1/*- 2 * Copyright (c) 2007 Semihalf, Rafal Jaworowski <raj@semihalf.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#include <machine/asm.h> 30 31/* 32 * Entry point to the loader that U-Boot passes control to. 33 */ 34 .text 35 .globl _start 36_start: 37 /* Hint where to look for the API signature */ 38 lis %r11, uboot_address@ha 39 addi %r11, %r11, uboot_address@l 40 stw %r1, 0(%r11) 41 /* Save U-Boot's r14 and r30 */ 42 lis %r11, saved_regs@ha 43 addi %r11, %r11, saved_regs@l 44 stw %r14, 0(%r11) 45 stw %r30, 4(%r11) 46 /* Disable interrupts */ 47 mfmsr %r11 48 andi. %r11, %r11, ~0x8000@l 49 mtmsr %r11 50 b main 51 52/* 53 * syscall() 54 */ 55ENTRY(syscall) 56 stwu %r1, -32(%r1) 57 mflr %r0 58 stw %r14, 8(%r1) 59 stw %r30, 12(%r1) 60 stw %r0, 36(%r1) 61 /* Restore U-Boot's r14 and r30 */ 62 lis %r11, saved_regs@ha 63 addi %r11, %r11, saved_regs@l 64 lwz %r14, 0(%r11) 65 lwz %r30, 4(%r11) 66 /* Enable interrupts */ 67 mfmsr %r11 68 ori %r11, %r11, 0x8000@l 69 mtmsr %r11 70 /* Call into U-Boot */ 71 lis %r11, syscall_ptr@ha 72 addi %r11, %r11, syscall_ptr@l 73 lwz %r11, 0(%r11) 74 mtctr %r11 75 bctrl 76 /* Disable interrupts */ 77 mfmsr %r11 78 andi. %r11, %r11, ~0x8000@l 79 mtmsr %r11 80 /* Epilogue */ 81 lwz %r11, 0(%r1) 82 lwz %r0, 4(%r11) 83 mtlr %r0 84 lwz %r14, 8(%r1) 85 lwz %r30, 12(%r1) 86 mr %r1, %r11 87 blr 88END(syscall) 89 90/* 91 * Data section 92 */ 93 .data 94GLOBAL(syscall_ptr) 95 .long 0 96GLOBAL(saved_regs) 97 .long 0 /* R14 */ 98 .long 0 /* R30 */ 99GLOBAL(uboot_address) 100 .long 0 101