1 files changed, 265 insertions, 0 deletions
diff --git a/arch/sparc/boot/piggyback.c b/arch/sparc/boot/piggyback.c
new file mode 100644
index 000000000..6d74064ad
--- /dev/null
+++ b/arch/sparc/boot/piggyback.c
@@ -0,0 +1,265 @@
+// 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;
+}