70 lines
2.3 KiB
ArmAsm
70 lines
2.3 KiB
ArmAsm
/*-
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2020 Brandon Bergren <bdragon@FreeBSD.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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/**
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* int openfirmware_trampoline(void *buf, int (*cb)(void *));
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*/
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ASENTRY_NOPROF(openfirmware_trampoline)
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mflr %r0
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stw %r0, 4(%r1)
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stwu %r1, -16(%r1)
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stw %r30, 8(%r1)
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/* Save current MSR for restoration post-call. */
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mfmsr %r30
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mr %r5, %r30
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/* Remove LE bit from MSR. */
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clrrwi %r5, %r5, 1
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mtsrr0 %r4
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mtsrr1 %r5
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LOAD_LR_NIA
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1:
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mflr %r4
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addi %r4, %r4, (2f - 1b)
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mtlr %r4
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/* Switch to BE and transfer control to OF entry */
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rfid
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2:
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/* Control is returned here, but in BE. */
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.long 0x05009f42 /* LOAD_LR_NIA */
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/* 0: */
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.long 0xa603db7f /* mtsrr1 %r30 */
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.long 0xa602c87f /* mflr %r30 */
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.long 0x1400de3b /* addi %r30, %r30, (1f - 0b) */
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.long 0xa603da7f /* mtsrr0 %r30 */
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.long 0x2400004c /* rfid */
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/* 1: */
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1:
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/* Back to normal. Tidy up for return. */
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lwz %r30, 8(%r1)
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lwz %r0, 20(%r1)
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addi %r1, %r1, 16
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mtlr %r0
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blr
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ASEND(openfirmware_trampoline)
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