bootm: Split out code from cmd_bootm.c

This file has code in three different categories:
- Command processing
- OS-specific boot code
- Locating images and setting up to boot

Only the first category really belongs in a file called cmd_bootm.c.

Leave the command processing code where it is. Split out the OS-specific
boot code into bootm_os.c. Split out the other code into bootm.c

Header files and extern declarations are tidied but otherwise no code
changes are made, to make it easier to review.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 812 insertions, 0 deletions

diff --git a/common/bootm.c b/common/bootm.c
new file mode 100644
index 0000000..27a7f02
--- /dev/null
+++ b/common/bootm.c
@@ -0,0 +1,812 @@
+/*
+ * (C) Copyright 2000-2009
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <bootm.h>
+#include <bzlib.h>
+#include <image.h>
+#include <fdt_support.h>
+#include <lmb.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <linux/lzo.h>
+#include <lzma/LzmaTypes.h>
+#include <lzma/LzmaDec.h>
+#include <lzma/LzmaTools.h>
+
+#if defined(CONFIG_CMD_USB)
+#include <usb.h>
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifndef CONFIG_SYS_BOOTM_LEN
+/* use 8MByte as default max gunzip size */
+#define CONFIG_SYS_BOOTM_LEN	0x800000
+#endif
+
+#define IH_INITRD_ARCH IH_ARCH_DEFAULT
+
+static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
+				   char * const argv[], bootm_headers_t *images,
+				   ulong *os_data, ulong *os_len);
+
+#ifdef CONFIG_LMB
+static void boot_start_lmb(bootm_headers_t *images)
+{
+	ulong		mem_start;
+	phys_size_t	mem_size;
+
+	lmb_init(&images->lmb);
+
+	mem_start = getenv_bootm_low();
+	mem_size = getenv_bootm_size();
+
+	lmb_add(&images->lmb, (phys_addr_t)mem_start, mem_size);
+
+	arch_lmb_reserve(&images->lmb);
+	board_lmb_reserve(&images->lmb);
+}
+#else
+#define lmb_reserve(lmb, base, size)
+static inline void boot_start_lmb(bootm_headers_t *images) { }
+#endif
+
+static int bootm_start(cmd_tbl_t *cmdtp, int flag, int argc,
+		       char * const argv[])
+{
+	memset((void *)&images, 0, sizeof(images));
+	images.verify = getenv_yesno("verify");
+
+	boot_start_lmb(&images);
+
+	bootstage_mark_name(BOOTSTAGE_ID_BOOTM_START, "bootm_start");
+	images.state = BOOTM_STATE_START;
+
+	return 0;
+}
+
+static int bootm_find_os(cmd_tbl_t *cmdtp, int flag, int argc,
+			 char * const argv[])
+{
+	const void *os_hdr;
+	bool ep_found = false;
+
+	/* get kernel image header, start address and length */
+	os_hdr = boot_get_kernel(cmdtp, flag, argc, argv,
+			&images, &images.os.image_start, &images.os.image_len);
+	if (images.os.image_len == 0) {
+		puts("ERROR: can't get kernel image!\n");
+		return 1;
+	}
+
+	/* get image parameters */
+	switch (genimg_get_format(os_hdr)) {
+#if defined(CONFIG_IMAGE_FORMAT_LEGACY)
+	case IMAGE_FORMAT_LEGACY:
+		images.os.type = image_get_type(os_hdr);
+		images.os.comp = image_get_comp(os_hdr);
