bootm.c

uboot详细解读可用启动引导LINUX2.6内核

/*
 * (C) Copyright 2008 Semihalf
 *
 * (C) Copyright 2000-2006
 * Wolfgang Denk, DENX Software Engineering, [e-mail].
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 <common.h>
#include <watchdog.h>
#include <command.h>
#include <image.h>
#include <malloc.h>
#include <zlib.h>
#include <bzlib.h>
#include <environment.h>
#include <asm/byteorder.h>

#if defined(CONFIG_OF_LIBFDT)
#include <fdt.h>
#include <libfdt.h>
#include <fdt_support.h>

static void fdt_error (const char *msg);
static int boot_get_fdt (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
		bootm_headers_t *images, char **of_flat_tree, ulong *of_size);
static int boot_relocate_fdt (struct lmb *lmb, ulong bootmap_base,
		cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
		char **of_flat_tree, ulong *of_size);
#endif

#ifdef CFG_INIT_RAM_LOCK
#include <asm/cache.h>
#endif

#ifndef CFG_FDT_PAD
#define CFG_FDT_PAD 0x3000
#endif

DECLARE_GLOBAL_DATA_PTR;

extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
extern ulong get_effective_memsize(void);
static ulong get_sp (void);
static void set_clocks_in_mhz (bd_t *kbd);

#ifndef CFG_LINUX_LOWMEM_MAX_SIZE
#define CFG_LINUX_LOWMEM_MAX_SIZE	(768*1024*1024)
#endif

void  __attribute__((noinline))
do_bootm_linux(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
		bootm_headers_t *images)
{
	ulong	sp;

	ulong	initrd_start, initrd_end;
	ulong	rd_data_start, rd_data_end, rd_len;
	ulong	size;
	phys_size_t bootm_size;

	ulong	cmd_start, cmd_end, bootmap_base;
	bd_t	*kbd;
	ulong	ep = 0;
	void	(*kernel)(bd_t *, ulong, ulong, ulong, ulong);
	int	ret;
	ulong	of_size = 0;
	struct lmb *lmb = images->lmb;

#if defined(CONFIG_OF_LIBFDT)
	char	*of_flat_tree = NULL;
#endif

	bootmap_base = getenv_bootm_low();
	bootm_size = getenv_bootm_size();

#ifdef DEBUG
	if (((u64)bootmap_base + bootm_size) >
	    (CFG_SDRAM_BASE + (u64)gd->ram_size))
		puts("WARNING: bootm_low + bootm_size exceed total memory\n");
	if ((bootmap_base + bootm_size) > get_effective_memsize())
		puts("WARNING: bootm_low + bootm_size exceed eff. memory\n");
#endif

	size = min(bootm_size, get_effective_memsize());
	size = min(size, CFG_LINUX_LOWMEM_MAX_SIZE);

	if (size < bootm_size) {
		ulong base = bootmap_base + size;
		printf("WARNING: adjusting available memory to %lx\n", size);
		lmb_reserve(lmb, base, bootm_size - size);
	}

	/*
	 * Booting a (Linux) kernel image
	 *
	 * Allocate space for command line and board info - the
	 * address should be as high as possible within the reach of
	 * the kernel (see CFG_BOOTMAPSZ settings), but in unused
	 * memory, which means far enough below the current stack
	 * pointer.
	 */
	sp = get_sp();
	debug ("## Current stack ends at 0x%08lx\n", sp);

	/* adjust sp by 1K to be safe */
	sp -= 1024;
	lmb_reserve(lmb, sp, (CFG_SDRAM_BASE + get_effective_memsize() - sp));

#if defined(CONFIG_OF_LIBFDT)
	/* find flattened device tree */
	ret = boot_get_fdt (cmdtp, flag, argc, argv, images, &of_flat_tree, &of_size);

	if (ret)
		goto error;
#endif

	if (!of_size) {
		/* allocate space and init command line */
		ret = boot_get_cmdline (lmb, &cmd_start, &cmd_end, bootmap_base);
		if (ret) {
			puts("ERROR with allocation of cmdline\n");
			goto error;
		}

		/* allocate space for kernel copy of board info */
		ret = boot_get_kbd (lmb, &kbd, bootmap_base);
		if (ret) {
			puts("ERROR with allocation of kernel bd\n");
			goto error;
		}
		set_clocks_in_mhz(kbd);
	}

