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 27#include <machine/asm.h> 28 29/* 30 * Entry point to the loader that U-Boot passes control to. 31 */ 32 .text 33 .globl _start 34_start: 35 /* Hint where to look for the API signature */ 36 lis %r11, uboot_address@ha 37 addi %r11, %r11, uboot_address@l 38 stw %r1, 0(%r11) 39 /* Save U-Boot's r14 and r30 */ 40 lis %r11, saved_regs@ha 41 addi %r11, %r11, saved_regs@l 42 stw %r14, 0(%r11) 43 stw %r30, 4(%r11) 44 /* Disable interrupts */ 45 mfmsr %r11 46 andi. %r11, %r11, ~0x8000@l 47 mtmsr %r11 48 b main 49 50/* 51 * syscall() 52 */ 53ENTRY(syscall) 54 stwu %r1, -32(%r1) 55 mflr %r0 56 stw %r14, 8(%r1) 57 stw %r30, 12(%r1) 58 stw %r0, 36(%r1) 59 /* Restore U-Boot's r14 and r30 */ 60 lis %r11, saved_regs@ha 61 addi %r11, %r11, saved_regs@l 62 lwz %r14, 0(%r11) 63 lwz %r30, 4(%r11) 64 /* Enable interrupts */ 65 mfmsr %r11 66 ori %r11, %r11, 0x8000@l 67 mtmsr %r11 68 /* Call into U-Boot */ 69 lis %r11, syscall_ptr@ha 70 addi %r11, %r11, syscall_ptr@l 71 lwz %r11, 0(%r11) 72 mtctr %r11 73 bctrl 74 /* Disable interrupts */ 75 mfmsr %r11 76 andi. %r11, %r11, ~0x8000@l 77 mtmsr %r11 78 /* Epilogue */ 79 lwz %r11, 0(%r1) 80 lwz %r0, 4(%r11) 81 mtlr %r0 82 lwz %r14, 8(%r1) 83 lwz %r30, 12(%r1) 84 mr %r1, %r11 85 blr 86END(syscall) 87 88/* 89 * Data section 90 */ 91 .data 92GLOBAL(syscall_ptr) 93 .long 0 94GLOBAL(saved_regs) 95 .long 0 /* R14 */ 96 .long 0 /* R30 */ 97GLOBAL(uboot_address) 98 .long 0 99