+		images.os.os = image_get_os(os_hdr);
+
+		images.os.end = image_get_image_end(os_hdr);
+		images.os.load = image_get_load(os_hdr);
+		break;
+#endif
+#if defined(CONFIG_FIT)
+	case IMAGE_FORMAT_FIT:
+		if (fit_image_get_type(images.fit_hdr_os,
+				       images.fit_noffset_os,
+				       &images.os.type)) {
+			puts("Can't get image type!\n");
+			bootstage_error(BOOTSTAGE_ID_FIT_TYPE);
+			return 1;
+		}
+
+		if (fit_image_get_comp(images.fit_hdr_os,
+				       images.fit_noffset_os,
+				       &images.os.comp)) {
+			puts("Can't get image compression!\n");
+			bootstage_error(BOOTSTAGE_ID_FIT_COMPRESSION);
+			return 1;
+		}
+
+		if (fit_image_get_os(images.fit_hdr_os, images.fit_noffset_os,
+				     &images.os.os)) {
+			puts("Can't get image OS!\n");
+			bootstage_error(BOOTSTAGE_ID_FIT_OS);
+			return 1;
+		}
+
+		images.os.end = fit_get_end(images.fit_hdr_os);
+
+		if (fit_image_get_load(images.fit_hdr_os, images.fit_noffset_os,
+				       &images.os.load)) {
+			puts("Can't get image load address!\n");
+			bootstage_error(BOOTSTAGE_ID_FIT_LOADADDR);
+			return 1;
+		}
+		break;
+#endif
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	case IMAGE_FORMAT_ANDROID:
+		images.os.type = IH_TYPE_KERNEL;
+		images.os.comp = IH_COMP_NONE;
+		images.os.os = IH_OS_LINUX;
+		images.ep = images.os.load;
+		ep_found = true;
+
+		images.os.end = android_image_get_end(os_hdr);
+		images.os.load = android_image_get_kload(os_hdr);
+		break;
+#endif
+	default:
+		puts("ERROR: unknown image format type!\n");
+		return 1;
+	}
+
+	/* find kernel entry point */
+	if (images.legacy_hdr_valid) {
+		images.ep = image_get_ep(&images.legacy_hdr_os_copy);
+#if defined(CONFIG_FIT)
+	} else if (images.fit_uname_os) {
+		int ret;
+
+		ret = fit_image_get_entry(images.fit_hdr_os,
+					  images.fit_noffset_os, &images.ep);
+		if (ret) {
+			puts("Can't get entry point property!\n");
+			return 1;
+		}
+#endif
+	} else if (!ep_found) {
+		puts("Could not find kernel entry point!\n");
+		return 1;
+	}
+
+	if (images.os.type == IH_TYPE_KERNEL_NOLOAD) {
+		images.os.load = images.os.image_start;
+		images.ep += images.os.load;
+	}
+
+	images.os.start = (ulong)os_hdr;
+
+	return 0;
+}
+
+static int bootm_find_ramdisk(int flag, int argc, char * const argv[])
+{
+	int ret;
+
+	/* find ramdisk */
+	ret = boot_get_ramdisk(argc, argv, &images, IH_INITRD_ARCH,
+			       &images.rd_start, &images.rd_end);
+	if (ret) {
+		puts("Ramdisk image is corrupt or invalid\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+#if defined(CONFIG_OF_LIBFDT)
+static int bootm_find_fdt(int flag, int argc, char * const argv[])
+{
+	int ret;
+
+	/* find flattened device tree */
+	ret = boot_get_fdt(flag, argc, argv, IH_ARCH_DEFAULT, &images,
+			   &images.ft_addr, &images.ft_len);
+	if (ret) {
+		puts("Could not find a valid device tree\n");
+		return 1;
+	}
+
+	set_working_fdt_addr(images.ft_addr);
+
+	return 0;
+}
+#endif
