vbe: Split out reading a FIT into the common file

Loading a FIT is useful for other VBE methods, such as ABrec. Create a new function to handling reading it. Signed-off-by: Simon Glass <sjg@chromium.org>
2025-01-22 09:47:49 -06:00
parent 0a59dc4199
commit ea6cfc55e0
3 changed files with 139 additions and 90 deletions
@@ -6,7 +6,11 @@
 * Written by Simon Glass <sjg@chromium.org>
 */

+#include <bootstage.h>
+#include <dm.h>
 #include <blk.h>
+#include <image.h>
+#include <mapmem.h>
 #include <memalign.h>
 #include <spl.h>
 #include <u-boot/crc.h>
@@ -100,3 +104,106 @@ int vbe_read_nvdata(struct udevice *blk, ulong offset, ulong size, u8 *buf)

 	return 0;
 }
+
+int vbe_read_fit(struct udevice *blk, ulong area_offset, ulong area_size,
+		 ulong *load_addrp, ulong *lenp, char **namep)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(u8, sbuf, MMC_MAX_BLOCK_LEN);
+	ulong size, blknum, addr, len, load_addr, num_blks;
+	const char *fit_uname, *fit_uname_config;
+	struct bootm_headers images = {};
+	enum image_phase_t phase;
+	struct blk_desc *desc;
+	int node, ret;
+	void *buf;
+
+	desc = dev_get_uclass_plat(blk);
+
+	/* read in one block to find the FIT size */
+	blknum =  area_offset / desc->blksz;
+	log_debug("read at %lx, blknum %lx\n", area_offset, blknum);
+	ret = blk_read(blk, blknum, 1, sbuf);
+	if (ret < 0)
+		return log_msg_ret("rd", ret);
+
+	ret = fdt_check_header(sbuf);
+	if (ret < 0)
+		return log_msg_ret("fdt", -EINVAL);
+	size = fdt_totalsize(sbuf);
+	if (size > area_size)
+		return log_msg_ret("fdt", -E2BIG);
+	log_debug("FIT size %lx\n", size);
+
+	/*
+	 * Load the FIT into the SPL memory. This is typically a FIT with
+	 * external data, so this is quite small, perhaps a few KB.
+	 */
+	addr = CONFIG_VAL(TEXT_BASE);
+	buf = map_sysmem(addr, size);
+	num_blks = DIV_ROUND_UP(size, desc->blksz);
+	log_debug("read %lx, %lx blocks to %lx / %p\n", size, num_blks, addr,
+		  buf);
+	ret = blk_read(blk, blknum, num_blks, buf);
+	if (ret < 0)
+		return log_msg_ret("rd", ret);
+
+	/* figure out the phase to load */
+	phase = IS_ENABLED(CONFIG_VPL_BUILD) ? IH_PHASE_SPL : IH_PHASE_U_BOOT;
+
+	/*
+	 * Load the image from the FIT. We ignore any load-address information
+	 * so in practice this simply locates the image in the external-data
+	 * region and returns its address and size. Since we only loaded the FIT
+	 * itself, only a part of the image will be present, at best.
+	 */
+	fit_uname = NULL;
+	fit_uname_config = NULL;
+	log_debug("loading FIT\n");
+	ret = fit_image_load(&images, addr, &fit_uname, &fit_uname_config,
+			     IH_ARCH_SANDBOX, image_ph(phase, IH_TYPE_FIRMWARE),
+			     BOOTSTAGE_ID_FIT_SPL_START, FIT_LOAD_IGNORED,
+			     &load_addr, &len);
+	if (ret < 0)
+		return log_msg_ret("ld", ret);
+	node = ret;
+	log_debug("loaded to %lx\n", load_addr);
+
+	/* For FIT external data, read in the external data */
+	if (load_addr + len > addr + size) {
+		ulong base, full_size;
+		void *base_buf;
+
+		/* Find the start address to load from */
+		base = ALIGN_DOWN(load_addr, desc->blksz);
+
+		/*
+		 * Get the total number of bytes to load, taking care of
+		 * block alignment
+		 */
+		full_size = load_addr + len - base;
+
+		/*
+		 * Get the start block number, number of blocks and the address
+		 * to load to, then load the blocks
+		 */
+		blknum = (area_offset + base - addr) / desc->blksz;
+		num_blks = DIV_ROUND_UP(full_size, desc->blksz);
+		base_buf = map_sysmem(base, full_size);
+		ret = blk_read(blk, blknum, num_blks, base_buf);
+		log_debug("read %lx %lx, %lx blocks to %lx / %p: ret=%d\n",
+			  blknum, full_size, num_blks, base, base_buf, ret);
+		if (ret < 0)
+			return log_msg_ret("rd", ret);
+	}
+	if (load_addrp)
+		*load_addrp = load_addr;
+	if (lenp)
+		*lenp = len;
+	if (namep) {
+		*namep = strdup(fdt_get_name(buf, node, NULL));
+		if (!namep)
+			return log_msg_ret("nam", -ENOMEM);
+	}
+
+	return 0;
+}