diff options
| -rw-r--r-- | arch/mips/Makefile.postlink | 23 | ||||
| -rw-r--r-- | arch/mips/config.mk | 21 | ||||
| -rw-r--r-- | arch/mips/cpu/start.S | 130 | ||||
| -rw-r--r-- | arch/mips/cpu/u-boot.lds | 41 | ||||
| -rw-r--r-- | arch/mips/include/asm/relocs.h | 24 | ||||
| -rw-r--r-- | arch/mips/include/asm/sections.h | 7 | ||||
| -rw-r--r-- | arch/mips/lib/Makefile | 1 | ||||
| -rw-r--r-- | arch/mips/lib/reloc.c | 164 | ||||
| -rw-r--r-- | common/board_f.c | 2 | ||||
| -rw-r--r-- | tools/.gitignore | 1 | ||||
| -rw-r--r-- | tools/Makefile | 2 | ||||
| -rw-r--r-- | tools/mips-relocs.c | 426 |
12 files changed, 663 insertions, 179 deletions
diff --git a/arch/mips/Makefile.postlink b/arch/mips/Makefile.postlink new file mode 100644 index 0000000000..7da3acdf52 --- /dev/null +++ b/arch/mips/Makefile.postlink @@ -0,0 +1,23 @@ +# +# Copyright (c) 2017 Imagination Technologies Ltd. +# +# SPDX-License-Identifier: GPL-2.0+ +# + +PHONY := __archpost +__archpost: + +-include include/config/auto.conf +include scripts/Kbuild.include + +CMD_RELOCS = tools/mips-relocs +quiet_cmd_relocs = RELOCS $@ + cmd_relocs = $(CMD_RELOCS) $@ + +u-boot: FORCE + @true + $(call if_changed,relocs) + +.PHONY: FORCE + +FORCE: diff --git a/arch/mips/config.mk b/arch/mips/config.mk index 2c72c1553d..cefdbe65e1 100644 --- a/arch/mips/config.mk +++ b/arch/mips/config.mk @@ -56,25 +56,14 @@ PLATFORM_ELFFLAGS += -B mips $(OBJCOPYFLAGS) # LDFLAGS_vmlinux += -G 0 -static -n -nostdlib # MODFLAGS += -mlong-calls # -# On the other hand, we want PIC in the U-Boot code to relocate it from ROM -# to RAM. $28 is always used as gp. -# -ifdef CONFIG_SPL_BUILD -PF_ABICALLS := -mno-abicalls -PF_PIC := -fno-pic -PF_PIE := -else -PF_ABICALLS := -mabicalls -PF_PIC := -fpic -PF_PIE := -pie -PF_OBJCOPY := -j .got -j .rel.dyn -j .padding -PF_OBJCOPY += -j .dtb.init.rodata +ifndef CONFIG_SPL_BUILD +OBJCOPYFLAGS += -j .got -j .rel -j .padding -j .dtb.init.rodata +LDFLAGS_FINAL += --emit-relocs endif -PLATFORM_CPPFLAGS += -G 0 $(PF_ABICALLS) $(PF_PIC) +PLATFORM_CPPFLAGS += -G 0 -mno-abicalls -fno-pic PLATFORM_CPPFLAGS += -msoft-float PLATFORM_LDFLAGS += -G 0 -static -n -nostdlib PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections -LDFLAGS_FINAL += --gc-sections $(PF_PIE) +LDFLAGS_FINAL += --gc-sections OBJCOPYFLAGS += -j .text -j .rodata -j .data -j .u_boot_list -OBJCOPYFLAGS += $(PF_OBJCOPY) diff --git a/arch/mips/cpu/start.S b/arch/mips/cpu/start.S index d01ee9f9bd..952c57afd7 100644 --- a/arch/mips/cpu/start.S +++ b/arch/mips/cpu/start.S @@ -221,18 +221,6 @@ wr_done: ehb #endif - /* - * Initialize $gp, force pointer sized alignment of bal instruction to - * forbid the compiler to put nop's between bal and _gp. This is - * required to keep _gp and ra aligned to 8 byte. - */ - .align PTRLOG - bal 1f - nop - PTR _gp -1: - PTR_L gp, 0(ra) - #ifdef CONFIG_MIPS_CM PTR_LA t9, mips_cm_map jalr t9 @@ -291,121 +279,3 @@ wr_done: move ra, zero END(_start) - -/* - * void relocate_code (addr_sp, gd, addr_moni) - * - * This "function" does not return, instead it continues in RAM - * after relocating the monitor code. - * - * a0 = addr_sp - * a1 = gd - * a2 = destination address - */ -ENTRY(relocate_code) - move sp, a0 # set new stack pointer - move fp, sp - - move s0, a1 # save gd in s0 - move s2, a2 # save destination address in s2 - - PTR_LI t0, CONFIG_SYS_MONITOR_BASE - PTR_SUB s1, s2, t0 # s1 <-- relocation offset - - PTR_LA t2, __image_copy_end - move t1, a2 - - /* - * t0 = source address - * t1 = target address - * t2 = source end address - */ -1: - PTR_L t3, 0(t0) - PTR_S t3, 0(t1) - PTR_ADDU t0, PTRSIZE - blt t0, t2, 1b - PTR_ADDU t1, PTRSIZE - - /* - * Now we want to update