Add core support for a bloblist to convey data from SPL

At present there is no standard way in U-Boot to pass information from SPL
to U-Boot proper. But sometimes SPL wants to convey information to U-Boot
that U-Boot cannot easily figure out. For example, if SPL sets up SDRAM
then it might want to pass the size of SDRAM, or the location of each
bank, to U-Boot proper.

Add a new 'bloblist' feature which provides this. A bloblist is set up in
the first phase of U-Boot that runs (i.e. TPL or SPL). The location of
this info may be in SRAM or CAR (x86 cache-as-RAM) or somewhere else.

Information placed in this region is preserved (with a checksum) through
TPL and SPL and ends up in U-Boot. At this point it is copied into SDRAM
so it can be used after relocation.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Andreas Dannenberg <dannenberg@ti.com>

common/Kconfig

@@ -750,4 +750,52 @@ config UPDATE_TFTP_MSEC_MAX
 
 endmenu
 
+menu "Blob list"
+
+config BLOBLIST
+	bool "Support for a bloblist"
+	help
+	  This enables support for a bloblist in U-Boot, which can be passed
+	  from TPL to SPL to U-Boot proper (and potentially to Linux). The
+	  blob list supports multiple binary blobs of data, each with a tag,
+	  so that different U-Boot components can store data which can survive
+	  through to the next stage of the boot.
+
+config SPL_BLOBLIST
+	bool "Support for a bloblist in SPL"
+	depends on BLOBLIST
+	default y if SPL
+	help
+	  This enables a bloblist in SPL. If this is the first part of U-Boot
+	  to run, then the bloblist is set up in SPL and passed to U-Boot
+	  proper. If TPL also has a bloblist, then SPL uses the one from there.
+
+config TPL_BLOBLIST
+	bool "Support for a bloblist in TPL"
+	depends on BLOBLIST
+	default y if TPL
+	help
+	  This enables a bloblist in TPL. The bloblist is set up in TPL and
+	  passed to SPL and U-Boot proper.
+
+config BLOBLIST_SIZE
+	hex "Size of bloblist"
+	depends on BLOBLIST
+	default 0x400
+	help
+	  Sets the size of the bloblist in bytes. This must include all
+	  overhead (alignment, bloblist header, record header). The bloblist
+	  is set up in the first part of U-Boot to run (TPL, SPL or U-Boot
+	  proper), and this sane bloblist is used for subsequent stages.
+
+config BLOBLIST_ADDR
+	hex "Address of bloblist"
+	depends on BLOBLIST
+	default 0xe000 if SANDBOX
+	help
+	  Sets the address of the bloblist, set up by the first part of U-Boot
+	  which runs. Subsequent U-Boot stages typically use the same address.
+
+endmenu
+
 source "common/spl/Kconfig"

common/Makefile

@@ -61,6 +61,7 @@ obj-$(CONFIG_CMDLINE) += cli_readline.o cli_simple.o
 endif # !CONFIG_SPL_BUILD
 
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTAGE) += bootstage.o
+obj-$(CONFIG_$(SPL_TPL_)BLOBLIST) += bloblist.o
 
