1/*- 2 * Copyright (c) 2008 Semihalf, Rafal Czubak 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#include <machine/armreg.h> 31 32/* 33 * Entry point to the loader that U-Boot passes control to. 34 */ 35 .text 36 .globl _start 37_start: 38 /* Hint where to look for the API signature */ 39 ldr ip, =uboot_address 40 str sp, [ip] 41 42 /* Save U-Boot's r8 and r9 */ 43 ldr ip, =saved_regs 44 str r8, [ip, #0] 45 str r9, [ip, #4] 46 47#ifdef _ARM_ARCH_6 48 mrc p15, 0, r2, c1, c0, 0 49 orr r2, r2, #(CPU_CONTROL_UNAL_ENABLE) 50 orr r2, r2, #(CPU_CONTROL_AFLT_ENABLE) 51 mcr p15, 0, r2, c1, c0, 0 52#endif 53 54 /* Start loader */ 55 b main 56 57/* 58 * syscall() 59 */ 60ENTRY(syscall) 61 /* Save caller's lr, r8 and r9 */ 62 ldr ip, =saved_regs 63 str r8, [ip, #8] 64 str r9, [ip, #12] 65 str lr, [ip, #16] 66 /* Restore U-Boot's r8 and r9 */ 67 ldr r8, [ip, #0] 68 ldr r9, [ip, #4] 69 /* Call into U-Boot */ 70 ldr lr, =return_from_syscall 71 ldr ip, =syscall_ptr 72 ldr pc, [ip] 73return_from_syscall: 74 /* Restore loader's r8, r9 and lr */ 75 ldr ip, =saved_regs 76 ldr lr, [ip, #16] 77 ldr r9, [ip, #12] 78 ldr r8, [ip, #8] 79 /* Return to caller */ 80 mov pc, lr 81 82/* 83 * Data section 84 */ 85 .data 86 .align 4 87 .globl syscall_ptr 88syscall_ptr: 89 .long 0 90 91 .globl uboot_address 92uboot_address: 93 .long 0 94 95saved_regs: 96 .long 0 /* U-Boot's r8 */ 97 .long 0 /* U-Boot's r9 */ 98 .long 0 /* Loader's r8 */ 99 .long 0 /* Loader's r9 */ 100 .long 0 /* Loader's lr */ 101