Syslinux - Apr 2007 - boot 32 or 64 kernel depending on cpu

Hello,

The attached l32or64.c implements a com32 module that boots two
different kernels with different initrds depending on whether the cpu
has long mode support or not.

I stumbled upon two problems while developing it with current git
version (last commit 595705ffad4f63cfeb84e9bb1243df03808c2fff).

The first was that syslinux_boot_linux didn't work for me. Both the
command line and initrd data was garbage. The code I was developing is
attached as l32or64_linux.c

The seconda was that com32/include/syslinux/boot.h declares
syslinux_run_kernel_image, but it isn't defined anywhere, so I went with
syslinux_run_command.

Regards,
Luciano Rocha

PS: not gpg-signed because syslinux at zytor.com thinks that's suspicious.

-- 
lfr
0/0
-------------- next part --------------
/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2007 Luciano Rocha - All Rights Reserved
 *
 *   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, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * l32or64.c
 *
 * Load linux kernel depending on cpu support for long mode (64 bits)
 */

#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <console.h>
#include <cpuid.h>
#include <syslinux/boot.h>


int main(int argc, char *argv[])
{
	const char *kernel, *initrd;
	char cmdline[1024];
	int i;
	unsigned p;

	s_cpu cpu;

	openconsole(&dev_stdcon_r, &dev_stdcon_w);

	if (argc < 5) {
		fprintf(stderr, "missing options, usage:\n"
				"  l23or64 <32b kernel> <32b initrd> \\"
				"          <64b kernel> <64b initrd> \\"
				"          [kernel arguments]\n");
		return 1;
	}

	detect_cpu(&cpu);

	if (cpu.flags.lm) {
		initrd = argv[4];
		kernel = argv[3];
	} else {
		initrd = argv[2];
		kernel = argv[1];
	}

	p = snprintf(cmdline, sizeof cmdline - 1, "%s initrd=%s ",
			kernel, initrd);
	for (i = 5; i < argc; i++) {
		unsigned l = strlen(argv[i]);
		if ((p + l + 1) >= sizeof cmdline) {
			fprintf(stderr, "command line exceeds internal "
					"buffers, trimmed.\n");
			break;
		}
		memcpy(cmdline + p, argv[i], l);
		cmdline[p + l] = ' ';
		p += l + 1;
	}
	cmdline[p] = '\0';

	syslinux_run_command(cmdline);

	return 1;
}
-------------- next part --------------
/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2007 Luciano Rocha - All Rights Reserved
 *
 *   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, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * l32or64.c
 *
 * Load linux kernel depending on cpu support for long mode (64 bits)
 */

#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <console.h>
#include <syslinux/loadfile.h>
#include <syslinux/linux.h>
#include "cpuid.h"


int main(int argc, char *argv[])
{
	const char *kernel, *initrd;
	void *kernel_data, *initrd_data;
	struct initramfs *rd;
	size_t kernel_len, initrd_len;
	char cmdline[1024];
	uint32_t mem_limit = 0;
	uint16_t video_mode = 0;
	int i;
	unsigned p;
	char _b[64];

#define pause() (fgets(_b, sizeof _b, stdin))

	s_cpu cpu;

	openconsole(&dev_stdcon_r, &dev_stdcon_w);

	for (i = 0; i < argc; i++) {
		printf("argument %d: '%s'\n", i, argv[i]);
	}
	pause();

	if (argc < 5) {
		fprintf(stderr, "missing options, usage:\n"
				"  l23or64 <32b kernel> <32b initrd> \\"
				"          <64b kernel> <64b initrd> \\"
				"          [kernel arguments]\n");
		return 1;
	}

	detect_cpu(&cpu);

	if (cpu.flags.lm) {
		initrd = argv[4];
		kernel = argv[3];
	} else {
		initrd = argv[2];
		kernel = argv[1];
	}

	printf("kernel: %s\ninitrd: %s\n", kernel, initrd);

	cmdline[0] = '\0';
	for (i = 5, p = 0; i < argc; i++) {
		unsigned l = strlen(argv[i]);
		if ((p + l + 1) >= sizeof cmdline) {
			fprintf(stderr, "command line exceeds internal "
					"buffers, trimmed.\n");
			break;
		}
		memcpy(cmdline + p, argv[i], l);
		cmdline[p + l] = ' ';
		p += l + 1;

		/* check for mem= or video= */
		if (!strncmp(argv[i], "mem=", 4)) {
			char *suf;

			mem_limit = strtoul(argv[i] + 4, &suf, 0);

			switch (toupper(*suf)) {
				case 'g':
					mem_limit <<= 10;
				case 'm':
					mem_limit <<= 10;
				case 'k':
					mem_limit <<= 10;
			}
		} else if (!strncmp(argv[i], "video=", 6)) {
			video_mode = strtoul(argv[i] + 6, NULL, 0);
		}
	}
	cmdline[p] = '\0';

	printf("cmdline: %s\n", cmdline);
	pause();
	i = loadfile(kernel, &kernel_data, &kernel_len);
	printf("load %s: %d (%d)\n", kernel, i, kernel_len);
	if (i) {
		fprintf(stderr, "kernel %s failed to load\n", kernel);
		return 1;
	}

	if (!(rd = initramfs_init())) {
		fprintf(stderr, "couldn't initialize initramfs\n");
		return 1;
	}

	i = loadfile(initrd, &initrd_data, &initrd_len);
	printf("load %s: %d (%d)\n", initrd, i, initrd_len);
	if (i) {
		fprintf(stderr, "initrd %s failed to load\n", initrd);
		return 1;
	}
	if (initramfs_add_data(rd, initrd_data, initrd_len, initrd_len, 4)) {
		fprintf(stderr, "couldn't add initrd data\n");
		return 1;
	}

	printf("initramfs_len: %d\n", rd->len);
	printf("initramfs_len: %d\n", rd->data_len);
	printf("initramfs_len: %d\n", rd->next->len);
	printf("initramfs_len: %d\n", rd->next->data_len);
	pause();
	syslinux_boot_linux(kernel_data, kernel_len, rd, cmdline,
			video_mode, mem_limit);

	return 0;
}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL:
<http://www.zytor.com/pipermail/syslinux/attachments/20070426/4f7892ab/attachment.sig>

On Thu, Apr 26, 2007 at 08:38:04PM +0100, Luciano Miguel Ferreira Rocha
wrote:
> PS: not gpg-signed because syslinux at zytor.com thinks that's
suspicious.
Oops, force of habit, but this time it didn't go to the moderator (or he
was fast), so this is good news for me.

-- 
lfr
0/0

Luciano Miguel Ferreira Rocha wrote:
> 
> The first was that syslinux_boot_linux didn't work for me. Both the
> command line and initrd data was garbage. The code I was developing is
> attached as l32or64_linux.c
> 
When you say garbage, are you talking about it being correct before
booting and then it being crap, or is it crap only after booting the kernel.

A lot of your code there is just plain wrong.  I suggest using more of
the code from com32/modules/linux.c including the command-line parsing
and using initramfs_load_archive().

	-hpa