2 * MIPS Relocation Data Generator
4 * Copyright (c) 2017 Imagination Technologies Ltd.
6 * SPDX-License-Identifier: GPL-2.0+
21 #include <asm/relocs.h>
23 #define hdr_field(pfx, idx, field) ({ \
28 _val = pfx##hdr64[idx].field; \
29 _size = sizeof(pfx##hdr64[0].field); \
31 _val = pfx##hdr32[idx].field; \
32 _size = sizeof(pfx##hdr32[0].field); \
39 _val = is_be ? be16toh(_val) : le16toh(_val); \
42 _val = is_be ? be32toh(_val) : le32toh(_val); \
45 _val = is_be ? be64toh(_val) : le64toh(_val); \
52 #define set_hdr_field(pfx, idx, field, val) ({ \
57 _size = sizeof(pfx##hdr64[0].field); \
59 _size = sizeof(pfx##hdr32[0].field); \
66 _val = is_be ? htobe16(val) : htole16(val); \
69 _val = is_be ? htobe32(val) : htole32(val); \
72 _val = is_be ? htobe64(val) : htole64(val); \
75 /* We should never reach here */ \
82 pfx##hdr64[idx].field = _val; \
84 pfx##hdr32[idx].field = _val; \
87 #define ehdr_field(field) \
88 hdr_field(e, 0, field)
89 #define phdr_field(idx, field) \
90 hdr_field(p, idx, field)
91 #define shdr_field(idx, field) \
92 hdr_field(s, idx, field)
94 #define set_phdr_field(idx, field, val) \
95 set_hdr_field(p, idx, field, val)
96 #define set_shdr_field(idx, field, val) \
97 set_hdr_field(s, idx, field, val)
99 #define shstr(idx) (&shstrtab[idx])
108 size_t relocs_sz, relocs_idx;
110 static int add_reloc(unsigned int type, uint64_t off)
112 struct mips_reloc *new;
123 /* Skip these relocs */
130 if (relocs_idx == relocs_sz) {
131 new_sz = relocs_sz ? relocs_sz * 2 : 128;
132 new = realloc(relocs, new_sz * sizeof(*relocs));
134 fprintf(stderr, "Out of memory\n");
142 relocs[relocs_idx++] = (struct mips_reloc){
150 static int parse_mips32_rel(const void *_rel)
152 const Elf32_Rel *rel = _rel;
155 off = is_be ? be32toh(rel->r_offset) : le32toh(rel->r_offset);
158 type = is_be ? be32toh(rel->r_info) : le32toh(rel->r_info);
159 type = ELF32_R_TYPE(type);
161 return add_reloc(type, off);
164 static int parse_mips64_rela(const void *_rel)
166 const Elf64_Rela *rel = _rel;
169 off = is_be ? be64toh(rel->r_offset) : le64toh(rel->r_offset);
172 type = rel->r_info >> (64 - 8);
174 return add_reloc(type, off);
177 static void output_uint(uint8_t **buf, uint64_t val)
189 static int compare_relocs(const void *a, const void *b)
191 const struct mips_reloc *ra = a, *rb = b;
193 return ra->offset - rb->offset;
196 int main(int argc, char *argv[])
198 unsigned int i, j, i_rel_shdr, sh_type, sh_entsize, sh_entries;
199 size_t rel_size, rel_actual_size, load_sz;
200 const char *shstrtab, *sh_name, *rel_pfx;
201 int (*parse_fn)(const void *rel);
202 uint8_t *buf_start, *buf;
203 const Elf32_Ehdr *ehdr32;
204 const Elf64_Ehdr *ehdr64;
215 fd = open(argv[1], O_RDWR);
217 fprintf(stderr, "Unable to open input file %s\n", argv[1]);
222 err = fstat(fd, &st);
224 fprintf(stderr, "Unable to fstat() input file\n");
228 elf = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
229 if (elf == MAP_FAILED) {
230 fprintf(stderr, "Unable to mmap() input file\n");
238 if (memcmp(&ehdr32->e_ident[EI_MAG0], ELFMAG, SELFMAG)) {
239 fprintf(stderr, "Input file is not an ELF\n");
241 goto out_free_relocs;
244 if (ehdr32->e_ident[EI_VERSION] != EV_CURRENT) {
245 fprintf(stderr, "Unrecognised ELF version\n");
247 goto out_free_relocs;
250 switch (ehdr32->e_ident[EI_CLASS]) {
258 fprintf(stderr, "Unrecognised ELF class\n");
260 goto out_free_relocs;
263 switch (ehdr32->e_ident[EI_DATA]) {
271 fprintf(stderr, "Unrecognised ELF data encoding\n");
273 goto out_free_relocs;
276 if (ehdr_field(e_type) != ET_EXEC) {
277 fprintf(stderr, "Input ELF is not an executable\n");
