source: mainline/arch/ppc32/src/asm.S@ 0f27b4c

#
# Copyright (C) 2005 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,
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# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include <arch/asm/regname.h>

.text

.global userspace_asm
.global iret
.global memsetb
.global memcpy

userspace_asm:

        # r3 = uspace_uarg
        # r4 = stack
        # r5 = entry    

        mfmsr r31
        rlwinm r31, r31, 0, 17, 15
        mtmsr r31
        
        # set entry point
        
        mtsrr0 r5
        
        # set problem state, enable interrupts
        
        ori r31, r31, 1 << 14
        ori r31, r31, 1 << 15
        mtsrr1 r31
        
        # set stack
        
        mr sp, r4
        
        # jump to userspace
        
        rfi

iret:
        lwz r3, 144(sp)
        mtxer r3
        
        lwz r3, 140(sp)
        mtctr r3
        
        lwz r3, 136(sp)
        mtcr r3
        
        lwz r3, 132(sp)
        mtlr r3
        
        lwz r3, 128(sp)
        mtspr srr1, r3
        
        lwz r3, 124(sp)
        mtspr srr0, r3
        
        lwz r0, 0(sp)
        lwz r2, 4(sp)
        lwz r3, 8(sp)
        lwz r4, 12(sp)
        lwz r5, 16(sp)
        lwz r6, 20(sp)
        lwz r7, 24(sp)
        lwz r8, 28(sp)
        lwz r9, 32(sp)
        lwz r10, 36(sp)
        lwz r11, 40(sp)
        lwz r12, 44(sp)
        lwz r13, 48(sp)
        lwz r14, 52(sp)
        lwz r15, 56(sp)
        lwz r16, 60(sp)
        lwz r17, 64(sp)
        lwz r18, 68(sp)
        lwz r19, 72(sp)
        lwz r20, 76(sp)
        lwz r21, 80(sp)
        lwz r22, 84(sp)
        lwz r23, 88(sp)
        lwz r24, 92(sp)
        lwz r25, 96(sp)
        lwz r26, 100(sp)
        lwz r27, 104(sp)
        lwz r28, 108(sp)
        lwz r29, 112(sp)
        lwz r30, 116(sp)
        lwz r31, 120(sp)
        
        mfspr sp, sprg1
        
        rfi
        
memsetb:
        rlwimi r5, r5, 8, 16, 23
        rlwimi r5, r5, 16, 0, 15
        
        addi r14, r3, -4
        
        cmplwi 0, r4, 4
        blt 7f
        
        stwu r5, 4(r14)
        beqlr
        
        andi. r15, r14, 3
        add r4, r15, r4
        subf r14, r15, r14
        srwi r15, r4, 2
        mtctr r15
        
        bdz 6f
        
        1:
                stwu r5, 4(r14)
                bdnz 1b
        
        6:
        
        andi. r4, r4, 3
        
        7:
        
        cmpwi 0, r4, 0
        beqlr
        
        mtctr r4
        addi r6, r6, 3
        
        8:
        
        stbu r5, 1(r14)
        bdnz 8b
        
        blr

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