+
+int bootm_find_ramdisk_fdt(int flag, int argc, char * const argv[])
+{
+	if (bootm_find_ramdisk(flag, argc, argv))
+		return 1;
+
+#if defined(CONFIG_OF_LIBFDT)
+	if (bootm_find_fdt(flag, argc, argv))
+		return 1;
+#endif
+
+	return 0;
+}
+
+static int bootm_find_other(cmd_tbl_t *cmdtp, int flag, int argc,
+			    char * const argv[])
+{
+	if (((images.os.type == IH_TYPE_KERNEL) ||
+	     (images.os.type == IH_TYPE_KERNEL_NOLOAD) ||
+	     (images.os.type == IH_TYPE_MULTI)) &&
+	    (images.os.os == IH_OS_LINUX ||
+		 images.os.os == IH_OS_VXWORKS))
+		return bootm_find_ramdisk_fdt(flag, argc, argv);
+
+	return 0;
+}
+
+static int bootm_load_os(bootm_headers_t *images, unsigned long *load_end,
+			 int boot_progress)
+{
+	image_info_t os = images->os;
+	uint8_t comp = os.comp;
+	ulong load = os.load;
+	ulong blob_start = os.start;
+	ulong blob_end = os.end;
+	ulong image_start = os.image_start;
+	ulong image_len = os.image_len;
+	__maybe_unused uint unc_len = CONFIG_SYS_BOOTM_LEN;
+	int no_overlap = 0;
+	void *load_buf, *image_buf;
+#if defined(CONFIG_LZMA) || defined(CONFIG_LZO)
+	int ret;
+#endif /* defined(CONFIG_LZMA) || defined(CONFIG_LZO) */
+
+	const char *type_name = genimg_get_type_name(os.type);
+
+	load_buf = map_sysmem(load, unc_len);
+	image_buf = map_sysmem(image_start, image_len);
+	switch (comp) {
+	case IH_COMP_NONE:
+		if (load == image_start) {
+			printf("   XIP %s ... ", type_name);
+			no_overlap = 1;
+		} else {
+			printf("   Loading %s ... ", type_name);
+			memmove_wd(load_buf, image_buf, image_len, CHUNKSZ);
+		}
+		*load_end = load + image_len;
+		break;
+#ifdef CONFIG_GZIP
+	case IH_COMP_GZIP:
+		printf("   Uncompressing %s ... ", type_name);
+		if (gunzip(load_buf, unc_len, image_buf, &image_len) != 0) {
+			puts("GUNZIP: uncompress, out-of-mem or overwrite error - must RESET board to recover\n");
+			if (boot_progress)
+				bootstage_error(BOOTSTAGE_ID_DECOMP_IMAGE);
+			return BOOTM_ERR_RESET;
+		}
+
+		*load_end = load + image_len;
+		break;
+#endif /* CONFIG_GZIP */
+#ifdef CONFIG_BZIP2
+	case IH_COMP_BZIP2:
+		printf("   Uncompressing %s ... ", type_name);
+		/*
+		 * If we've got less than 4 MB of malloc() space,
+		 * use slower decompression algorithm which requires
+		 * at most 2300 KB of memory.
+		 */
+		int i = BZ2_bzBuffToBuffDecompress(load_buf, &unc_len,
+			image_buf, image_len,
+			CONFIG_SYS_MALLOC_LEN < (4096 * 1024), 0);
+		if (i != BZ_OK) {
+			printf("BUNZIP2: uncompress or overwrite error %d - must RESET board to recover\n",
+			       i);
+			if (boot_progress)
+				bootstage_error(BOOTSTAGE_ID_DECOMP_IMAGE);
+			return BOOTM_ERR_RESET;
+		}
+
+		*load_end = load + unc_len;
+		break;
+#endif /* CONFIG_BZIP2 */
+#ifdef CONFIG_LZMA
+	case IH_COMP_LZMA: {
+		SizeT lzma_len = unc_len;
+		printf("   Uncompressing %s ... ", type_name);
+
+		ret = lzmaBuffToBuffDecompress(load_buf, &lzma_len,
+					       image_buf, image_len);