GOT. - * - * GOT[0] is reserved. GOT[1] is also reserved for the dynamic object - * generated by GNU ld. Skip these reserved entries from relocation. - */ - PTR_LA t3, num_got_entries - PTR_LA t8, _GLOBAL_OFFSET_TABLE_ - PTR_ADD t8, s1 # t8 now holds relocated _G_O_T_ - PTR_ADDIU t8, t8, 2 * PTRSIZE # skipping first two entries - PTR_LI t2, 2 -1: - PTR_L t1, 0(t8) - beqz t1, 2f - PTR_ADD t1, s1 - PTR_S t1, 0(t8) -2: - PTR_ADDIU t2, 1 - blt t2, t3, 1b - PTR_ADDIU t8, PTRSIZE - - /* Update dynamic relocations */ - PTR_LA t1, __rel_dyn_start - PTR_LA t2, __rel_dyn_end - - b 2f # skip first reserved entry - PTR_ADDIU t1, 2 * PTRSIZE - -1: - lw t8, -4(t1) # t8 <-- relocation info - - PTR_LI t3, MIPS_RELOC - bne t8, t3, 2f # skip non-MIPS_RELOC entries - nop - - PTR_L t3, -(2 * PTRSIZE)(t1) # t3 <-- location to fix up in FLASH - - PTR_L t8, 0(t3) # t8 <-- original pointer - PTR_ADD t8, s1 # t8 <-- adjusted pointer - - PTR_ADD t3, s1 # t3 <-- location to fix up in RAM - PTR_S t8, 0(t3) - -2: - blt t1, t2, 1b - PTR_ADDIU t1, 2 * PTRSIZE # each rel.dyn entry is 2*PTRSIZE bytes - - /* - * Flush caches to ensure our newly modified instructions are visible - * to the instruction cache. We're still running with the old GOT, so - * apply the reloc offset to the start address. - */ - PTR_LA a0, __text_start - PTR_LA a1, __text_end - PTR_SUB a1, a1, a0 - PTR_LA t9, flush_cache - jalr t9 - PTR_ADD a0, s1 - - PTR_ADD gp, s1 # adjust gp - - /* - * Clear BSS - * - * GOT is now relocated. Thus __bss_start and __bss_end can be - * accessed directly via $gp. - */ - PTR_LA t1, __bss_start # t1 <-- __bss_start - PTR_LA t2, __bss_end # t2 <-- __bss_end - -1: - PTR_S zero, 0(t1) - blt t1, t2, 1b - PTR_ADDIU t1, PTRSIZE - - move a0, s0 # a0 <-- gd - move a1, s2 - PTR_LA t9, board_init_r - jr t9 - move ra, zero - - END(relocate_code) diff --git a/arch/mips/cpu/u-boot.lds b/arch/mips/cpu/u-boot.lds index 0129c99611..bd5536f013 100644 --- a/arch/mips/cpu/u-boot.lds +++ b/arch/mips/cpu/u-boot.lds @@ -34,15 +34,6 @@ SECTIONS *(.data*) } - . = .; - _gp = ALIGN(16) + 0x7ff0; - - .got : { - *(.got) - } - - num_got_entries = SIZEOF(.got) >> PTR_COUNT_SHIFT; - . = ALIGN(4); .sdata : { *(.sdata*) @@ -57,33 +48,19 @@ SECTIONS __image_copy_end = .; __init_end = .; - .rel.dyn : { - __rel_dyn_start = .; - *(.rel.dyn) - __rel_dyn_end = .; - } - - .padding : { - /* - * Workaround for a binutils feature (or bug?). - * - * The GNU ld from binutils puts the dynamic relocation - * entries into the .rel.dyn section. Sometimes it - * allocates more dynamic relocation entries than it needs - * and the unused slots are set to R_MIPS_NONE entries. - * - * However the size of the .rel.dyn section in the ELF - * section header does not cover the unused entries, so - * objcopy removes those during stripping. - * - * Create a small section here to avoid that. - */ - LONG(0xFFFFFFFF) + /* + * .rel must come last so that the mips-relocs tool can shrink + * the section size & the PT_LOAD program header filesz. + */ + .rel : { + __rel_start = .; + BYTE(0x0) + . += (32 * 1024) - 1; } _end = .; - .bss __rel_dyn_start (OVERLAY) : { + .bss __rel_start (OVERLAY) : { __bss_start = .; *(.sbss.*) *(.bss.*) diff --git a/arch/mips/include/asm/relocs.h b/arch/mips/include/asm/relocs.h new file mode 100644 index 0000000000..92e9d04f7c --- /dev/null +++ b/arch/mips/include/asm/relocs.h @@ -0,0 +1,24 @@ +/* + * MIPS Relocations + * + * Copyright (c) 2017 Imagination Technologies Ltd. