--- /dev/null
+/*
+ * MIPS Relocation Data Generator
+ *
+ * Copyright (c) 2017 Imagination Technologies Ltd.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <asm/relocs.h>
+
+#define hdr_field(pfx, idx, field) ({ \
+ uint64_t _val; \
+ unsigned int _size; \
+ \
+ if (is_64) { \
+ _val = pfx##hdr64[idx].field; \
+ _size = sizeof(pfx##hdr64[0].field); \
+ } else { \
+ _val = pfx##hdr32[idx].field; \
+ _size = sizeof(pfx##hdr32[0].field); \
+ } \
+ \
+ switch (_size) { \
+ case 1: \
+ break; \
+ case 2: \
+ _val = is_be ? be16toh(_val) : le16toh(_val); \
+ break; \
+ case 4: \
+ _val = is_be ? be32toh(_val) : le32toh(_val); \
+ break; \
+ case 8: \
+ _val = is_be ? be64toh(_val) : le64toh(_val); \
+ break; \
+ } \
+ \
+ _val; \
+})
+
+#define set_hdr_field(pfx, idx, field, val) ({ \
+ uint64_t _val; \
+ unsigned int _size; \
+ \
+ if (is_64) \
+ _size = sizeof(pfx##hdr64[0].field); \
+ else \
+ _size = sizeof(pfx##hdr32[0].field); \
+ \
+ switch (_size) { \
+ case 1: \
+ _val = val; \
+ break; \
+ case 2: \
+ _val = is_be ? htobe16(val) : htole16(val); \
+ break; \
+ case 4: \
+ _val = is_be ? htobe32(val) : htole32(val); \
+ break; \
+ case 8: \
+ _val = is_be ? htobe64(val) : htole64(val); \
+ break; \
+ } \
+ \
+ if (is_64) \
+ pfx##hdr64[idx].field = _val; \
+ else \
+ pfx##hdr32[idx].field = _val; \
+})
+
+#define ehdr_field(field) \
+ hdr_field(e, 0, field)
+#define phdr_field(idx, field) \
+ hdr_field(p, idx, field)
+#define shdr_field(idx, field) \
+ hdr_field(s, idx, field)
+
+#define set_phdr_field(idx, field, val) \
+ set_hdr_field(p, idx, field, val)
+#define set_shdr_field(idx, field, val) \
+ set_hdr_field(s, idx, field, val)
+
+#define shstr(idx) (&shstrtab[idx])
+
+bool is_64, is_be;
+uint64_t text_base;
+
+struct mips_reloc {
+ uint8_t type;
+ uint64_t offset;
+} *relocs;
+size_t relocs_sz, relocs_idx;
+
+static int add_reloc(unsigned int type, uint64_t off)
+{
+ struct mips_reloc *new;
+ size_t new_sz;
+
+ switch (type) {
+ case R_MIPS_NONE:
+ case R_MIPS_LO16:
+ case R_MIPS_PC16:
+ case R_MIPS_HIGHER:
+ case R_MIPS_HIGHEST:
+ case R_MIPS_PC21_S2:
+ case R_MIPS_PC26_S2:
+ /* Skip these relocs */
+ return 0;
+
+ default:
+ break;
+ }
+
+ if (relocs_idx == relocs_sz) {
+ new_sz = relocs_sz ? relocs_sz * 2 : 128;
+ new = realloc(relocs, new_sz * sizeof(*relocs));
+ if (!new) {
+ fprintf(stderr, "Out of memory\n");
+ return -ENOMEM;
+ }
+
+ relocs = new;
+ relocs_sz = new_sz;
+ }
+
+ relocs[relocs_idx++] = (struct mips_reloc){
+ .type = type,
+ .offset = off,
+ };
+
+ return 0;
+}
+
+static int parse_mips32_rel(const void *_rel)
+{
+ const Elf32_Rel *rel = _rel;
+ uint32_t off, type;
+
+ off = is_be ? be32toh(rel->r_offset) : le32toh(rel->r_offset);
+ off -= text_base;
+
+ type = is_be ? be32toh(rel->r_info) : le32toh(rel->r_info);
+ type = ELF32_R_TYPE(type);
+
+ return add_reloc(type, off);
+}
+
+static int parse_mips64_rela(const void *_rel)
+{
+ const Elf64_Rela *rel = _rel;
+ uint64_t off, type;
+
+ off = is_be ? be64toh(rel->r_offset) : le64toh(rel->r_offset);
+ off -= text_base;
+
+ type = rel->r_info >> (64 - 8);
+
+ return add_reloc(type, off);
+}
+
+static void output_uint(uint8_t **buf, uint64_t val)
+{
+ uint64_t tmp;
+
+ do {
+ tmp = val & 0x7f;
+ val >>= 7;
+ tmp |= !!val << 7;
+ *(*buf)++ = tmp;
+ } while (val);
+}
+
+static int compare_relocs(const void *a, const void *b)
+{
+ const struct mips_reloc *ra = a, *rb = b;
+
+ return ra->offset - rb->offset;
