common/spl/spl_fit.c

/*
 * Copyright (C) 2016 Google, Inc
 * Written by Simon Glass <sjg@chromium.org>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <errno.h>
#include <image.h>
#include <libfdt.h>
#include <spl.h>

static ulong fdt_getprop_u32(const void *fdt, int node, const char *prop)
{
	const u32 *cell;
	int len;

	cell = fdt_getprop(fdt, node, prop, &len);
	if (len != sizeof(*cell))
		return -1U;
	return fdt32_to_cpu(*cell);
}

/*
 * Iterate over all /configurations subnodes and call a platform specific
 * function to find the matching configuration.
 * Returns the node offset or a negative error number.
 */
static int spl_fit_find_config_node(const void *fdt)
{
	const char *name;
	int conf, node, len;

	conf = fdt_path_offset(fdt, FIT_CONFS_PATH);
	if (conf < 0) {
		debug("%s: Cannot find /configurations node: %d\n", __func__,
		      conf);
		return -EINVAL;
	}
	for (node = fdt_first_subnode(fdt, conf);
	     node >= 0;
	     node = fdt_next_subnode(fdt, node)) {
		name = fdt_getprop(fdt, node, "description", &len);
		if (!name) {
#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
			printf("%s: Missing FDT description in DTB\n",
			       __func__);
#endif
			return -EINVAL;
		}
		if (board_fit_config_name_match(name))
			continue;

		debug("Selecting config '%s'", name);

		return node;
	}

	return -ENOENT;
}

/**
 * spl_fit_get_image_node(): By using the matching configuration subnode,
 * retrieve the name of an image, specified by a property name and an index
 * into that.
 * @fit:	Pointer to the FDT blob.
 * @images:	Offset of the /images subnode.
 * @type:	Name of the property within the configuration subnode.
 * @index:	Index into the list of strings in this property.
 *
 * Return:	the node offset of the respective image node or a negative
 * 		error number.
 */
static int spl_fit_get_image_node(const void *fit, int images,
				  const char *type, int index)
{
	const char *name, *str;
	int node, conf_node;
	int len, i;

	conf_node = spl_fit_find_config_node(fit);
	if (conf_node < 0) {
#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
		printf("No matching DT out of these options:\n");
		for (node = fdt_first_subnode(fit, conf_node);
		     node >= 0;
		     node = fdt_next_subnode(fit, node)) {
			name = fdt_getprop(fit, node, "description", &len);
			printf("   %s\n", name);
		}
#endif
		return conf_node;
	}

	name = fdt_getprop(fit, conf_node, type, &len);
	if (!name) {
		debug("cannot find property '%s': %d\n", type, len);
		return -EINVAL;
	}

	str = name;
	for (i = 0; i < index; i++) {
		str = strchr(str, '\0') + 1;
		if (!str || (str - name >= len)) {
			debug("no string for index %d\n", index);
			return -E2BIG;
		}
	}

	debug("%s: '%s'\n", type, str);
	node = fdt_subnode_offset(fit, images, str);
	if (node < 0) {
		debug("cannot find image node '%s': %d\n", str, node);
		return -EINVAL;
	}

	return node;
}

static int get_aligned_image_offset(struct spl_load_info *info, int offset)
{
	/*
	 * If it is a FS read, get the first address before offset which is
	 * aligned to ARCH_DMA_MINALIGN. If it is raw read return the
	 * block number to which offset belongs.
	 */
	if (info->filename)
		return offset & ~(ARCH_DMA_MINALIGN - 1);

	return offset / info->bl_len;
}

static int get_aligned_image_overhead(struct spl_load_info *info, int offset)
{
	/*
	 * If it is a FS read, get the difference between the offset and
	 * the first address before offset which is aligned to
	 * ARCH_DMA_MINALIGN. If it is raw read return the offset within the
	 * block.
	 */
	if (info->filename)
		return offset & (ARCH_DMA_MINALIGN - 1);

	return offset % info->bl_len;
}

static int get_aligned_image_size(struct spl_load_info *info, int data_size,
				  int offset)
{
	data_size = data_size + get_aligned_image_overhead(info, offset);

	if (info->filename)
		return data_size;

	return (data_size + info->bl_len - 1) / info->bl_len;
}

int spl_load_simple_fit(struct spl_image_info *spl_image,
			struct spl_load_info *info, ulong sector, void *fit)
{
	int sectors;
	ulong size, load;
	unsigned long count;
	int node, images;
	void *load_ptr;
	int fdt_offset, fdt_len;
	int data_offset, data_size;
	int base_offset, align_len = ARCH_DMA_MINALIGN - 1;
	int src_sector;
	void *dst, *src;

	/*
	 * Figure out where the external images start. This is the base for the
	 * data-offset properties in each image.
	 */
	size = fdt_totalsize(fit);
	size = (size + 3) & ~3;
	base_offset = (size + 3) & ~3;