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __ASM_MIPS_RELOCS_H__ +#define __ASM_MIPS_RELOCS_H__ + +#define R_MIPS_NONE 0 +#define R_MIPS_32 2 +#define R_MIPS_26 4 +#define R_MIPS_HI16 5 +#define R_MIPS_LO16 6 +#define R_MIPS_PC16 10 +#define R_MIPS_64 18 +#define R_MIPS_HIGHER 28 +#define R_MIPS_HIGHEST 29 +#define R_MIPS_PC21_S2 60 +#define R_MIPS_PC26_S2 61 + +#endif /* __ASM_MIPS_RELOCS_H__ */ diff --git a/arch/mips/include/asm/sections.h b/arch/mips/include/asm/sections.h index fc4640a392..b9d217999e 100644 --- a/arch/mips/include/asm/sections.h +++ b/arch/mips/include/asm/sections.h @@ -8,4 +8,11 @@ #include <asm-generic/sections.h> +/** + * __rel_start: Relocation data generated by the mips-relocs tool + * + * See arch/mips/lib/reloc.c for details on the format & use of this data. + */ +extern uint8_t __rel_start[]; + #endif diff --git a/arch/mips/lib/Makefile b/arch/mips/lib/Makefile index 659c6ad187..ef557c6932 100644 --- a/arch/mips/lib/Makefile +++ b/arch/mips/lib/Makefile @@ -8,6 +8,7 @@ obj-y += cache.o obj-y += cache_init.o obj-y += genex.o +obj-y += reloc.o obj-y += stack.o obj-y += traps.o diff --git a/arch/mips/lib/reloc.c b/arch/mips/lib/reloc.c new file mode 100644 index 0000000000..d0c52c9674 --- /dev/null +++ b/arch/mips/lib/reloc.c @@ -0,0 +1,164 @@ +/* + * MIPS Relocation + * + * Copyright (c) 2017 Imagination Technologies Ltd. + * + * SPDX-License-Identifier: GPL-2.0+ + * + * Relocation data, found in the .rel section, is generated by the mips-relocs + * tool & contains a record of all locations in the U-Boot binary that need to + * be fixed up during relocation. + * + * The data is a sequence of unsigned integers, which are of somewhat arbitrary + * size. This is achieved by encoding integers as a sequence of bytes, each of + * which contains 7 bits of data with the most significant bit indicating + * whether any further bytes need to be read. The least significant bits of the + * integer are found in the first byte - ie. it somewhat resembles little + * endian. + * + * Each pair of two integers represents a relocation that must be applied. The + * first integer represents the type of relocation as a standard ELF relocation + * type (ie. R_MIPS_*). The second integer represents the offset at which to + * apply the relocation, relative to the previous relocation or for the first + * relocation the start of the relocated .text section. + * + * The end of the relocation data is indicated when type R_MIPS_NONE (0) is + * read, at which point no further integers should be read. That is, the + * terminating R_MIPS_NONE reloc includes no offset. + */ + +#include <common.h> +#include <asm/relocs.h> +#include <asm/sections.h> + +/** + * read_uint() - Read an unsigned integer from the buffer + * @buf: pointer to a pointer to the reloc buffer + * + * Read one whole unsigned integer from the relocation data pointed to by @buf, + * advancing @buf past the bytes encoding the integer. + * + * Returns: the integer read from @buf + */ +static unsigned long read_uint(uint8_t **buf) +{ + unsigned long val = 0; + unsigned int shift = 0; + uint8_t new; + + do { + new = *(*buf)++; + val |= (new & 0x7f) << shift; + shift += 7; + } while (new & 0x80); + + return val; +} + +/** + * apply_reloc() - Apply a single relocation + * @type: the type of reloc (R_MIPS_*) + * @addr: the address that the reloc should be applied to + * @off: the relocation offset, ie. number of bytes we're moving U-Boot by + * + * Apply a single relocation of type @type at @addr. This function is + * intentionally simple, and does the bare minimum needed to fixup the + * relocated U-Boot - in particular, it does not check for overflows. + */ +static void apply_reloc(unsigned int type, void *addr, long off) +{ + uint32_t u32; + + switch (type) { + case R_MIPS_26: + u32 = *(uint32_t *)addr; + u32 = (u32 & GENMASK(31, 26)) | + ((u32 + (off >> 2)) & GENMASK(25, 