7
        b 1b


jump_to_kernel:
        
        # r3 = bootinfo (pa)
        # r4 = bootinfo_size
        # r5 = trans (pa)
        # r6 = kernel size
        # r7 = framebuffer (pa)
        # r8 = real_mode (pa)
        
        mtspr srr0, r8
        
        # jumps to real_mode
        
        mfmsr r31
        lis r30, ~0@h
        ori r30, r30, ~(msr_ir | msr_dr)@l
        and r31, r31, r30
        mtspr srr1, r31
        
        sync
        isync
        rfid

.section REALMODE
.align PAGE_WIDTH
.global real_mode

real_mode:
        
        # copy kernel to proper location
        #
        # r5 = trans (pa)
        # r6 = kernel size
        # r7 = framebuffer (pa)
        
        li r31, PAGE_SIZE >> 2
        li r30, 0
        
        page_copy:
                
                cmpwi r6, 0
                beq copy_end
                
                # copy page
                
                mtctr r31
                lwz r29, 0(r5)
                
                copy_loop:
                        
                        lwz r28, 0(r29)
                        stw r28, 0(r30)
                        
                        addi r29, r29, 4
                        addi r30, r30, 4
                        subi r6, r6, 4
                        
                        cmpwi r6, 0
                        beq copy_end
                        
                        bdnz copy_loop
                
                addi r5, r5, 4
                b page_copy
        
        copy_end:
        
        # invalidate segment registers

        li r31, 16
        mtctr r31
        li r31, 0
        li r30, 0

        seg_fill:
        
                mtsrin r30, r31
                addis r31, r31, 0x1000    # move to next SR
                
                bdnz seg_fill
        
        # invalidate block address translation registers
        
        mtspr ibat0u, r30
        mtspr ibat0l, r30
        
        mtspr ibat1u, r30
        mtspr ibat1l, r30
        
        mtspr ibat2u, r30
        mtspr ibat2l, r30
        
        mtspr ibat3u, r30
        mtspr ibat3l, r30
        
        mtspr dbat0u, r30
        mtspr dbat0l, r30
        
        mtspr dbat1u, r30
        mtspr dbat1l, r30
        
        mtspr dbat2u, r30
        mtspr dbat2l, r30
        
        mtspr dbat3u, r30
        mtspr dbat3l, r30
        
        # create identity mapping
        
        # FIXME: map exactly the size of RAM
        
        lis r31, 0x8000
        ori r31, r31, 0x0ffe
        
        lis r30, 0x0000
        ori r30, r30, 0x0002
        
        mtspr ibat0u, r31
        mtspr ibat0l, r30
        
        mtspr dbat0u, r31
        mtspr dbat0l, r30
        
        # FIXME: temporal framebuffer mapping
        
        lis r31, 0xf000
        ori r31, r31, 0x0ffe
        
        mr r30, r7
        ori r30, r30, 0x0002
        
        mtspr dbat1u, r31
        mtspr dbat1l, r30
        
        tlbia
        
        # start the kernel
        #
        # r3 = bootinfo (pa)
        
        lis r31, KERNEL_START_ADDR@ha
        addi r31, r31, KERNEL_START_ADDR@l
        
        mtspr srr0, r31
        
        mfmsr r31
        ori r31, r31, (msr_ir | msr_dr)@l
        mtspr srr1, r31
        
        sync
        isync
        rfid

.align PAGE_WIDTH
.global trans
trans:
        .space (TRANS_SIZE * TRANS_ITEM_SIZE)