arch/sparc/boot/piggyback.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
    Simple utility to make a single-image install kernel with initial ramdisk
    for Sparc tftpbooting without need to set up nfs.

    Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
    Pete Zaitcev <zaitcev@yahoo.com> endian fixes for cross-compiles, 2000.
    Copyright (C) 2011 Sam Ravnborg <sam@ravnborg.org>

  */

 #include <dirent.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>

 #include <sys/types.h>
 #include <sys/stat.h>

 /*
  * Note: run this on an a.out kernel (use elftoaout for it),
  * as PROM looks for a.out image only.
  */

 #define AOUT_TEXT_OFFSET   32

 static int is64bit = 0;

 /* align to power-of-two size */
 static int align(int n)
 {
 	if (is64bit)
 		return (n + 0x1fff) & ~0x1fff;
 	else
 		return (n + 0xfff) & ~0xfff;
 }

 /* read two bytes as big endian */
 static unsigned short ld2(char *p)
 {
 	return (p[0] << 8) | p[1];
 }

 /* save 4 bytes as big endian */
 static void st4(char *p, unsigned int x)
 {
 	p[0] = x >> 24;
 	p[1] = x >> 16;
 	p[2] = x >> 8;
 	p[3] = x;
 }

 static void die(const char *str)
 {
 	perror(str);
 	exit(1);
 }

 static void usage(void)
 {
 	/* fs_img.gz is an image of initial ramdisk. */
 	fprintf(stderr, "Usage: piggyback bits vmlinux.aout System.map fs_img.gz\n");
 	fprintf(stderr, "\tKernel image will be modified in place.\n");
 	exit(1);
 }

 static int start_line(const char *line)
 {
 	if (strcmp(line + 10, " _start\n") == 0)
 		return 1;
 	else if (strcmp(line + 18, " _start\n") == 0)
 		return 1;
 	return 0;
 }

 static int end_line(const char *line)
 {
 	if (strcmp(line + 10, " _end\n") == 0)
 		return 1;
 	else if (strcmp (line + 18, " _end\n") == 0)
 		return 1;
 	return 0;
 }

 /*
  * Find address for start and end in System.map.
  * The file looks like this:
  * f0004000 ... _start
  * f0379f79 ... _end
  * 1234567890123456
  * ^coloumn 1
  * There is support for 64 bit addresses too.
  *
  * Return 0 if either start or end is not found
  */
 static int get_start_end(const char *filename, unsigned int *start,
                                                unsigned int *end)
 {
 	FILE *map;
 	char buffer[1024];

 	*start = 0;
 	*end = 0;
 	map = fopen(filename, "r");
 	if (!map)
 		die(filename);
 	while (fgets(buffer, 1024, map)) {
 		if (start_line(buffer))
 			*start = strtoul(buffer, NULL, 16);
 		else if (end_line(buffer))
 			*end = strtoul(buffer, NULL, 16);
 	}
 	fclose (map);

 	if (*start == 0 || *end == 0)
 		return 0;

 	return 1;
 }

 #define LOOKBACK (128 * 4)
 #define BUFSIZE 1024
 /*
  * Find the HdrS entry from head_32/head_64.
  * We check if it is at the beginning of the file (sparc64 case)
  * and if not we search for it.
  * When we search do so in steps of 4 as HdrS is on a 4-byte aligned
  * address (it is on same alignment as sparc instructions)
  * Return the offset to the HdrS entry (as off_t)
  */
 static off_t get_hdrs_offset(int kernelfd, const char *filename)
 {
 	char buffer[BUFSIZE];
 	off_t offset;
 	int i;

 	if (lseek(kernelfd, 0, SEEK_SET) < 0)
 		die("lseek");
 	if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE)
 		die(filename);