+		unc_len = lzma_len;
+		if (ret != SZ_OK) {
+			printf("LZMA: uncompress or overwrite error %d - must RESET board to recover\n",
+			       ret);
+			bootstage_error(BOOTSTAGE_ID_DECOMP_IMAGE);
+			return BOOTM_ERR_RESET;
+		}
+		*load_end = load + unc_len;
+		break;
+	}
+#endif /* CONFIG_LZMA */
+#ifdef CONFIG_LZO
+	case IH_COMP_LZO: {
+		size_t size = unc_len;
+
+		printf("   Uncompressing %s ... ", type_name);
+
+		ret = lzop_decompress(image_buf, image_len, load_buf, &size);
+		if (ret != LZO_E_OK) {
+			printf("LZO: uncompress or overwrite error %d - must RESET board to recover\n",
+			       ret);
+			if (boot_progress)
+				bootstage_error(BOOTSTAGE_ID_DECOMP_IMAGE);
+			return BOOTM_ERR_RESET;
+		}
+
+		*load_end = load + size;
+		break;
+	}
+#endif /* CONFIG_LZO */
+	default:
+		printf("Unimplemented compression type %d\n", comp);
+		return BOOTM_ERR_UNIMPLEMENTED;
+	}
+
+	flush_cache(load, (*load_end - load) * sizeof(ulong));
+
+	puts("OK\n");
+	debug("   kernel loaded at 0x%08lx, end = 0x%08lx\n", load, *load_end);
+	bootstage_mark(BOOTSTAGE_ID_KERNEL_LOADED);
+
+	if (!no_overlap && (load < blob_end) && (*load_end > blob_start)) {
+		debug("images.os.start = 0x%lX, images.os.end = 0x%lx\n",
+		      blob_start, blob_end);
+		debug("images.os.load = 0x%lx, load_end = 0x%lx\n", load,
+		      *load_end);
+
+		/* Check what type of image this is. */
+		if (images->legacy_hdr_valid) {
+			if (image_get_type(&images->legacy_hdr_os_copy)
+					== IH_TYPE_MULTI)
+				puts("WARNING: legacy format multi component image overwritten\n");
+			return BOOTM_ERR_OVERLAP;
+		} else {
+			puts("ERROR: new format image overwritten - must RESET the board to recover\n");
+			bootstage_error(BOOTSTAGE_ID_OVERWRITTEN);
+			return BOOTM_ERR_RESET;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * bootm_disable_interrupts() - Disable interrupts in preparation for load/boot
+ *
+ * @return interrupt flag (0 if interrupts were disabled, non-zero if they were
+ *	enabled)
+ */
+ulong bootm_disable_interrupts(void)
+{
+	ulong iflag;
+
+	/*
+	 * We have reached the point of no return: we are going to
+	 * overwrite all exception vector code, so we cannot easily
+	 * recover from any failures any more...
+	 */
+	iflag = disable_interrupts();
+#ifdef CONFIG_NETCONSOLE
+	/* Stop the ethernet stack if NetConsole could have left it up */
+	eth_halt();
+	eth_unregister(eth_get_dev());
+#endif
+
+#if defined(CONFIG_CMD_USB)
+	/*
+	 * turn off USB to prevent the host controller from writing to the
+	 * SDRAM while Linux is booting. This could happen (at least for OHCI
+	 * controller), because the HCCA (Host Controller Communication Area)
+	 * lies within the SDRAM and the host controller writes continously to
+	 * this area (as busmaster!). The HccaFrameNumber is for example
+	 * updated every 1 ms within the HCCA structure in SDRAM! For more
+	 * details see the OpenHCI specification.
