1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2020 Mitchell Horne <mhorne@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 * We need to be a PE32+ file for EFI. On some architectures we can use 32 * objcopy to create the correct file, however on RISC-V we need to do 33 * it ourselves. 34 */ 35 36#define IMAGE_FILE_MACHINE_RISCV64 0x5064 37 38#define IMAGE_SCN_CNT_CODE 0x00000020 39#define IMAGE_SCN_CNT_INITIALIZED_DATA 0x00000040 40#define IMAGE_SCN_MEM_DISCARDABLE 0x02000000 41#define IMAGE_SCN_MEM_EXECUTE 0x20000000 42#define IMAGE_SCN_MEM_READ 0x40000000 43 44 .section .peheader,"a" 45efi_start: 46 /* The MS-DOS Stub, only used to get the offset of the COFF header */ 47 .ascii "MZ" 48 .short 0 49 .space 0x38 50 .long pe_sig - efi_start 51 52 /* The PE32 Signature. Needs to be 8-byte aligned */ 53 .align 3 54pe_sig: 55 .ascii "PE" 56 .short 0 57coff_head: 58 .short IMAGE_FILE_MACHINE_RISCV64 /* RISC-V 64 file */ 59 .short 2 /* 2 Sections */ 60 .long 0 /* Timestamp */ 61 .long 0 /* No symbol table */ 62 .long 0 /* No symbols */ 63 .short section_table - optional_header /* Optional header size */ 64 .short 0 /* Characteristics TODO: Fill in */ 65 66optional_header: 67 .short 0x020b /* PE32+ (64-bit addressing) */ 68 .byte 0 /* Major linker version */ 69 .byte 0 /* Minor linker version */ 70 .long _edata - _end_header /* Code size */ 71 .long 0 /* No initialized data */ 72 .long 0 /* No uninitialized data */ 73 .long _start - efi_start /* Entry point */ 74 .long _end_header - efi_start /* Start of code */ 75 76optional_windows_header: 77 .quad 0 /* Image base */ 78 .long 32 /* Section Alignment */ 79 .long 8 /* File alignment */ 80 .short 0 /* Major OS version */ 81 .short 0 /* Minor OS version */ 82 .short 0 /* Major image version */ 83 .short 0 /* Minor image version */ 84 .short 0 /* Major subsystem version */ 85 .short 0 /* Minor subsystem version */ 86 .long 0 /* Win32 version */ 87 .long _edata - efi_start /* Image size */ 88 .long _end_header - efi_start /* Header size */ 89 .long 0 /* Checksum */ 90 .short 0xa /* Subsystem (EFI app) */ 91 .short 0 /* DLL Characteristics */ 92 .quad 0 /* Stack reserve */ 93 .quad 0 /* Stack commit */ 94 .quad 0 /* Heap reserve */ 95 .quad 0 /* Heap commit */ 96 .long 0 /* Loader flags */ 97 .long 6 /* Number of RVAs */ 98 99 /* RVAs: */ 100 .quad 0 101 .quad 0 102 .quad 0 103 .quad 0 104 .quad 0 105 .quad 0 106 107section_table: 108 /* We need a .reloc section for EFI */ 109 .ascii ".reloc" 110 .byte 0 111 .byte 0 /* Pad to 8 bytes */ 112 .long 0 /* Virtual size */ 113 .long 0 /* Virtual address */ 114 .long 0 /* Size of raw data */ 115 .long 0 /* Pointer to raw data */ 116 .long 0 /* Pointer to relocations */ 117 .long 0 /* Pointer to line numbers */ 118 .short 0 /* Number of relocations */ 119 .short 0 /* Number of line numbers */ 120 .long (IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | \ 121 IMAGE_SCN_MEM_DISCARDABLE) /* Characteristics */ 122 123 /* The contents of the loader */ 124 .ascii ".text" 125 .byte 0 126 .byte 0 127 .byte 0 /* Pad to 8 bytes */ 128 .long _edata - _end_header /* Virtual size */ 129 .long _end_header - efi_start /* Virtual address */ 130 .long _edata - _end_header /* Size of raw data */ 131 .long _end_header - efi_start /* Pointer to raw data */ 132 .long 0 /* Pointer to relocations */ 133 .long 0 /* Pointer to line numbers */ 134 .short 0 /* Number of relocations */ 135 .short 0 /* Number of line numbers */ 136 .long (IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | \ 137 IMAGE_SCN_MEM_READ) /* Characteristics */ 138_end_header: 139 140 .text 141 .globl _start 142_start: 143 /* Save the boot params to the stack */ 144 addi sp, sp, -16 145 sd a0, 0(sp) 146 sd a1, 8(sp) 147 148 /* Zero the BSS */ 149 lla t0, __bss_start 150 lla t1, __bss_end 151 1521: sd zero, 0(t0) 153 addi t0, t0, 8 154 bltu t0, t1, 1b 155 156 lla a0, ImageBase 157 lla a1, _DYNAMIC 158 call _C_LABEL(self_reloc) 159 160 ld a1, 8(sp) 161 ld a0, 0(sp) 162 tail _C_LABEL(efi_main) 163 164 /* NOTREACHED */ 1652: wfi 166 j 2b 167