278 printf("type 0x%lx\n", ehdr_field(e_type));
280 goto out_free_relocs;
283 if (ehdr_field(e_machine) != EM_MIPS) {
284 fprintf(stderr, "Input ELF does not target MIPS\n");
286 goto out_free_relocs;
289 phdr32 = elf + ehdr_field(e_phoff);
290 phdr64 = elf + ehdr_field(e_phoff);
291 shdr32 = elf + ehdr_field(e_shoff);
292 shdr64 = elf + ehdr_field(e_shoff);
293 shstrtab = elf + shdr_field(ehdr_field(e_shstrndx), sh_offset);
295 i_rel_shdr = UINT_MAX;
296 for (i = 0; i < ehdr_field(e_shnum); i++) {
297 sh_name = shstr(shdr_field(i, sh_name));
299 if (!strcmp(sh_name, ".rel")) {
304 if (!strcmp(sh_name, ".text")) {
305 text_base = shdr_field(i, sh_addr);
309 if (i_rel_shdr == UINT_MAX) {
310 fprintf(stderr, "Unable to find .rel section\n");
312 goto out_free_relocs;
315 fprintf(stderr, "Unable to find .text base address\n");
317 goto out_free_relocs;
320 rel_pfx = is_64 ? ".rela." : ".rel.";
322 for (i = 0; i < ehdr_field(e_shnum); i++) {
323 sh_type = shdr_field(i, sh_type);
324 if ((sh_type != SHT_REL) && (sh_type != SHT_RELA))
327 sh_name = shstr(shdr_field(i, sh_name));
328 if (strncmp(sh_name, rel_pfx, strlen(rel_pfx))) {
329 if (strcmp(sh_name, ".rel") && strcmp(sh_name, ".rel.dyn"))
330 fprintf(stderr, "WARNING: Unexpected reloc section name '%s'\n", sh_name);
335 * Skip reloc sections which either don't correspond to another
336 * section in the ELF, or whose corresponding section isn't
337 * loaded as part of the U-Boot binary (ie. doesn't have the
341 for (j = 0; j < ehdr_field(e_shnum); j++) {
342 if (strcmp(&sh_name[strlen(rel_pfx) - 1], shstr(shdr_field(j, sh_name))))
345 skip = !(shdr_field(j, sh_flags) & SHF_ALLOC);
351 sh_offset = shdr_field(i, sh_offset);
352 sh_entsize = shdr_field(i, sh_entsize);
353 sh_entries = shdr_field(i, sh_size) / sh_entsize;
355 if (sh_type == SHT_REL) {
357 fprintf(stderr, "REL-style reloc in MIPS64 ELF?\n");
359 goto out_free_relocs;
361 parse_fn = parse_mips32_rel;
365 parse_fn = parse_mips64_rela;
367 fprintf(stderr, "RELA-style reloc in MIPS32 ELF?\n");
369 goto out_free_relocs;
373 for (j = 0; j < sh_entries; j++) {
374 err = parse_fn(elf + sh_offset + (j * sh_entsize));
376 goto out_free_relocs;
380 /* Sort relocs in ascending order of offset */
381 qsort(relocs, relocs_idx, sizeof(*relocs), compare_relocs);
383 /* Make reloc offsets relative to their predecessor */
384 for (i = relocs_idx - 1; i > 0; i--)
385 relocs[i].offset -= relocs[i - 1].offset;
387 /* Write the relocations to the .rel section */
388 buf = buf_start = elf + shdr_field(i_rel_shdr, sh_offset);
389 for (i = 0; i < relocs_idx; i++) {
390 output_uint(&buf, relocs[i].type);
391 output_uint(&buf, relocs[i].offset >> 2);
394 /* Write a terminating R_MIPS_NONE (0) */
395 output_uint(&buf, R_MIPS_NONE);
397 /* Ensure the relocs didn't overflow the .rel section */
398 rel_size = shdr_field(i_rel_shdr, sh_size);
399 rel_actual_size = buf - buf_start;
400 if (rel_actual_size > rel_size) {
401 fprintf(stderr, "Relocs overflowed .rel section\n");
405 /* Update the .rel section's size */
406 set_shdr_field(i_rel_shdr, sh_size, rel_actual_size);
408 /* Shrink the PT_LOAD program header filesz (ie. shrink u-boot.bin) */
409 for (i = 0; i < ehdr_field(e_phnum); i++) {
410 if (phdr_field(i, p_type) != PT_LOAD)
413 load_sz = phdr_field(i, p_filesz);
414 load_sz -= rel_size - rel_actual_size;
415 set_phdr_field(i, p_filesz, load_sz);
419 /* Make sure data is written back to the file */
420 err = msync(elf, st.st_size, MS_SYNC);
422 fprintf(stderr, "Failed to msync: %d\n", errno);
423 goto out_free_relocs;
428 munmap(elf, st.st_size);