+	 */
+	usb_stop();
+#endif
+	return iflag;
+}
+
+#if defined(CONFIG_SILENT_CONSOLE) && !defined(CONFIG_SILENT_U_BOOT_ONLY)
+
+#define CONSOLE_ARG     "console="
+#define CONSOLE_ARG_LEN (sizeof(CONSOLE_ARG) - 1)
+
+static void fixup_silent_linux(void)
+{
+	char *buf;
+	const char *env_val;
+	char *cmdline = getenv("bootargs");
+	int want_silent;
+
+	/*
+	 * Only fix cmdline when requested. The environment variable can be:
+	 *
+	 *	no - we never fixup
+	 *	yes - we always fixup
+	 *	unset - we rely on the console silent flag
+	 */
+	want_silent = getenv_yesno("silent_linux");
+	if (want_silent == 0)
+		return;
+	else if (want_silent == -1 && !(gd->flags & GD_FLG_SILENT))
+		return;
+
+	debug("before silent fix-up: %s\n", cmdline);
+	if (cmdline && (cmdline[0] != '\0')) {
+		char *start = strstr(cmdline, CONSOLE_ARG);
+
+		/* Allocate space for maximum possible new command line */
+		buf = malloc(strlen(cmdline) + 1 + CONSOLE_ARG_LEN + 1);
+		if (!buf) {
+			debug("%s: out of memory\n", __func__);
+			return;
+		}
+
+		if (start) {
+			char *end = strchr(start, ' ');
+			int num_start_bytes = start - cmdline + CONSOLE_ARG_LEN;
+
+			strncpy(buf, cmdline, num_start_bytes);
+			if (end)
+				strcpy(buf + num_start_bytes, end);
+			else
+				buf[num_start_bytes] = '\0';
+		} else {
+			sprintf(buf, "%s %s", cmdline, CONSOLE_ARG);
+		}
+		env_val = buf;
+	} else {
+		buf = NULL;
+		env_val = CONSOLE_ARG;
+	}
+
+	setenv("bootargs", env_val);
+	debug("after silent fix-up: %s\n", env_val);
+	free(buf);
+}
+#endif /* CONFIG_SILENT_CONSOLE */
+
+/**
+ * Execute selected states of the bootm command.
+ *
+ * Note the arguments to this state must be the first argument, Any 'bootm'
+ * or sub-command arguments must have already been taken.
+ *
+ * Note that if states contains more than one flag it MUST contain
+ * BOOTM_STATE_START, since this handles and consumes the command line args.
+ *
+ * Also note that aside from boot_os_fn functions and bootm_load_os no other
+ * functions we store the return value of in 'ret' may use a negative return
+ * value, without special handling.
+ *
+ * @param cmdtp		Pointer to bootm command table entry
+ * @param flag		Command flags (CMD_FLAG_...)
+ * @param argc		Number of subcommand arguments (0 = no arguments)
+ * @param argv		Arguments
+ * @param states	Mask containing states to run (BOOTM_STATE_...)
+ * @param images	Image header information
+ * @param boot_progress 1 to show boot progress, 0 to not do this
+ * @return 0 if ok, something else on error. Some errors will cause this
+ *	function to perform a reboot! If states contains BOOTM_STATE_OS_GO
+ *	then the intent is to boot an OS, so this function will not return
+ *	unless the image type is standalone.
+ */
+int do_bootm_states(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
+		    int states, bootm_headers_t *images, int boot_progress)
+{
+	boot_os_fn *boot_fn;
+	ulong iflag = 0;
+	int ret = 0, need_boot_fn;
+
+	images->state |= states;
+
+	/*
+	 * Work through the states and see how far we get. We stop on
+	 * any error.
