vbe: Support reading the next SPL phase via VBE

Add an SPL loader to obtain the next-phase binary from a FIT provided
by the VBE driver.

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

1 files changed, 196 insertions, 0 deletions

diff --git a/boot/vbe_simple_fw.c b/boot/vbe_simple_fw.c
new file mode 100644
index 0000000000..fc05e9e2bd
--- /dev/null
+++ b/boot/vbe_simple_fw.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Verified Boot for Embedded (VBE) loading firmware phases
+ *
+ * Copyright 2022 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY LOGC_BOOT
+
+#include <common.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <bootmeth.h>
+#include <bootstage.h>
+#include <dm.h>
+#include <image.h>
+#include <log.h>
+#include <mapmem.h>
+#include <memalign.h>
+#include <mmc.h>
+#include <spl.h>
+#include <vbe.h>
+#include <dm/device-internal.h>
+#include "vbe_simple.h"
+
+/**
+ * vbe_simple_read_bootflow_fw() - Create a bootflow for firmware
+ *
+ * Locates and loads the firmware image (FIT) needed for the next phase. The FIT
+ * should ideally use external data, to reduce the amount of it that needs to be
+ * read.
+ *
+ * @bdev: bootdev device containing the firmwre
+ * @meth: VBE simple bootmeth
+ * @blow: Place to put the created bootflow, on success
+ * @return 0 if OK, -ve on error
+ */
+int vbe_simple_read_bootflow_fw(struct udevice *dev, struct bootflow *bflow)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(u8, sbuf, MMC_MAX_BLOCK_LEN);
+	struct udevice *media = dev_get_parent(bflow->dev);
+	struct udevice *meth = bflow->method;
+	struct simple_priv *priv = dev_get_priv(meth);
+	const char *fit_uname, *fit_uname_config;
+	struct bootm_headers images = {};
+	ulong offset, size, blknum, addr, len, load_addr, num_blks;
+	enum image_phase_t phase;
+	struct blk_desc *desc;
+	struct udevice *blk;
+	int node, ret;
+	void *buf;
+
+	log_debug("media=%s\n", media->name);
+	ret = blk_get_from_parent(media, &blk);
+	if (ret)
+		return log_msg_ret("med", ret);
+	log_debug("blk=%s\n", blk->name);
+	desc = dev_get_uclass_plat(blk);
+
+	offset = priv->area_start + priv->skip_offset;
+
+	/* read in one block to find the FIT size */
+	blknum =  offset / desc->blksz;
+	log_debug("read at %lx, blknum %lx\n", 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 > priv->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 = (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);
+	}
+
+	/* set up the bootflow with the info we obtained */
+	bflow->name = strdup(fdt_get_name(buf, node, NULL));
+	if (!bflow->name)
+		return log_msg_ret("name", -ENOMEM);
+	bflow->blk = blk;
+	bflow->buf = map_sysmem(load_addr, len);
+	bflow->size = len;
+
+	return 0;
+}
+
+static int simple_load_from_image(struct spl_image_info *spl_image,
+				  struct spl_boot_device *bootdev)
+{
+	struct udevice *meth, *bdev;
+	struct simple_priv *priv;
+	struct bootflow bflow;
+	int ret;
+
+	if (spl_phase() != PHASE_VPL && spl_phase() != PHASE_SPL)
+		return -ENOENT;
+
+	vbe_find_first_device(&meth);
+	if (!meth)
+		return log_msg_ret("vd", -ENODEV);
+	log_debug("vbe dev %s\n", meth->name);
+	ret = device_probe(meth);
+	if (ret)
+		return log_msg_ret("probe", ret);
+
+	priv = dev_get_priv(meth);
+	log_debug("simple %s\n", priv->storage);
+	ret = bootdev_find_by_label(priv->storage, &bdev);
+	if (ret)
+		return log_msg_ret("bd", ret);
+	log_debug("bootdev %s\n", bdev->name);
+
+	bootflow_init(&bflow, bdev, meth);
+	ret = bootmeth_read_bootflow(meth, &bflow);
+	log_debug("\nfw ret=%d\n", ret);
+	if (ret)
+		return log_msg_ret("rd", ret);
+
+	/* jump to the image */
+	spl_image->flags = SPL_SANDBOXF_ARG_IS_BUF;
+	spl_image->arg = bflow.buf;
+	spl_image->size = bflow.size;
+	log_debug("Image: %s at %p size %x\n", bflow.name, bflow.buf,
+		  bflow.size);
+
+	/* this is not used from now on, so free it */
+	bootflow_free(&bflow);
+
+	return 0;
+}
+SPL_LOAD_IMAGE_METHOD("vbe_simple", 5, BOOT_DEVICE_VBE,
+		      simple_load_from_image);