	/*
	 * So far we only have one block of data from the FIT. Read the entire
	 * thing, including that first block, placing it so it finishes before
	 * where we will load the image.
	 *
	 * Note that we will load the image such that its first byte will be
	 * at the load address. Since that byte may be part-way through a
	 * block, we may load the image up to one block before the load
	 * address. So take account of that here by subtracting an addition
	 * block length from the FIT start position.
	 *
	 * In fact the FIT has its own load address, but we assume it cannot
	 * be before CONFIG_SYS_TEXT_BASE.
	 */
	fit = (void *)((CONFIG_SYS_TEXT_BASE - size - info->bl_len -
			align_len) & ~align_len);
	sectors = get_aligned_image_size(info, size, 0);
	count = info->read(info, sector, sectors, fit);
	debug("fit read sector %lx, sectors=%d, dst=%p, count=%lu\n",
	      sector, sectors, fit, count);
	if (count == 0)
		return -EIO;

	/* find the node holding the images information */
	images = fdt_path_offset(fit, FIT_IMAGES_PATH);
	if (images < 0) {
		debug("%s: Cannot find /images node: %d\n", __func__, images);
		return -1;
	}

	/* find the U-Boot image */
	node = spl_fit_get_image_node(fit, images, "firmware", 0);
	if (node < 0) {
		debug("could not find firmware image, trying loadables...\n");
		node = spl_fit_get_image_node(fit, images, "loadables", 0);
	}
	if (node < 0) {
		debug("%s: Cannot find u-boot image node: %d\n",
		      __func__, node);
		return -1;
	}

	/* Get its information and set up the spl_image structure */
	data_offset = fdt_getprop_u32(fit, node, "data-offset");
	data_size = fdt_getprop_u32(fit, node, "data-size");
	load = fdt_getprop_u32(fit, node, "load");
	debug("data_offset=%x, data_size=%x\n", data_offset, data_size);
	spl_image->load_addr = load;
	spl_image->entry_point = load;
	spl_image->os = IH_OS_U_BOOT;

	/*
	 * Work out where to place the image. We read it so that the first
	 * byte will be at 'load'. This may mean we need to load it starting
	 * before then, since we can only read whole blocks.
	 */
	data_offset += base_offset;
	sectors = get_aligned_image_size(info, data_size, data_offset);
	load_ptr = (void *)load;
	debug("U-Boot size %x, data %p\n", data_size, load_ptr);
	dst = load_ptr;

	/* Read the image */
	src_sector = sector + get_aligned_image_offset(info, data_offset);
	debug("Aligned image read: dst=%p, src_sector=%x, sectors=%x\n",
	      dst, src_sector, sectors);
	count = info->read(info, src_sector, sectors, dst);
	if (count != sectors)
		return -EIO;
	debug("image: dst=%p, data_offset=%x, size=%x\n", dst, data_offset,
	      data_size);
	src = dst + get_aligned_image_overhead(info, data_offset);

#ifdef CONFIG_SPL_FIT_IMAGE_POST_PROCESS
	board_fit_image_post_process((void **)&src, (size_t *)&data_size);
#endif

	memcpy(dst, src, data_size);

	/* Figure out which device tree the board wants to use */
	node = spl_fit_get_image_node(fit, images, FIT_FDT_PROP, 0);
	if (node < 0) {
		debug("%s: cannot find FDT node\n", __func__);
		return node;
	}
	fdt_offset = fdt_getprop_u32(fit, node, "data-offset");
	fdt_len = fdt_getprop_u32(fit, node, "data-size");

	/*
	 * Read the device tree and place it after the image. There may be
	 * some extra data before it since we can only read entire blocks.
	 * And also align the destination address to ARCH_DMA_MINALIGN.
	 */
	dst = (void *)((load + data_size + align_len) & ~align_len);
	fdt_offset += base_offset;
	sectors = get_aligned_image_size(info, fdt_len, fdt_offset);
	src_sector = sector + get_aligned_image_offset(info, fdt_offset);
	count = info->read(info, src_sector, sectors, dst);
	debug("Aligned fdt read: dst %p, src_sector = %x, sectors %x\n",
	      dst, src_sector, sectors);
	if (count != sectors)
		return -EIO;

	/*
	 * Copy the device tree so that it starts immediately after the image.
	 * After this we will have the U-Boot image and its device tree ready
	 * for us to start.
	 */
	debug("fdt: dst=%p, data_offset=%x, size=%x\n", dst, fdt_offset,
	      fdt_len);
	src = dst + get_aligned_image_overhead(info, fdt_offset);
	dst = load_ptr + data_size;

#ifdef CONFIG_SPL_FIT_IMAGE_POST_PROCESS
	board_fit_image_post_process((void **)&src, (size_t *)&fdt_len);
#endif

	memcpy(dst, src, fdt_len);

	return 0;
}