+	 */
+	if (states & BOOTM_STATE_START)
+		ret = bootm_start(cmdtp, flag, argc, argv);
+
+	if (!ret && (states & BOOTM_STATE_FINDOS))
+		ret = bootm_find_os(cmdtp, flag, argc, argv);
+
+	if (!ret && (states & BOOTM_STATE_FINDOTHER)) {
+		ret = bootm_find_other(cmdtp, flag, argc, argv);
+		argc = 0;	/* consume the args */
+	}
+
+	/* Load the OS */
+	if (!ret && (states & BOOTM_STATE_LOADOS)) {
+		ulong load_end;
+
+		iflag = bootm_disable_interrupts();
+		ret = bootm_load_os(images, &load_end, 0);
+		if (ret == 0)
+			lmb_reserve(&images->lmb, images->os.load,
+				    (load_end - images->os.load));
+		else if (ret && ret != BOOTM_ERR_OVERLAP)
+			goto err;
+		else if (ret == BOOTM_ERR_OVERLAP)
+			ret = 0;
+#if defined(CONFIG_SILENT_CONSOLE) && !defined(CONFIG_SILENT_U_BOOT_ONLY)
+		if (images->os.os == IH_OS_LINUX)
+			fixup_silent_linux();
+#endif
+	}
+
+	/* Relocate the ramdisk */
+#ifdef CONFIG_SYS_BOOT_RAMDISK_HIGH
+	if (!ret && (states & BOOTM_STATE_RAMDISK)) {
+		ulong rd_len = images->rd_end - images->rd_start;
+
+		ret = boot_ramdisk_high(&images->lmb, images->rd_start,
+			rd_len, &images->initrd_start, &images->initrd_end);
+		if (!ret) {
+			setenv_hex("initrd_start", images->initrd_start);
+			setenv_hex("initrd_end", images->initrd_end);
+		}
+	}
+#endif
+#if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_LMB)
+	if (!ret && (states & BOOTM_STATE_FDT)) {
+		boot_fdt_add_mem_rsv_regions(&images->lmb, images->ft_addr);
+		ret = boot_relocate_fdt(&images->lmb, &images->ft_addr,
+					&images->ft_len);
+	}
+#endif
+
+	/* From now on, we need the OS boot function */
+	if (ret)
+		return ret;
+	boot_fn = bootm_os_get_boot_func(images->os.os);
+	need_boot_fn = states & (BOOTM_STATE_OS_CMDLINE |
+			BOOTM_STATE_OS_BD_T | BOOTM_STATE_OS_PREP |
+			BOOTM_STATE_OS_FAKE_GO | BOOTM_STATE_OS_GO);
+	if (boot_fn == NULL && need_boot_fn) {
+		if (iflag)
+			enable_interrupts();
+		printf("ERROR: booting os '%s' (%d) is not supported\n",
+		       genimg_get_os_name(images->os.os), images->os.os);
+		bootstage_error(BOOTSTAGE_ID_CHECK_BOOT_OS);
+		return 1;
+	}
+
+	/* Call various other states that are not generally used */
+	if (!ret && (states & BOOTM_STATE_OS_CMDLINE))
+		ret = boot_fn(BOOTM_STATE_OS_CMDLINE, argc, argv, images);
+	if (!ret && (states & BOOTM_STATE_OS_BD_T))
+		ret = boot_fn(BOOTM_STATE_OS_BD_T, argc, argv, images);
+	if (!ret && (states & BOOTM_STATE_OS_PREP))
+		ret = boot_fn(BOOTM_STATE_OS_PREP, argc, argv, images);
+
+#ifdef CONFIG_TRACE
+	/* Pretend to run the OS, then run a user command */
+	if (!ret && (states & BOOTM_STATE_OS_FAKE_GO)) {
+		char *cmd_list = getenv("fakegocmd");
+
+		ret = boot_selected_os(argc, argv, BOOTM_STATE_OS_FAKE_GO,
+				images, boot_fn);
+		if (!ret && cmd_list)
+			ret = run_command_list(cmd_list, -1, flag);
+	}
+#endif
+
+	/* Check for unsupported subcommand. */
+	if (ret) {
+		puts("subcommand not supported\n");
+		return ret;
+	}
+
+	/* Now run the OS! We hope this doesn't return */
+	if (!ret && (states & BOOTM_STATE_OS_GO))
+		ret = boot_selected_os(argc, argv, BOOTM_STATE_OS_GO,
+				images, boot_fn);
+
+	/* Deal with any fallout */
+err:
+	if (iflag)
+		enable_interrupts();
+
+	if (ret == BOOTM_ERR_UNIMPLEMENTED)
+		bootstage_error(BOOTSTAGE_ID_DECOMP_UNIMPL);
+	else if (ret == BOOTM_ERR_RESET)
+		do_reset(cmdtp, flag, argc, argv);
+
+	return ret;
+}
+
+#if defined(CONFIG_IMAGE_FORMAT_LEGACY)
+/**
+ * image_get_kernel - verify legacy format kernel image
+ * @img_addr: in RAM address of the legacy format image to be verified
+ * @verify: data CRC verification flag
+ *
+ * image_get_kernel() verifies legacy image integrity and returns pointer to
+ * legacy image header if image verification was completed successfully.