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int i, j, i_rel_shdr, sh_type, sh_entsize, sh_entries;
+ size_t rel_size, rel_actual_size, load_sz;
+ const char *shstrtab, *sh_name, *rel_pfx;
+ int (*parse_fn)(const void *rel);
+ uint8_t *buf_start, *buf;
+ const Elf32_Ehdr *ehdr32;
+ const Elf64_Ehdr *ehdr64;
+ uintptr_t sh_offset;
+ Elf32_Phdr *phdr32;
+ Elf64_Phdr *phdr64;
+ Elf32_Shdr *shdr32;
+ Elf64_Shdr *shdr64;
+ struct stat st;
+ int err, fd;
+ void *elf;
+ bool skip;
+
+ fd = open(argv[1], O_RDWR);
+ if (fd == -1) {
+ fprintf(stderr, "Unable to open input file %s\n", argv[1]);
+ err = errno;
+ goto out_ret;
+ }
+
+ err = fstat(fd, &st);
+ if (err) {
+ fprintf(stderr, "Unable to fstat() input file\n");
+ goto out_close_fd;
+ }
+
+ elf = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (elf == MAP_FAILED) {
+ fprintf(stderr, "Unable to mmap() input file\n");
+ err = errno;
+ goto out_close_fd;
+ }
+
+ ehdr32 = elf;
+ ehdr64 = elf;
+
+ if (memcmp(&ehdr32->e_ident[EI_MAG0], ELFMAG, SELFMAG)) {
+ fprintf(stderr, "Input file is not an ELF\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ if (ehdr32->e_ident[EI_VERSION] != EV_CURRENT) {
+ fprintf(stderr, "Unrecognised ELF version\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ switch (ehdr32->e_ident[EI_CLASS]) {
+ case ELFCLASS32:
+ is_64 = false;
+ break;
+ case ELFCLASS64:
+ is_64 = true;
+ break;
+ default:
+ fprintf(stderr, "Unrecognised ELF class\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ switch (ehdr32->e_ident[EI_DATA]) {
+ case ELFDATA2LSB:
+ is_be = false;
+ break;
+ case ELFDATA2MSB:
+ is_be = true;
+ break;
+ default:
+ fprintf(stderr, "Unrecognised ELF data encoding\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ if (ehdr_field(e_type) != ET_EXEC) {
+ fprintf(stderr, "Input ELF is not an executable\n");
+ printf("type 0x%lx\n", ehdr_field(e_type));
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ if (ehdr_field(e_machine) != EM_MIPS) {
+ fprintf(stderr, "Input ELF does not target MIPS\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ phdr32 = elf + ehdr_field(e_phoff);
+ phdr64 = elf + ehdr_field(e_phoff);
+ shdr32 = elf + ehdr_field(e_shoff);
+ shdr64 = elf + ehdr_field(e_shoff);
+ shstrtab = elf + shdr_field(ehdr_field(e_shstrndx), sh_offset);
+
+ i_rel_shdr = UINT_MAX;
+ for (i = 0; i < ehdr_field(e_shnum); i++) {
+ sh_name = shstr(shdr_field(i, sh_name));
+
+ if (!strcmp(sh_name, ".rel")) {
+ i_rel_shdr = i;
+ continue;
+ }
+
+ if (!strcmp(sh_name, ".text")) {
+ text_base = shdr_field(i, sh_addr);
+ continue;
+ }
+ }
+ if (i_rel_shdr == UINT_MAX) {
+ fprintf(stderr, "Unable to find .rel section\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+ if (!text_base) {
+ fprintf(stderr, "Unable to find .text base address\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+
+ rel_pfx = is_64 ? ".rela." : ".rel.";
+
+ for (i = 0; i < ehdr_field(e_shnum); i++) {
+ sh_type = shdr_field(i, sh_type);
+ if ((sh_type != SHT_REL) && (sh_type != SHT_RELA))
+ continue;
+
+ sh_name = shstr(shdr_field(i, sh_name));
+ if (strncmp(sh_name, rel_pfx, strlen(rel_pfx))) {
+ if (strcmp(sh_name, ".rel") && strcmp(sh_name, ".rel.dyn"))
+ fprintf(stderr, "WARNING: Unexpected reloc section name '%s'\n", sh_name);
+ continue;
+ }
+
+ /*
+ * Skip reloc sections which either don't correspond to another
+ * section in the ELF, or whose corresponding section isn't
+ * loaded as part of the U-Boot binary (ie. doesn't have the
+ * alloc flags set).