0)); + *(uint32_t *)addr = u32; + break; + + case R_MIPS_32: + *(uint32_t *)addr += off; + break; + + case R_MIPS_64: + *(uint64_t *)addr += off; + break; + + case R_MIPS_HI16: + *(uint32_t *)addr += off >> 16; + break; + + default: + panic("Unhandled reloc type %u\n", type); + } +} + +/** + * relocate_code() - Relocate U-Boot, generally from flash to DDR + * @start_addr_sp: new stack pointer + * @new_gd: pointer to relocated global data + * @relocaddr: the address to relocate to + * + * Relocate U-Boot from its current location (generally in flash) to a new one + * (generally in DDR). This function will copy the U-Boot binary & apply + * relocations as necessary, then jump to board_init_r in the new build of + * U-Boot. As such, this function does not return. + */ +void relocate_code(ulong start_addr_sp, gd_t *new_gd, ulong relocaddr) +{ + unsigned long addr, length, bss_len; + uint8_t *buf, *bss_start; + unsigned int type; + long off; + + /* + * Ensure that we're relocating by an offset which is a multiple of + * 64KiB, ie. doesn't change the least significant 16 bits of any + * addresses. This allows us to discard R_MIPS_LO16 relocs, saving + * space in the U-Boot binary & complexity in handling them. + */ + off = relocaddr - (unsigned long)__text_start; + if (off & 0xffff) + panic("Mis-aligned relocation\n"); + + /* Copy U-Boot to RAM */ + length = __image_copy_end - __text_start; + memcpy((void *)relocaddr, __text_start, length); + + /* Now apply relocations to the copy in RAM */ + buf = __rel_start; + addr = relocaddr; + while (true) { + type = read_uint(&buf); + if (type == R_MIPS_NONE) + break; + + addr += read_uint(&buf) << 2; + apply_reloc(type, (void *)addr, off); + } + + /* Ensure the icache is coherent */ + flush_cache(relocaddr, length); + + /* Clear the .bss section */ + bss_start = (uint8_t *)((unsigned long)__bss_start + off); + bss_len = (unsigned long)&__bss_end - (unsigned long)__bss_start; + memset(bss_start, 0, bss_len); + + /* Jump to the relocated U-Boot */ + asm volatile( + "move $29, %0\n" + " move $4, %1\n" + " move $5, %2\n" + " move $31, $0\n" + " jr %3" + : /* no outputs */ + : "r"(start_addr_sp), + "r"(new_gd), + "r"(relocaddr), + "r"((unsigned long)board_init_r + off)); + + /* Since we jumped to the new U-Boot above, we won't get here */ + unreachable(); +} diff --git a/common/board_f.c b/common/board_f.c index ffa84e3566..49c8bc89f3 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -418,7 +418,7 @@ static int reserve_uboot(void) */ gd->relocaddr -= gd->mon_len; gd->relocaddr &= ~(4096 - 1); -#ifdef CONFIG_E500 +#if defined(CONFIG_E500) || defined(CONFIG_MIPS) /* round down to next 64 kB limit so that IVPR stays aligned */ gd->relocaddr &= ~(65536 - 1); #endif diff --git a/tools/.gitignore b/tools/.gitignore index 6ec71f5c7f..ac0c979319 100644 --- a/tools/.gitignore +++ b/tools/.gitignore @@ -11,6 +11,7 @@ /img2srec /kwboot /dumpimage +/mips-relocs /mkenvimage /mkimage /mkexynosspl diff --git a/tools/Makefile b/tools/Makefile index 62a7921e43..0743677dc8 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -211,6 +211,8 @@ hostprogs-$(CONFIG_STATIC_RELA) += relocate-rela hostprogs-y += fdtgrep fdtgrep-objs += $(LIBFDT_OBJS) fdtgrep.o +hostprogs-$(CONFIG_MIPS) += mips-relocs + # We build some files with extra pedantic flags to try to minimize things # that won't build on some weird host compiler -- though there are lots of # exceptions for files that aren't complaint. diff --git a/tools/mips-relocs.c b/tools/mips-relocs.c new file mode 100644 index 0000000000..b690fa53c4 --- /dev/null +++ b/tools/mips-relocs.c @@ -0,0 +1,426 @@ +/* + * 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; +} |