 ifdef CONFIG_SPL_BUILD
 ifdef CONFIG_SPL_DFU_SUPPORT

common/bloblist.c

@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bloblist.h>
+#include <log.h>
+#include <mapmem.h>
+#include <spl.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct bloblist_rec *bloblist_first_blob(struct bloblist_hdr *hdr)
+{
+	if (hdr->alloced <= hdr->hdr_size)
+		return NULL;
+	return (struct bloblist_rec *)((void *)hdr + hdr->hdr_size);
+}
+
+struct bloblist_rec *bloblist_next_blob(struct bloblist_hdr *hdr,
+					struct bloblist_rec *rec)
+{
+	ulong offset;
+
+	offset = (void *)rec - (void *)hdr;
+	offset += rec->hdr_size + ALIGN(rec->size, BLOBLIST_ALIGN);
+	if (offset >= hdr->alloced)
+		return NULL;
+	return (struct bloblist_rec *)((void *)hdr + offset);
+}
+
+#define foreach_rec(_rec, _hdr) \
+	for (_rec = bloblist_first_blob(_hdr); \
+	     _rec; \
+	     _rec = bloblist_next_blob(_hdr, _rec))
+
+static struct bloblist_rec *bloblist_findrec(uint tag)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+	struct bloblist_rec *rec;
+
+	if (!hdr)
+		return NULL;
+
+	foreach_rec(rec, hdr) {
+		if (rec->tag == tag)
+			return rec;
+	}
+
+	return NULL;
+}
+
+static int bloblist_addrec(uint tag, int size, struct bloblist_rec **recp)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+	struct bloblist_rec *rec;
+	int new_alloced;
+
+	new_alloced = hdr->alloced + sizeof(*rec) +
+			ALIGN(size, BLOBLIST_ALIGN);
+	if (new_alloced >= hdr->size) {
+		log(LOGC_BLOBLIST, LOGL_ERR,
+		    "Failed to allocate %x bytes size=%x, need size>=%x\n",
+		    size, hdr->size, new_alloced);
+		return log_msg_ret("bloblist add", -ENOSPC);
+	}
+	rec = (void *)hdr + hdr->alloced;
+	hdr->alloced = new_alloced;
+
+	rec->tag = tag;
+	rec->hdr_size = sizeof(*rec);
+	rec->size = size;
+	rec->spare = 0;
+	*recp = rec;
+
+	return 0;
+}
+
+static int bloblist_ensurerec(uint tag, struct bloblist_rec **recp, int size)
+{
+	struct bloblist_rec *rec;
+
+	rec = bloblist_findrec(tag);
+	if (rec) {
+		if (size && size != rec->size)
+			return -ESPIPE;
+	} else {
+		int ret;
+
+		ret = bloblist_addrec(tag, size, &rec);
+		if (ret)
+			return ret;
+	}
+	*recp = rec;
+
+	return 0;
+}
+
+void *bloblist_find(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	rec = bloblist_findrec(tag);
+	if (!rec)
+		return NULL;
+	if (size && size != rec->size)
+		return NULL;
+
+	return (void *)rec + rec->hdr_size;
+}
+
+void *bloblist_add(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	if (bloblist_addrec(tag, size, &rec))
+		return NULL;
+
+	return rec + 1;
+}
+
+int bloblist_ensure_size(uint tag, int size, void **blobp)
+{
+	struct bloblist_rec *rec;
+	int ret;
+
+	ret = bloblist_ensurerec(tag, &rec, size);
+	if (ret)
+		return ret;
+	*blobp = (void *)rec + rec->hdr_size;
+
+	return 0;
+}
+
+void *bloblist_ensure(uint tag, int size)
+{
+	struct bloblist_rec *rec;
+
+	if (bloblist_ensurerec(tag, &rec, size))
+		return NULL;
+
+	return (void *)rec + rec->hdr_size;
+}
+
+static u32 bloblist_calc_chksum(struct bloblist_hdr *hdr)
+{
+	struct bloblist_rec *rec;
+	u32 chksum;
+
+	chksum = crc32(0, (unsigned char *)hdr,
+		       offsetof(struct bloblist_hdr, chksum));
+	foreach_rec(rec, hdr) {
+		chksum = crc32(chksum, (void *)rec, rec->hdr_size);
+		chksum = crc32(chksum, (void *)rec + rec->hdr_size, rec->size);
+	}
+
+	return chksum;
+}
+
+int bloblist_new(ulong addr, uint size, uint flags)
+{
+	struct bloblist_hdr *hdr;
+
+	if (size < sizeof(*hdr))
+		return log_ret(-ENOSPC);
+	if (addr & (BLOBLIST_ALIGN - 1))
+		return log_ret(-EFAULT);
+	hdr = map_sysmem(addr, size);
+	memset(hdr, '\0', sizeof(*hdr));
+	hdr->version = BLOBLIST_VERSION;
+	hdr->hdr_size = sizeof(*hdr);
+	hdr->flags = flags;
+	hdr->magic = BLOBLIST_MAGIC;
+	hdr->size = size;
+	hdr->alloced = hdr->hdr_size;
+	hdr->chksum = 0;
+	gd->bloblist = hdr;
+
+	return 0;
+}
+
+int bloblist_check(ulong addr, uint size)
+{
+	struct bloblist_hdr *hdr;
+	u32 chksum;
+
+	hdr = map_sysmem(addr, sizeof(*hdr));
+	if (hdr->magic != BLOBLIST_MAGIC)
+		return log_msg_ret("Bad magic", -ENOENT);
+	if (hdr->version != BLOBLIST_VERSION)
+		return log_msg_ret("Bad version", -EPROTONOSUPPORT);
+	if (size && hdr->size != size)
+		return log_msg_ret("Bad size", -EFBIG);
+	chksum = bloblist_calc_chksum(hdr);
+	if (hdr->chksum != chksum) {
+		log(LOGC_BLOBLIST, LOGL_ERR, "Checksum %x != %x\n", hdr->chksum,
+		    chksum);
+		return log_msg_ret("Bad checksum", -EIO);
+	}
+	gd->bloblist = hdr;
+
+	return 0;
+}
+
+int bloblist_finish(void)
+{
+	struct bloblist_hdr *hdr = gd->bloblist;
+
+	hdr->chksum = bloblist_calc_chksum(hdr);
+
+	return 0;
+}
+
+int bloblist_init(void)
+{
+	bool expected;
+	int ret = -ENOENT;
+
+	/**
+	 * Wed expect to find an existing bloblist in the first phase of U-Boot
+	 * that runs
+	 */
+	expected = !u_boot_first_phase();
+	if (expected)
+		ret = bloblist_check(CONFIG_BLOBLIST_ADDR,
+				     CONFIG_BLOBLIST_SIZE);
+	if (ret) {
+		log(LOGC_BLOBLIST, expected ? LOGL_WARNING : LOGL_DEBUG,
+		    "Existing bloblist not found: creating new bloblist\n");
+		ret = bloblist_new(CONFIG_BLOBLIST_ADDR, CONFIG_BLOBLIST_SIZE,
+				   0);
+	} else {
+		log(LOGC_BLOBLIST, LOGL_DEBUG, "Found existing bloblist\n");
+	}
+
+	return ret;
+}