+ */
+ skip = true;
+ for (j = 0; j < ehdr_field(e_shnum); j++) {
+ if (strcmp(&sh_name[strlen(rel_pfx) - 1], shstr(shdr_field(j, sh_name))))
+ continue;
+
+ skip = !(shdr_field(j, sh_flags) & SHF_ALLOC);
+ break;
+ }
+ if (skip)
+ continue;
+
+ sh_offset = shdr_field(i, sh_offset);
+ sh_entsize = shdr_field(i, sh_entsize);
+ sh_entries = shdr_field(i, sh_size) / sh_entsize;
+
+ if (sh_type == SHT_REL) {
+ if (is_64) {
+ fprintf(stderr, "REL-style reloc in MIPS64 ELF?\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ } else {
+ parse_fn = parse_mips32_rel;
+ }
+ } else {
+ if (is_64) {
+ parse_fn = parse_mips64_rela;
+ } else {
+ fprintf(stderr, "RELA-style reloc in MIPS32 ELF?\n");
+ err = -EINVAL;
+ goto out_free_relocs;
+ }
+ }
+
+ for (j = 0; j < sh_entries; j++) {
+ err = parse_fn(elf + sh_offset + (j * sh_entsize));
+ if (err)
+ goto out_free_relocs;
+ }
+ }
+
+ /* Sort relocs in ascending order of offset */
+ qsort(relocs, relocs_idx, sizeof(*relocs), compare_relocs);
+
+ /* Make reloc offsets relative to their predecessor */
+ for (i = relocs_idx - 1; i > 0; i--)
+ relocs[i].offset -= relocs[i - 1].offset;
+
+ /* Write the relocations to the .rel section */
+ buf = buf_start = elf + shdr_field(i_rel_shdr, sh_offset);
+ for (i = 0; i < relocs_idx; i++) {
+ output_uint(&buf, relocs[i].type);
+ output_uint(&buf, relocs[i].offset >> 2);
+ }
+
+ /* Write a terminating R_MIPS_NONE (0) */
+ output_uint(&buf, R_MIPS_NONE);
+
+ /* Ensure the relocs didn't overflow the .rel section */
+ rel_size = shdr_field(i_rel_shdr, sh_size);
+ rel_actual_size = buf - buf_start;
+ if (rel_actual_size > rel_size) {
+ fprintf(stderr, "Relocs overflowed .rel section\n");
+ return -ENOMEM;
+ }
+
+ /* Update the .rel section's size */
+ set_shdr_field(i_rel_shdr, sh_size, rel_actual_size);
+
+ /* Shrink the PT_LOAD program header filesz (ie. shrink u-boot.bin) */
+ for (i = 0; i < ehdr_field(e_phnum); i++) {
+ if (phdr_field(i, p_type) != PT_LOAD)
+ continue;
+
+ load_sz = phdr_field(i, p_filesz);
+ load_sz -= rel_size - rel_actual_size;
+ set_phdr_field(i, p_filesz, load_sz);
+ break;
+ }
+
+ /* Make sure data is written back to the file */
+ err = msync(elf, st.st_size, MS_SYNC);
+ if (err) {
+ fprintf(stderr, "Failed to msync: %d\n", errno);
+ goto out_free_relocs;
+ }
+
+out_free_relocs:
+ free(relocs);
+ munmap(elf, st.st_size);
+out_close_fd:
+ close(fd);
+out_ret:
+ return err;
+}
projects / u-boot / blobdiff