// SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause

  /*
   * Copyright 2013 Freescale Semiconductor, Inc.
   *

   * 64-bit and little-endian target only until we need to support a different
   * arch that needs this.
   */
  
  #include <elf.h>
  #include <errno.h>
  #include <inttypes.h>
  #include <stdarg.h>
  #include <stdbool.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>

  #include "compiler.h"

  
  #ifndef R_AARCH64_RELATIVE
  #define R_AARCH64_RELATIVE	1027
  #endif
  
  static const bool debug_en;
  
  static void debug(const char *fmt, ...)
  {
  	va_list args;

  	if (debug_en) {
  		va_start(args, fmt);

  		vprintf(fmt, args);

  		va_end(args);
  	}

  }
  
  static bool supported_rela(Elf64_Rela *rela)
  {
  	uint64_t mask = 0xffffffffULL; /* would be different on 32-bit */
  	uint32_t type = rela->r_info & mask;
  
  	switch (type) {
  #ifdef R_AARCH64_RELATIVE
  	case R_AARCH64_RELATIVE:
  		return true;
  #endif
  	default:
  		fprintf(stderr, "warning: unsupported relocation type %"
  				PRIu32 " at %" PRIx64 "
  ",
  			type, rela->r_offset);
  
  		return false;
  	}
  }

  static bool read_num(const char *str, uint64_t *num)
  {
  	char *endptr;
  	*num = strtoull(str, &endptr, 16);
  	return str[0] && !endptr[0];
  }
  
  int main(int argc, char **argv)
  {
  	FILE *f;
  	int i, num;
  	uint64_t rela_start, rela_end, text_base;
  
  	if (argc != 5) {
  		fprintf(stderr, "Statically apply ELF rela relocations
  ");
  		fprintf(stderr, "Usage: %s <bin file> <text base> " \
  				"<rela start> <rela end>
  ", argv[0]);
  		fprintf(stderr, "All numbers in hex.
  ");
  		return 1;
  	}
  
  	f = fopen(argv[1], "r+b");
  	if (!f) {
  		fprintf(stderr, "%s: Cannot open %s: %s
  ",
  			argv[0], argv[1], strerror(errno));
  		return 2;
  	}
  
  	if (!read_num(argv[2], &text_base) ||
  	    !read_num(argv[3], &rela_start) ||
  	    !read_num(argv[4], &rela_end)) {
  		fprintf(stderr, "%s: bad number
  ", argv[0]);
  		return 3;
  	}
  
  	if (rela_start > rela_end || rela_start < text_base ||

  	    (rela_end - rela_start) % sizeof(Elf64_Rela)) {

  		fprintf(stderr, "%s: bad rela bounds
  ", argv[0]);
  		return 3;
  	}
  
  	rela_start -= text_base;
  	rela_end -= text_base;
  
  	num = (rela_end - rela_start) / sizeof(Elf64_Rela);
  
  	for (i = 0; i < num; i++) {
  		Elf64_Rela rela, swrela;
  		uint64_t pos = rela_start + sizeof(Elf64_Rela) * i;
  		uint64_t addr;
  
  		if (fseek(f, pos, SEEK_SET) < 0) {
  			fprintf(stderr, "%s: %s: seek to %" PRIx64
  					" failed: %s
  ",
  				argv[0], argv[1], pos, strerror(errno));
  		}
  
  		if (fread(&rela, sizeof(rela), 1, f) != 1) {
  			fprintf(stderr, "%s: %s: read rela failed at %"
  					PRIx64 "
  ",
  				argv[0], argv[1], pos);
  			return 4;
  		}

  		swrela.r_offset = cpu_to_le64(rela.r_offset);
  		swrela.r_info = cpu_to_le64(rela.r_info);
  		swrela.r_addend = cpu_to_le64(rela.r_addend);

  
  		if (!supported_rela(&swrela))
  			continue;
  
  		debug("Rela %" PRIx64 " %" PRIu64 " %" PRIx64 "
  ",
  		      swrela.r_offset, swrela.r_info, swrela.r_addend);
  
  		if (swrela.r_offset < text_base) {
  			fprintf(stderr, "%s: %s: bad rela at %" PRIx64 "
  ",
  				argv[0], argv[1], pos);
  			return 4;
  		}
  
  		addr = swrela.r_offset - text_base;
  
  		if (fseek(f, addr, SEEK_SET) < 0) {
  			fprintf(stderr, "%s: %s: seek to %"
  					PRIx64 " failed: %s
  ",
  				argv[0], argv[1], addr, strerror(errno));
  		}
  
  		if (fwrite(&rela.r_addend, sizeof(rela.r_addend), 1, f) != 1) {
  			fprintf(stderr, "%s: %s: write failed at %" PRIx64 "
  ",
  				argv[0], argv[1], addr);
  			return 4;
  		}
  	}
  
  	if (fclose(f) < 0) {
  		fprintf(stderr, "%s: %s: close failed: %s
  ",
  			argv[0], argv[1], strerror(errno));
  		return 4;
  	}
  
  	return 0;
  }