xref: /openbmc/u-boot/tools/relocate-rela.c (revision 413ab5b0)
1 /*
2  * Copyright 2013 Freescale Semiconductor, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
5  *
6  * 64-bit and little-endian target only until we need to support a different
7  * arch that needs this.
8  */
9 
10 #include <elf.h>
11 #include <errno.h>
12 #include <inttypes.h>
13 #include <stdarg.h>
14 #include <stdbool.h>
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <string.h>
18 #include "compiler.h"
19 
20 #ifndef R_AARCH64_RELATIVE
21 #define R_AARCH64_RELATIVE	1027
22 #endif
23 
24 static const bool debug_en;
25 
26 static void debug(const char *fmt, ...)
27 {
28 	va_list args;
29 
30 	if (debug_en) {
31 		va_start(args, fmt);
32 		vprintf(fmt, args);
33 		va_end(args);
34 	}
35 }
36 
37 static bool supported_rela(Elf64_Rela *rela)
38 {
39 	uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */
40 	uint32_t type = rela->r_info & mask;
41 
42 	switch (type) {
43 #ifdef R_AARCH64_RELATIVE
44 	case R_AARCH64_RELATIVE:
45 		return true;
46 #endif
47 	default:
48 		fprintf(stderr, "warning: unsupported relocation type %"
49 				PRIu32 " at %" PRIx64 "\n",
50 			type, rela->r_offset);
51 
52 		return false;
53 	}
54 }
55 
56 static bool read_num(const char *str, uint64_t *num)
57 {
58 	char *endptr;
59 	*num = strtoull(str, &endptr, 16);
60 	return str[0] && !endptr[0];
61 }
62 
63 int main(int argc, char **argv)
64 {
65 	FILE *f;
66 	int i, num;
67 	uint64_t rela_start, rela_end, text_base;
68 
69 	if (argc != 5) {
70 		fprintf(stderr, "Statically apply ELF rela relocations\n");
71 		fprintf(stderr, "Usage: %s <bin file> <text base> " \
72 				"<rela start> <rela end>\n", argv[0]);
73 		fprintf(stderr, "All numbers in hex.\n");
74 		return 1;
75 	}
76 
77 	f = fopen(argv[1], "r+b");
78 	if (!f) {
79 		fprintf(stderr, "%s: Cannot open %s: %s\n",
80 			argv[0], argv[1], strerror(errno));
81 		return 2;
82 	}
83 
84 	if (!read_num(argv[2], &text_base) ||
85 	    !read_num(argv[3], &rela_start) ||
86 	    !read_num(argv[4], &rela_end)) {
87 		fprintf(stderr, "%s: bad number\n", argv[0]);
88 		return 3;
89 	}
90 
91 	if (rela_start > rela_end || rela_start < text_base ||
92 	    (rela_end - rela_start) % sizeof(Elf64_Rela)) {
93 		fprintf(stderr, "%s: bad rela bounds\n", argv[0]);
94 		return 3;
95 	}
96 
97 	rela_start -= text_base;
98 	rela_end -= text_base;
99 
100 	num = (rela_end - rela_start) / sizeof(Elf64_Rela);
101 
102 	for (i = 0; i < num; i++) {
103 		Elf64_Rela rela, swrela;
104 		uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
105 		uint64_t addr;
106 
107 		if (fseek(f, pos, SEEK_SET) < 0) {
108 			fprintf(stderr, "%s: %s: seek to %" PRIx64
109 					" failed: %s\n",
110 				argv[0], argv[1], pos, strerror(errno));
111 		}
112 
113 		if (fread(&rela, sizeof(rela), 1, f) != 1) {
114 			fprintf(stderr, "%s: %s: read rela failed at %"
115 					PRIx64 "\n",
116 				argv[0], argv[1], pos);
117 			return 4;
118 		}
119 
120 		swrela.r_offset = cpu_to_le64(rela.r_offset);
121 		swrela.r_info = cpu_to_le64(rela.r_info);
122 		swrela.r_addend = cpu_to_le64(rela.r_addend);
123 
124 		if (!supported_rela(&swrela))
125 			continue;
126 
127 		debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "\n",
128 		      swrela.r_offset, swrela.r_info, swrela.r_addend);
129 
130 		if (swrela.r_offset < text_base) {
131 			fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "\n",
132 				argv[0], argv[1], pos);
133 			return 4;
134 		}
135 
136 		addr = swrela.r_offset - text_base;
137 
138 		if (fseek(f, addr, SEEK_SET) < 0) {
139 			fprintf(stderr, "%s: %s: seek to %"
140 					PRIx64 " failed: %s\n",
141 				argv[0], argv[1], addr, strerror(errno));
142 		}
143 
144 		if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
145 			fprintf(stderr, "%s: %s: write failed at %" PRIx64 "\n",
146 				argv[0], argv[1], addr);
147 			return 4;
148 		}
149 	}
150 
151 	if (fclose(f) < 0) {
152 		fprintf(stderr, "%s: %s: close failed: %s\n",
153 			argv[0], argv[1], strerror(errno));
154 		return 4;
155 	}
156 
157 	return 0;
158 }
159