+ *
+ * returns:
+ *     pointer to a legacy image header if valid image was found
+ *     otherwise return NULL
+ */
+static image_header_t *image_get_kernel(ulong img_addr, int verify)
+{
+	image_header_t *hdr = (image_header_t *)img_addr;
+
+	if (!image_check_magic(hdr)) {
+		puts("Bad Magic Number\n");
+		bootstage_error(BOOTSTAGE_ID_CHECK_MAGIC);
+		return NULL;
+	}
+	bootstage_mark(BOOTSTAGE_ID_CHECK_HEADER);
+
+	if (!image_check_hcrc(hdr)) {
+		puts("Bad Header Checksum\n");
+		bootstage_error(BOOTSTAGE_ID_CHECK_HEADER);
+		return NULL;
+	}
+
+	bootstage_mark(BOOTSTAGE_ID_CHECK_CHECKSUM);
+	image_print_contents(hdr);
+
+	if (verify) {
+		puts("   Verifying Checksum ... ");
+		if (!image_check_dcrc(hdr)) {
+			printf("Bad Data CRC\n");
+			bootstage_error(BOOTSTAGE_ID_CHECK_CHECKSUM);
+			return NULL;
+		}
+		puts("OK\n");
+	}
+	bootstage_mark(BOOTSTAGE_ID_CHECK_ARCH);
+
+	if (!image_check_target_arch(hdr)) {
+		printf("Unsupported Architecture 0x%x\n", image_get_arch(hdr));
+		bootstage_error(BOOTSTAGE_ID_CHECK_ARCH);
+		return NULL;
+	}
+	return hdr;
+}
+#endif
+
+/**
+ * boot_get_kernel - find kernel image
+ * @os_data: pointer to a ulong variable, will hold os data start address
+ * @os_len: pointer to a ulong variable, will hold os data length
+ *
+ * boot_get_kernel() tries to find a kernel image, verifies its integrity
+ * and locates kernel data.
+ *
+ * returns:
+ *     pointer to image header if valid image was found, plus kernel start
+ *     address and length, otherwise NULL
+ */
+static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
+				   char * const argv[], bootm_headers_t *images,
+				   ulong *os_data, ulong *os_len)
+{
+#if defined(CONFIG_IMAGE_FORMAT_LEGACY)
+	image_header_t	*hdr;
+#endif
+	ulong		img_addr;
+	const void *buf;
+#if defined(CONFIG_FIT)
+	const char	*fit_uname_config = NULL;
+	const char	*fit_uname_kernel = NULL;
+	int		os_noffset;
+#endif
+
+	/* find out kernel image address */
+	if (argc < 1) {
+		img_addr = load_addr;
+		debug("*  kernel: default image load address = 0x%08lx\n",
+		      load_addr);
+#if defined(CONFIG_FIT)
+	} else if (fit_parse_conf(argv[0], load_addr, &img_addr,
+				  &fit_uname_config)) {
+		debug("*  kernel: config '%s' from image at 0x%08lx\n",
+		      fit_uname_config, img_addr);
+	} else if (fit_parse_subimage(argv[0], load_addr, &img_addr,
+				     &fit_uname_kernel)) {
+		debug("*  kernel: subimage '%s' from image at 0x%08lx\n",
+		      fit_uname_kernel, img_addr);
+#endif
+	} else {
+		img_addr = simple_strtoul(argv[0], NULL, 16);
