1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2020 Brandon Bergren <bdragon@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <machine/asm.h> 29 30/** 31 * int openfirmware_trampoline(void *buf, int (*cb)(void *)); 32 */ 33ASENTRY_NOPROF(openfirmware_trampoline) 34 mflr %r0 35 stw %r0, 4(%r1) 36 stwu %r1, -16(%r1) 37 stw %r30, 8(%r1) 38 /* Save current MSR for restoration post-call. */ 39 mfmsr %r30 40 mr %r5, %r30 41 /* Remove LE bit from MSR. */ 42 clrrwi %r5, %r5, 1 43 mtsrr0 %r4 44 mtsrr1 %r5 45 LOAD_LR_NIA 461: 47 mflr %r4 48 addi %r4, %r4, (2f - 1b) 49 mtlr %r4 50 /* Switch to BE and transfer control to OF entry */ 51 rfid 522: 53 /* Control is returned here, but in BE. */ 54 .long 0x05009f42 /* LOAD_LR_NIA */ 55 /* 0: */ 56 .long 0xa603db7f /* mtsrr1 %r30 */ 57 .long 0xa602c87f /* mflr %r30 */ 58 .long 0x1400de3b /* addi %r30, %r30, (1f - 0b) */ 59 .long 0xa603da7f /* mtsrr0 %r30 */ 60 .long 0x2400004c /* rfid */ 61 /* 1: */ 621: 63 /* Back to normal. Tidy up for return. */ 64 lwz %r30, 8(%r1) 65 lwz %r0, 20(%r1) 66 addi %r1, %r1, 16 67 mtlr %r0 68 blr 69ASEND(openfirmware_trampoline) 70