	/* find kernel entry point */
	if (images->legacy_hdr_valid) {
		ep = image_get_ep (&images->legacy_hdr_os_copy);
#if defined(CONFIG_FIT)
	} else if (images->fit_uname_os) {
		ret = fit_image_get_entry (images->fit_hdr_os,
				images->fit_noffset_os, &ep);
		if (ret) {
			puts ("Can't get entry point property!\n");
			goto error;
		}
#endif
	} else {
		puts ("Could not find kernel entry point!\n");
		goto error;
	}
	kernel = (void (*)(bd_t *, ulong, ulong, ulong, ulong))ep;

	/* find ramdisk */
	ret = boot_get_ramdisk (argc, argv, images, IH_ARCH_PPC,
			&rd_data_start, &rd_data_end);
	if (ret)
		goto error;

	rd_len = rd_data_end - rd_data_start;

#if defined(CONFIG_OF_LIBFDT)
	ret = boot_relocate_fdt (lmb, bootmap_base,
		cmdtp, flag, argc, argv, &of_flat_tree, &of_size);

	/*
	 * Add the chosen node if it doesn't exist, add the env and bd_t
	 * if the user wants it (the logic is in the subroutines).
	 */
	if (of_size) {
		/* pass in dummy initrd info, we'll fix up later */
		if (fdt_chosen(of_flat_tree, rd_data_start, rd_data_end, 0) < 0) {
			fdt_error ("/chosen node create failed");
			goto error;
		}
#ifdef CONFIG_OF_BOARD_SETUP
		/* Call the board-specific fixup routine */
		ft_board_setup(of_flat_tree, gd->bd);
#endif
	}

	/* Fixup the fdt memreserve now that we know how big it is */
	if (of_flat_tree) {
		int j;
		uint64_t addr, size;
		int total = fdt_num_mem_rsv(of_flat_tree);
		uint actualsize;

		for (j = 0; j < total; j++) {
			fdt_get_mem_rsv(of_flat_tree, j, &addr, &size);
			if (addr == (uint64_t)(u32)of_flat_tree) {
				fdt_del_mem_rsv(of_flat_tree, j);
				break;
			}
		}

		/* Delete the old LMB reservation */
		lmb_free(lmb, (phys_addr_t)(u32)of_flat_tree,
				(phys_size_t)fdt_totalsize(of_flat_tree));

		/* Calculate the actual size of the fdt */
		actualsize = fdt_off_dt_strings(of_flat_tree) +
			fdt_size_dt_strings(of_flat_tree);

		/* Make it so the fdt ends on a page boundary */
		actualsize = ALIGN(actualsize, 0x1000);
		actualsize = actualsize - ((uint)of_flat_tree & 0xfff);

		/* Change the fdt header to reflect the correct size */
		fdt_set_totalsize(of_flat_tree, actualsize);
		of_size = actualsize;

		/* Add the new reservation */
		ret = fdt_add_mem_rsv(of_flat_tree, (uint)of_flat_tree,
				of_size);

		/* Create a new LMB reservation */
		lmb_reserve(lmb, (ulong)of_flat_tree, of_size);
	}
#endif	/* CONFIG_OF_LIBFDT */

	ret = boot_ramdisk_high (lmb, rd_data_start, rd_len, &initrd_start, &initrd_end);
	if (ret)
		goto error;

#if defined(CONFIG_OF_LIBFDT)
	/* fixup the initrd now that we know where it should be */
	if ((of_flat_tree) && (initrd_start && initrd_end)) {
		uint64_t addr, size;
		int  total = fdt_num_mem_rsv(of_flat_tree);
		int  j;

		/* Look for the dummy entry and delete it */
		for (j = 0; j < total; j++) {
			fdt_get_mem_rsv(of_flat_tree, j, &addr, &size);
			if (addr == rd_data_start) {
				fdt_del_mem_rsv(of_flat_tree, j);
				break;
			}
		}

		ret = fdt_add_mem_rsv(of_flat_tree, initrd_start,
					initrd_end - initrd_start + 1);
		if (ret < 0) {
			printf("fdt_chosen: %s\n", fdt_strerror(ret));
			goto error;
		}

		do_fixup_by_path_u32(of_flat_tree, "/chosen",
					"linux,initrd-start", initrd_start, 0);
		do_fixup_by_path_u32(of_flat_tree, "/chosen",
					"linux,initrd-end", initrd_end, 0);
	}
#endif
	debug ("## Transferring control to Linux (at address %08lx) ...\n",
		(ulong)kernel);

	show_boot_progress (15);