 	if (buffer[40] == 'H' && buffer[41] == 'd' &&
 	    buffer[42] == 'r' && buffer[43] == 'S') {
 		return 40;
 	} else {
 		/*  Find the gokernel label */
 		/* Decode offset from branch instruction */
 		offset = ld2(buffer + AOUT_TEXT_OFFSET + 2) << 2;
 		/* Go back 512 bytes so we do not miss HdrS */
 		offset -= LOOKBACK;
 		/* skip a.out header */
 		offset += AOUT_TEXT_OFFSET;
 		if (offset < 0) {
 			errno = -EINVAL;
 			die("Calculated a negative offset, probably elftoaout generated an invalid image. Did you use a recent elftoaout ?");
 		}
 		if (lseek(kernelfd, offset, SEEK_SET) < 0)
 			die("lseek");
 		if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE)
 			die(filename);

 		for (i = 0; i < LOOKBACK; i += 4) {
 			if (buffer[i + 0] == 'H' && buffer[i + 1] == 'd' &&
 			    buffer[i + 2] == 'r' && buffer[i + 3] == 'S') {
 				return offset + i;
 			}
 		}
 	}
 	fprintf (stderr, "Couldn't find headers signature in %s\n", filename);
 	exit(1);
 }

 int main(int argc,char **argv)
 {
 	static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 };
 	char buffer[1024];
 	unsigned int i, start, end;
 	off_t offset;
 	struct stat s;
 	int image, tail;

 	if (argc != 5)
 		usage();
 	if (strcmp(argv[1], "64") == 0)
 		is64bit = 1;
 	if (stat (argv[4], &s) < 0)
 		die(argv[4]);

 	if (!get_start_end(argv[3], &start, &end)) {
 		fprintf(stderr, "Could not determine start and end from %s\n",
 		        argv[3]);
 		exit(1);
 	}
 	if ((image = open(argv[2], O_RDWR)) < 0)
 		die(argv[2]);
 	if (read(image, buffer, 512) != 512)
 		die(argv[2]);
 	if (memcmp(buffer, aout_magic, 4) != 0) {
 		fprintf (stderr, "Not a.out. Don't blame me.\n");
 		exit(1);
 	}
 	/*
 	 * We need to fill in values for
 	 * sparc_ramdisk_image + sparc_ramdisk_size
 	 * To locate these symbols search for the "HdrS" text which appear
 	 * in the image a little before the gokernel symbol.
 	 * See definition of these in init_32.S
 	 */

 	offset = get_hdrs_offset(image, argv[2]);
 	/* skip HdrS + LINUX_VERSION_CODE + HdrS version */
 	offset += 10;

 	if (lseek(image, offset, 0) < 0)
 		die("lseek");

 	/*
 	 * root_flags = 0
 	 * root_dev = 1 (RAMDISK_MAJOR)
 	 * ram_flags = 0
 	 * sparc_ramdisk_image = "PAGE aligned address after _end")
 	 * sparc_ramdisk_size = size of image
 	 */
 	st4(buffer, 0);
 	st4(buffer + 4, 0x01000000);
 	st4(buffer + 8, align(end + 32));
 	st4(buffer + 12, s.st_size);

 	if (write(image, buffer + 2, 14) != 14)
 		die(argv[2]);

 	/* For sparc64 update a_text and clear a_data + a_bss */
 	if (is64bit)
 	{
 		if (lseek(image, 4, 0) < 0)
 			die("lseek");
 		/* a_text */
 		st4(buffer, align(end + 32 + 8191) - (start & ~0x3fffffUL) +
 		            s.st_size);
 		/* a_data */
 		st4(buffer + 4, 0);
 		/* a_bss */
 		st4(buffer + 8, 0);
 		if (write(image, buffer, 12) != 12)
 			die(argv[2]);
 	}

 	/* seek page aligned boundary in the image file and add boot image */
 	if (lseek(image, AOUT_TEXT_OFFSET - start + align(end + 32), 0) < 0)
 		die("lseek");
 	if ((tail = open(argv[4], O_RDONLY)) < 0)
 		die(argv[4]);
 	while ((i = read(tail, buffer, 1024)) > 0)
 		if (write(image, buffer, i) != i)
 			die(argv[2]);
 	if (close(image) < 0)
 		die("close");
 	if (close(tail) < 0)
 		die("close");
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	Simple utility to make a single-image install kernel with initial ramdisk
	for Sparc tftpbooting without need to set up nfs.

	Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	Pete Zaitcev <zaitcev@yahoo.com> endian fixes for cross-compiles, 2000.
	Copyright (C) 2011 Sam Ravnborg <sam@ravnborg.org>

	*/

	#include <dirent.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <ctype.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <stdio.h>

	#include <sys/types.h>
	#include <sys/stat.h>

	/*
	* Note: run this on an a.out kernel (use elftoaout for it),
	* as PROM looks for a.out image only.
	*/

	#define AOUT_TEXT_OFFSET 32

	static int is64bit = 0;

	/* align to power-of-two size */
	static int align(int n)
	{
	if (is64bit)
	return (n + 0x1fff) & ~0x1fff;
	else
	return (n + 0xfff) & ~0xfff;
	}

	/* read two bytes as big endian */
	static unsigned short ld2(char *p)
	{
	return (p[0] << 8) \| p[1];
	}

	/* save 4 bytes as big endian */
	static void st4(char *p, unsigned int x)
	{
	p[0] = x >> 24;
	p[1] = x >> 16;
	p[2] = x >> 8;
	p[3] = x;
	}

	static void die(const char *str)
	{
	perror(str);
	exit(1);
	}

	static void usage(void)
	{
	/* fs_img.gz is an image of initial ramdisk. */
	fprintf(stderr, "Usage: piggyback bits vmlinux.aout System.map fs_img.gz\n");
	fprintf(stderr, "\tKernel image will be modified in place.\n");
	exit(1);
	}

	static int start_line(const char *line)
	{
	if (strcmp(line + 10, " _start\n") == 0)
	return 1;
	else if (strcmp(line + 18, " _start\n") == 0)
	return 1;
	return 0;
	}

	static int end_line(const char *line)
	{
	if (strcmp(line + 10, " _end\n") == 0)
	return 1;
	else if (strcmp (line + 18, " _end\n") == 0)
	return 1;
	return 0;
	}

	/*
	* Find address for start and end in System.map.
	* The file looks like this:
	* f0004000 ... _start
	* f0379f79 ... _end
	* 1234567890123456
	* ^coloumn 1
	* There is support for 64 bit addresses too.
	*
	* Return 0 if either start or end is not found
	*/
	static int get_start_end(const char filename, unsigned int start,
	unsigned int *end)
	{
	FILE *map;
	char buffer[1024];

	*start = 0;
	*end = 0;
	map = fopen(filename, "r");
	if (!map)
	die(filename);
	while (fgets(buffer, 1024, map)) {
	if (start_line(buffer))
	*start = strtoul(buffer, NULL, 16);
	else if (end_line(buffer))
	*end = strtoul(buffer, NULL, 16);
	}
	fclose (map);

	if (start == 0 \|\| end == 0)
	return 0;

	return 1;
	}

	#define LOOKBACK (128 * 4)
	#define BUFSIZE 1024
	/*
	* Find the HdrS entry from head_32/head_64.
	* We check if it is at the beginning of the file (sparc64 case)
	* and if not we search for it.
	* When we search do so in steps of 4 as HdrS is on a 4-byte aligned
	* address (it is on same alignment as sparc instructions)
	* Return the offset to the HdrS entry (as off_t)
	*/
	static off_t get_hdrs_offset(int kernelfd, const char *filename)
	{
	char buffer[BUFSIZE];
	off_t offset;
	int i;

	if (lseek(kernelfd, 0, SEEK_SET) < 0)
	die("lseek");
	if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE)
	die(filename);