include/bloblist.h

@@ -0,0 +1,195 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * This provides a standard way of passing information between boot phases
+ * (TPL -> SPL -> U-Boot proper.)
+ *
+ * A list of blobs of data, tagged with their owner. The list resides in memory
+ * and can be updated by SPL, U-Boot, etc.
+ *
+ * Copyright 2018 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#ifndef __BLOBLIST_H
+#define __BLOBLIST_H
+
+enum {
+	BLOBLIST_VERSION	= 0,
+	BLOBLIST_MAGIC		= 0xb00757a3,
+	BLOBLIST_ALIGN		= 16,
+};
+
+enum bloblist_tag_t {
+	BLOBLISTT_NONE = 0,
+
+	/* Vendor-specific tags are permitted here */
+	BLOBLISTT_EC_HOSTEVENT,		/* Chromium OS EC host-event mask */
+	BLOBLISTT_SPL_HANDOFF,		/* Hand-off info from SPL */
+	BLOBLISTT_VBOOT_CTX,		/* Chromium OS verified boot context */
+	BLOBLISTT_VBOOT_HANDOFF,	/* Chromium OS internal handoff info */
+};
+
+/**
+ * struct bloblist_hdr - header for the bloblist
+ *
+ * This is stored at the start of the bloblist which is always on a 16-byte
+ * boundary. Records follow this header. The bloblist normally stays in the
+ * same place in memory as SPL and U-Boot execute, but it can be safely moved
+ * around.
+ *
+ * None of the bloblist structures contain pointers but it is possible to put
+ * pointers inside a bloblist record if desired. This is not encouraged,
+ * since it can make part of the bloblist inaccessible if the pointer is
+ * no-longer valid. It is better to just store all the data inside a bloblist
+ * record.
+ *
+ * Each bloblist record is aligned to a 16-byte boundary and follows immediately
+ * from the last.
+ *
+ * @version: BLOBLIST_VERSION
+ * @hdr_size: Size of this header, normally sizeof(struct bloblist_hdr). The
+ *	first bloblist_rec starts at this offset from the start of the header
+ * @flags: Space for BLOBLISTF_... flags (none yet)
+ * @magic: BLOBLIST_MAGIC
+ * @size: Total size of all records (non-zero if valid) including this header.
+ *	The bloblist extends for this many bytes from the start of this header.
+ * @alloced: Total size allocated for this bloblist. When adding new records,
+ *	the bloblist can grow up to this size. This starts out as
+ *	sizeof(bloblist_hdr) since we need at least that much space to store a
+ *	valid bloblist
+ * @spare: Space space
+ * @chksum: CRC32 for the entire bloblist allocated area. Since any of the
+ *	blobs can be altered after being created, this checksum is only valid
+ *	when the bloblist is finalised before jumping to the next stage of boot.
+ *	Note: @chksum is last to make it easier to exclude it from the checksum
+ *	calculation.
+ */
+struct bloblist_hdr {
+	u32 version;
+	u32 hdr_size;
+	u32 flags;
+	u32 magic;
+
+	u32 size;
+	u32 alloced;
+	u32 spare;
+	u32 chksum;
+};
+
+/**
+ * struct bloblist_rec - record for the bloblist
+ *
+ * NOTE: Only exported for testing purposes. Do not use this struct.
+ *
+ * The bloblist contains a number of records each consisting of this record
+ * structure followed by the data contained. Each records is 16-byte aligned.
+ *
+ * @tag: Tag indicating what the record contains
+ * @hdr_size: Size of this header, normally sizeof(struct bloblist_rec). The
+ *	record's data starts at this offset from the start of the record
+ * @size: Size of record in bytes, excluding the header size. This does not
+ *	need to be aligned (e.g. 3 is OK).
+ * @spare: Spare space for other things
+ */
+struct bloblist_rec {