#if defined(CFG_INIT_RAM_LOCK) && !defined(CONFIG_E500)
	unlock_ram_in_cache();
#endif

#if defined(CONFIG_OF_LIBFDT)
	if (of_flat_tree) {	/* device tree; boot new style */
		/*
		 * Linux Kernel Parameters (passing device tree):
		 *   r3: pointer to the fdt, followed by the board info data
		 *   r4: physical pointer to the kernel itself
		 *   r5: NULL
		 *   r6: NULL
		 *   r7: NULL
		 */
		debug ("   Booting using OF flat tree...\n");
		(*kernel) ((bd_t *)of_flat_tree, (ulong)kernel, 0, 0, 0);
		/* does not return */
	} else
#endif
	{
		/*
		 * Linux Kernel Parameters (passing board info data):
		 *   r3: ptr to board info data
		 *   r4: initrd_start or 0 if no initrd
		 *   r5: initrd_end - unused if r4 is 0
		 *   r6: Start of command line string
		 *   r7: End   of command line string
		 */
		debug ("   Booting using board info...\n");
		(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
		/* does not return */
	}
	return ;

error:
	do_reset (cmdtp, flag, argc, argv);
	return ;
}

static ulong get_sp (void)
{
	ulong sp;

	asm( "mr %0,1": "=r"(sp) : );
	return sp;
}

static void set_clocks_in_mhz (bd_t *kbd)
{
	char	*s;

	if ((s = getenv ("clocks_in_mhz")) != NULL) {
		/* convert all clock information to MHz */
		kbd->bi_intfreq /= 1000000L;
		kbd->bi_busfreq /= 1000000L;
#if defined(CONFIG_MPC8220)
		kbd->bi_inpfreq /= 1000000L;
		kbd->bi_pcifreq /= 1000000L;
		kbd->bi_pevfreq /= 1000000L;
		kbd->bi_flbfreq /= 1000000L;
		kbd->bi_vcofreq /= 1000000L;
#endif
#if defined(CONFIG_CPM2)
		kbd->bi_cpmfreq /= 1000000L;
		kbd->bi_brgfreq /= 1000000L;
		kbd->bi_sccfreq /= 1000000L;
		kbd->bi_vco	/= 1000000L;
#endif
#if defined(CONFIG_MPC5xxx)
		kbd->bi_ipbfreq /= 1000000L;
		kbd->bi_pcifreq /= 1000000L;
#endif /* CONFIG_MPC5xxx */
	}
}

#if defined(CONFIG_OF_LIBFDT)
static void fdt_error (const char *msg)
{
	puts ("ERROR: ");
	puts (msg);
	puts (" - must RESET the board to recover.\n");
}

static image_header_t *image_get_fdt (ulong fdt_addr)
{
	image_header_t *fdt_hdr = (image_header_t *)fdt_addr;

	image_print_contents (fdt_hdr);

	puts ("   Verifying Checksum ... ");
	if (!image_check_hcrc (fdt_hdr)) {
		fdt_error ("fdt header checksum invalid");
		return NULL;
	}

	if (!image_check_dcrc (fdt_hdr)) {
		fdt_error ("fdt checksum invalid");
		return NULL;
	}
	puts ("OK\n");

	if (!image_check_type (fdt_hdr, IH_TYPE_FLATDT)) {
		fdt_error ("uImage is not a fdt");
		return NULL;
	}
	if (image_get_comp (fdt_hdr) != IH_COMP_NONE) {
		fdt_error ("uImage is compressed");
		return NULL;
	}
	if (fdt_check_header ((char *)image_get_data (fdt_hdr)) != 0) {
		fdt_error ("uImage data is not a fdt");
		return NULL;
	}
	return fdt_hdr;
}

/**
 * fit_check_fdt - verify FIT format FDT subimage
 * @fit_hdr: pointer to the FIT  header
 * fdt_noffset: FDT subimage node offset within FIT image
 * @verify: data CRC verification flag
 *
 * fit_check_fdt() verifies integrity of the FDT subimage and from
 * specified FIT image.
 *
 * returns:
 *     1, on success
 *     0, on failure
 */
#if defined(CONFIG_FIT)