	if (buffer[40] == 'H' && buffer[41] == 'd' &&
	buffer[42] == 'r' && buffer[43] == 'S') {
	return 40;
	} else {
	/* Find the gokernel label */
	/* Decode offset from branch instruction */
	offset = ld2(buffer + AOUT_TEXT_OFFSET + 2) << 2;
	/* Go back 512 bytes so we do not miss HdrS */
	offset -= LOOKBACK;
	/* skip a.out header */
	offset += AOUT_TEXT_OFFSET;
	if (offset < 0) {
	errno = -EINVAL;
	die("Calculated a negative offset, probably elftoaout generated an invalid image. Did you use a recent elftoaout ?");
	}
	if (lseek(kernelfd, offset, SEEK_SET) < 0)
	die("lseek");
	if (read(kernelfd, buffer, BUFSIZE) != BUFSIZE)
	die(filename);

	for (i = 0; i < LOOKBACK; i += 4) {
	if (buffer[i + 0] == 'H' && buffer[i + 1] == 'd' &&
	buffer[i + 2] == 'r' && buffer[i + 3] == 'S') {
	return offset + i;
	}
	}
	}
	fprintf (stderr, "Couldn't find headers signature in %s\n", filename);
	exit(1);
	}

	int main(int argc,char **argv)
	{
	static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 };
	char buffer[1024];
	unsigned int i, start, end;
	off_t offset;
	struct stat s;
	int image, tail;

	if (argc != 5)
	usage();
	if (strcmp(argv[1], "64") == 0)
	is64bit = 1;
	if (stat (argv[4], &s) < 0)
	die(argv[4]);

	if (!get_start_end(argv[3], &start, &end)) {
	fprintf(stderr, "Could not determine start and end from %s\n",
	argv[3]);
	exit(1);
	}
	if ((image = open(argv[2], O_RDWR)) < 0)
	die(argv[2]);
	if (read(image, buffer, 512) != 512)
	die(argv[2]);
	if (memcmp(buffer, aout_magic, 4) != 0) {
	fprintf (stderr, "Not a.out. Don't blame me.\n");
	exit(1);
	}
	/*
	* We need to fill in values for
	* sparc_ramdisk_image + sparc_ramdisk_size
	* To locate these symbols search for the "HdrS" text which appear
	* in the image a little before the gokernel symbol.
	* See definition of these in init_32.S
	*/

	offset = get_hdrs_offset(image, argv[2]);
	/* skip HdrS + LINUX_VERSION_CODE + HdrS version */
	offset += 10;

	if (lseek(image, offset, 0) < 0)
	die("lseek");

	/*
	* root_flags = 0
	* root_dev = 1 (RAMDISK_MAJOR)
	* ram_flags = 0
	* sparc_ramdisk_image = "PAGE aligned address after _end")
	* sparc_ramdisk_size = size of image
	*/
	st4(buffer, 0);
	st4(buffer + 4, 0x01000000);
	st4(buffer + 8, align(end + 32));
	st4(buffer + 12, s.st_size);

	if (write(image, buffer + 2, 14) != 14)
	die(argv[2]);

	/* For sparc64 update a_text and clear a_data + a_bss */
	if (is64bit)
	{
	if (lseek(image, 4, 0) < 0)
	die("lseek");
	/* a_text */
	st4(buffer, align(end + 32 + 8191) - (start & ~0x3fffffUL) +
	s.st_size);
	/* a_data */
	st4(buffer + 4, 0);
	/* a_bss */
	st4(buffer + 8, 0);
	if (write(image, buffer, 12) != 12)
	die(argv[2]);
	}

	/* seek page aligned boundary in the image file and add boot image */
	if (lseek(image, AOUT_TEXT_OFFSET - start + align(end + 32), 0) < 0)
	die("lseek");
	if ((tail = open(argv[4], O_RDONLY)) < 0)
	die(argv[4]);
	while ((i = read(tail, buffer, 1024)) > 0)
	if (write(image, buffer, i) != i)
	die(argv[2]);
	if (close(image) < 0)
	die("close");
	if (close(tail) < 0)
	die("close");
	return 0;
	}