+		debug("*  kernel: cmdline image address = 0x%08lx\n",
+		      img_addr);
+	}
+
+	bootstage_mark(BOOTSTAGE_ID_CHECK_MAGIC);
+
+	/* copy from dataflash if needed */
+	img_addr = genimg_get_image(img_addr);
+
+	/* check image type, for FIT images get FIT kernel node */
+	*os_data = *os_len = 0;
+	buf = map_sysmem(img_addr, 0);
+	switch (genimg_get_format(buf)) {
+#if defined(CONFIG_IMAGE_FORMAT_LEGACY)
+	case IMAGE_FORMAT_LEGACY:
+		printf("## Booting kernel from Legacy Image at %08lx ...\n",
+		       img_addr);
+		hdr = image_get_kernel(img_addr, images->verify);
+		if (!hdr)
+			return NULL;
+		bootstage_mark(BOOTSTAGE_ID_CHECK_IMAGETYPE);
+
+		/* get os_data and os_len */
+		switch (image_get_type(hdr)) {
+		case IH_TYPE_KERNEL:
+		case IH_TYPE_KERNEL_NOLOAD:
+			*os_data = image_get_data(hdr);
+			*os_len = image_get_data_size(hdr);
+			break;
+		case IH_TYPE_MULTI:
+			image_multi_getimg(hdr, 0, os_data, os_len);
+			break;
+		case IH_TYPE_STANDALONE:
+			*os_data = image_get_data(hdr);
+			*os_len = image_get_data_size(hdr);
+			break;
+		default:
+			printf("Wrong Image Type for %s command\n",
+			       cmdtp->name);
+			bootstage_error(BOOTSTAGE_ID_CHECK_IMAGETYPE);
+			return NULL;
+		}
+
+		/*
+		 * copy image header to allow for image overwrites during
+		 * kernel decompression.
+		 */
+		memmove(&images->legacy_hdr_os_copy, hdr,
+			sizeof(image_header_t));
+
+		/* save pointer to image header */
+		images->legacy_hdr_os = hdr;
+
+		images->legacy_hdr_valid = 1;
+		bootstage_mark(BOOTSTAGE_ID_DECOMP_IMAGE);
+		break;
+#endif
+#if defined(CONFIG_FIT)
+	case IMAGE_FORMAT_FIT:
+		os_noffset = fit_image_load(images, FIT_KERNEL_PROP,
+				img_addr,
+				&fit_uname_kernel, &fit_uname_config,
+				IH_ARCH_DEFAULT, IH_TYPE_KERNEL,
+				BOOTSTAGE_ID_FIT_KERNEL_START,
+				FIT_LOAD_IGNORED, os_data, os_len);
+		if (os_noffset < 0)
+			return NULL;
+
+		images->fit_hdr_os = map_sysmem(img_addr, 0);
+		images->fit_uname_os = fit_uname_kernel;
+		images->fit_uname_cfg = fit_uname_config;
+		images->fit_noffset_os = os_noffset;
+		break;
+#endif
+#ifdef CONFIG_ANDROID_BOOT_IMAGE
+	case IMAGE_FORMAT_ANDROID:
+		printf("## Booting Android Image at 0x%08lx ...\n", img_addr);
+		if (android_image_get_kernel((void *)img_addr, images->verify,
+					     os_data, os_len))
+			return NULL;
+		break;
+#endif
+	default:
+		printf("Wrong Image Format for %s command\n", cmdtp->name);
+		bootstage_error(BOOTSTAGE_ID_FIT_KERNEL_INFO);
+		return NULL;
+	}
+
+	debug("   kernel data at 0x%08lx, len = 0x%08lx (%ld)\n",
+	      *os_data, *os_len, *os_len);
+
+	return buf;
+}