mksunxiboot.c

/*
 * modified by Liu Peiyuan
 * email: peiyuanix@gmail.com
 * date: 2023/10/14
 *
 * (C) Copyright 2007-2011
 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
 * Tom Cubie <tangliang@allwinnertech.com>
 *
 * a simple tool to generate bootable image for sunxi platform.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

typedef unsigned char u8;
typedef unsigned int u32;

/* boot head definition from sun4i boot code */
typedef struct __attribute__((packed)) boot_file_head
{
	u32  jump_instruction;   // one intruction jumping to real code
	u8   magic[8];           // ="eGON.BT0" or "eGON.BT1",  not C-style string.
	u32  check_sum;          // generated by PC
	u32  length;             // generated by PC
	u32  pub_head_size;      // the size of boot_file_head_t
	u8   pub_head_vsn[4];    // the version of boot_file_head_t
	u8   file_head_vsn[4];   // the version of boot0_file_head_t or boot1_file_head_t
	u8   Boot_vsn[4];        // Boot version
	u8   eGON_vsn[4];        // eGON version
	u8   platform[8];        // platform information
} boot_file_head_t;

#define BOOT0_MAGIC                     "eGON.BT0"
#define STAMP_VALUE                     0x5F0A6C39

#define ROUND_UP_TO_8(x) (((x) + 7) / 8 * 8)

/** encoding of the jump instruction to skip over the header */
#define BROM_FILE_HEAD_SIZE         (ROUND_UP_TO_8(sizeof(struct boot_file_head)) & 0x00FFFFF)  /* for some reasons, the entry point is aligned to 8 bytes */
#define BROM_FILE_HEAD_BIT_10_1     ((BROM_FILE_HEAD_SIZE & 0x7FE) >> 1)
#define BROM_FILE_HEAD_BIT_11       ((BROM_FILE_HEAD_SIZE & 0x800) >> 11)
#define BROM_FILE_HEAD_BIT_19_12    ((BROM_FILE_HEAD_SIZE & 0xFF000) >> 12)
#define BROM_FILE_HEAD_BIT_20       ((BROM_FILE_HEAD_SIZE & 0x100000) >> 20)
#define BROM_FILE_HEAD_SIZE_OFFSET \
    ((BROM_FILE_HEAD_BIT_20 << 31) | \
    (BROM_FILE_HEAD_BIT_10_1 << 21) | \
    (BROM_FILE_HEAD_BIT_11 << 20) | \
    (BROM_FILE_HEAD_BIT_19_12 << 12))
#define JUMP_INSTRUCTION        (BROM_FILE_HEAD_SIZE_OFFSET | 0x6f)

/* check sum functon from sun4i boot code */
int gen_check_sum( void *boot_buf )
{
	boot_file_head_t  *head_p;
	u32 length;
	u32 *buf;
	u32 loop;
	u32 i;
	u32 sum;

	head_p = (boot_file_head_t *)boot_buf;
	length = head_p->length;
	if( ( length & 0x3 ) != 0 )                   // must 4-byte-aligned
		return -1;
	buf = (u32 *)boot_buf;
	head_p->check_sum = STAMP_VALUE;              // fill stamp
	loop = length >> 2;
	/* calculate the sum */
	for( i = 0, sum = 0;  i < loop;  i++ )
		sum += buf[i];

	/* write back check sum */
	head_p->check_sum = sum;

	return 0;
}

#define ALIGN(x,a)      __ALIGN_MASK((x),(typeof(x))(a)-1)
#define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))

#define SUN4I_SRAM_SIZE (24 * 1024)
#define SRAM_LOAD_MAX_SIZE (SUN4I_SRAM_SIZE - sizeof(boot_file_head_t))
#define BLOCK_SIZE 512
struct __attribute__((packed)) boot_img {
	boot_file_head_t header;
	char code[SRAM_LOAD_MAX_SIZE];
	char pad[BLOCK_SIZE];
};

int main(int argc, char * argv[])
{
	int fd_in, fd_out;
	struct boot_img img;
	unsigned file_size, load_size;
	int count;

	if(argc < 2) {
		printf("\tThis program makes an input bin file to sun4i bootable image.\n"
				"\tUsage: %s input_file out_putfile\n", argv[0]);
		return EXIT_FAILURE;
	}

	fd_in = open(argv[1], O_RDONLY);
	if(fd_in < 0) {
		perror("Open input file:");
		return EXIT_FAILURE;
	}

	fd_out = open(argv[2], O_WRONLY|O_CREAT, 0666);
	if(fd_out < 0) {
		perror("Open output file:");
		return EXIT_FAILURE;
	}

	memset((void *)img.pad, 0, BLOCK_SIZE);

	/* get input file size */
	file_size = lseek(fd_in, 0, SEEK_END);
	printf("File size: 0x%x \n", file_size);

	if(file_size > SRAM_LOAD_MAX_SIZE) {
		load_size = SRAM_LOAD_MAX_SIZE;
	} else {
		load_size = ALIGN(file_size, sizeof(int));
	}
	printf("Load size: 0x%x \n", load_size);

	/* read file to buffer to calculate checksum */
	lseek(fd_in, 0, SEEK_SET);
	count = read(fd_in, img.code, load_size);
	printf("Read 0x%x bytes\n", count);

	/* fill the header */
	/* jump to the first instruction after the header */
	img.header.jump_instruction = JUMP_INSTRUCTION;
	memcpy(img.header.magic, BOOT0_MAGIC, 8);    /* no '0' termination */
	img.header.length = ALIGN(load_size + sizeof(boot_file_head_t), BLOCK_SIZE);
	img.header.pub_head_size = sizeof(boot_file_head_t);
	gen_check_sum((void *)&img);

	count = write(fd_out, (void *)&img, img.header.length);
	printf("Write 0x%x bytes\n", count);

	close(fd_in);
	close(fd_out);

	return EXIT_SUCCESS;
}