+	u32 tag;
+	u32 hdr_size;
+	u32 size;
+	u32 spare;
+};
+
+/**
+ * bloblist_find() - Find a blob
+ *
+ * Searches the bloblist and returns the blob with the matching tag
+ *
+ * @tag:	Tag to search for (enum bloblist_tag_t)
+ * @size:	Expected size of the blob
+ * @return pointer to blob if found, or NULL if not found, or a blob was found
+ *	but it is the wrong size
+ */
+void *bloblist_find(uint tag, int size);
+
+/**
+ * bloblist_add() - Add a new blob
+ *
+ * Add a new blob to the bloblist
+ *
+ * This should only be called if you konw there is no existing blob for a
+ * particular tag. It is typically safe to call in the first phase of U-Boot
+ * (e.g. TPL or SPL). After that, bloblist_ensure() should be used instead.
+ *
+ * @tag:	Tag to add (enum bloblist_tag_t)
+ * @size:	Size of the blob
+ * @return pointer to the newly added block, or NULL if there is not enough
+ *	space for the blob
+ */
+void *bloblist_add(uint tag, int size);
+
+/**
+ * bloblist_ensure_size() - Find or add a blob
+ *
+ * Find an existing blob, or add a new one if not found
+ *
+ * @tag:	Tag to add (enum bloblist_tag_t)
+ * @size:	Size of the blob
+ * @blobp:	Returns a pointer to blob on success
+ * @return 0 if OK, -ENOSPC if it is missing and could not be added due to lack
+ *	of space, or -ESPIPE it exists but has the wrong size
+ */
+int bloblist_ensure_size(uint tag, int size, void **blobp);
+
+/**
+ * bloblist_ensure() - Find or add a blob
+ *
+ * Find an existing blob, or add a new one if not found
+ *
+ * @tag:	Tag to add (enum bloblist_tag_t)
+ * @size:	Size of the blob
+ * @return pointer to blob, or NULL if it is missing and could not be added due
+ *	to lack of space, or it exists but has the wrong size
+ */
+void *bloblist_ensure(uint tag, int size);
+
+/**
+ * bloblist_new() - Create a new, empty bloblist of a given size
+ *
+ * @addr: Address of bloblist
+ * @size: Initial size for bloblist
+ * @flags: Flags to use for bloblist
+ * @return 0 if OK, -EFAULT if addr is not aligned correctly, -ENOSPC is the
+ *	area is not large enough
+ */
+int bloblist_new(ulong addr, uint size, uint flags);
+
+/**
+ * bloblist_check() - Check if a bloblist exists
+ *
+ * @addr: Address of bloblist
+ * @size: Expected size of blobsize, or 0 to detect the size
+ * @return 0 if OK, -ENOENT if the magic number doesn't match (indicating that
+ *	there problem is no bloblist at the given address), -EPROTONOSUPPORT
+ *	if the version does not match, -EIO if the checksum does not match,
+ *	-EFBIG if the expected size does not match the detected size
+ */
+int bloblist_check(ulong addr, uint size);
+
+/**
+ * bloblist_finish() - Set up the bloblist for the next U-Boot part
+ *
+ * This sets the correct checksum for the bloblist. This ensures that the
+ * bloblist will be detected correctly by the next phase of U-Boot.
+ *
+ * @return 0
+ */
+int bloblist_finish(void);
+
+/**
+ * bloblist_init() - Init the bloblist system with a single bloblist
+ *
+ * This uses CONFIG_BLOBLIST_ADDR and CONFIG_BLOBLIST_SIZE to set up a bloblist
+ * for use by U-Boot.
+ */
+int bloblist_init(void);
+
+#endif /* __BLOBLIST_H */

include/log.h

@@ -48,6 +48,7 @@ enum log_category_t {
 	LOGC_EFI,	/* EFI implementation */
 	LOGC_ALLOC,	/* Memory allocation */
 	LOGC_SANDBOX,	/* Related to the sandbox board */
+	LOGC_BLOBLIST,	/* Bloblist */
 
 	LOGC_COUNT,	/* Number of log categories */
 	LOGC_END,	/* Sentinel value for a list of log categories */