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 * $FreeBSD$ 28 */ 29 30#include <machine/asm.h> 31 32/** 33 * int openfirmware_trampoline(void *buf, int (*cb)(void *)); 34 */ 35ASENTRY_NOPROF(openfirmware_trampoline) 36 mflr %r0 37 stw %r0, 4(%r1) 38 stwu %r1, -16(%r1) 39 stw %r30, 8(%r1) 40 /* Save current MSR for restoration post-call. */ 41 mfmsr %r30 42 mr %r5, %r30 43 /* Remove LE bit from MSR. */ 44 clrrwi %r5, %r5, 1 45 mtsrr0 %r4 46 mtsrr1 %r5 47 LOAD_LR_NIA 481: 49 mflr %r4 50 addi %r4, %r4, (2f - 1b) 51 mtlr %r4 52 /* Switch to BE and transfer control to OF entry */ 53 rfid 542: 55 /* Control is returned here, but in BE. */ 56 .long 0x05009f42 /* LOAD_LR_NIA */ 57 /* 0: */ 58 .long 0xa603db7f /* mtsrr1 %r30 */ 59 .long 0xa602c87f /* mflr %r30 */ 60 .long 0x1400de3b /* addi %r30, %r30, (1f - 0b) */ 61 .long 0xa603da7f /* mtsrr0 %r30 */ 62 .long 0x2400004c /* rfid */ 63 /* 1: */ 641: 65 /* Back to normal. Tidy up for return. */ 66 lwz %r30, 8(%r1) 67 lwz %r0, 20(%r1) 68 addi %r1, %r1, 16 69 mtlr %r0 70 blr 71ASEND(openfirmware_trampoline) 72