split CBFS support into shared core and extended functions

The core is data structures and basic file finding capabilities,
while option ROM handling, and loading stages and payloads is
"extended".

The core is rewritten to be BSD-l (its header already was), so
can be copied to libpayload verbatim.
It's also more robust in finding files in corrupted images, eg.
after partial erase or update.

Change-Id: Ic6923debf8bdf3c67c75746d3b31f3addab3dd74
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/114
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 174 insertions, 0 deletions

diff --git a/src/lib/cbfs_core.c b/src/lib/cbfs_core.c
new file mode 100644
index 0000000000..52ba58ded7
--- /dev/null
+++ b/src/lib/cbfs_core.c
@@ -0,0 +1,174 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * Copyright (C) 2011 secunet Security Networks AG
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* The CBFS core requires a couple of #defines or functions to adapt it to the target environment:
+ *
+ * CBFS_CORE_WITH_LZMA (must be #define)
+ *      if defined, ulzma() must exist for decompression of data streams
+ *
+ * phys_to_virt(x), virt_to_phys(x)
+ *      translate physical addresses to virtual and vice versa
+ *      can be idempotent if no mapping is necessary.
+ *
+ * ERROR(x...)
+ *      print an error message x (in printf format)
+ *
+ * LOG(x...)
+ *      print a debug message x (in printf format)
+ *
+ * romstart()
+ *      returns the start address of the ROM image, or 0xffffffff if ROM is
+ *      top-aligned. This is a physical address.
+ *
+ * romend()
+ *      returns the highest address of the ROM image + 1, for use if
+ *      romstart() == 0xffffffff. This is a physical address.
+ */
+
+#include <cbfs_core.h>
+
+
+/* returns pointer to master header or 0xffffffff if not found */
+static struct cbfs_header *get_cbfs_header(void)
+{
+	struct cbfs_header *header;
+
+	/* find header */
+	if (romstart() == 0xffffffff) {
+		header = (struct cbfs_header*)phys_to_virt(*(uint32_t*)phys_to_virt(romend() + CBFS_HEADPTR_ADDR));
+	} else {
+		// FIXME: where's the master header on ARM (our current bottom-aligned platform)?
+		header = NULL;
+	}
+	if (CBFS_HEADER_MAGIC != ntohl(header->magic)) {
+		ERROR("Could not find valid CBFS master header at %p: %x vs %x.\n", header, CBFS_HEADER_MAGIC, ntohl(header->magic));
+		if (header->magic == 0xffffffff) {
+			ERROR("Maybe ROM is not mapped properly?\n");
+		}
+		return (void*)0xffffffff;
+	}
+	return header;
+}
+
+// by must be power-of-two
+#define CBFS_ALIGN(val, by) (typeof(val))((uint32_t)(val + by - 1) & (uint32_t)~(by - 1))
+#define CBFS_ALIGN_UP(val, by) CBFS_ALIGN(val + 1, by)
+
+/* public API starts here*/
+struct cbfs_file *cbfs_find(const char *name)
+{
+	struct cbfs_header *header = get_cbfs_header();
+	if (header == (void*)0xffffffff) return NULL;
+
+	LOG("Searching for %s\n", name);
+
+	void *data, *dataend, *origdata;
+	/* find first entry */
+	if (romstart() == 0xffffffff) {
+		data = (void*)phys_to_virt(romend()) - ntohl(header->romsize) + ntohl(header->offset);
+		dataend = (void*)phys_to_virt(romend());
+	} else {
+		data = (void*)phys_to_virt(romstart()) + ntohl(header->offset);
+		dataend = (void*)phys_to_virt(romstart()) + ntohl(header->romsize);
+	}
+
+	int align = ntohl(header->align);
+
+	origdata = data;
+	while ((data < (dataend - 1)) && (data >= origdata)) {
+		struct cbfs_file *file = data;
+		if (memcmp(CBFS_FILE_MAGIC, file->magic, strlen(CBFS_FILE_MAGIC)) != 0) {
+			// no file header found. corruption?
+			// proceed in aligned steps to resynchronize
+			LOG("No file header found at %p, searching for header\n", data);
+			data = phys_to_virt(CBFS_ALIGN_UP(virt_to_phys(data), align));
+			continue;
+		}
+		LOG("Check %s\n", CBFS_NAME(file));
+		if (strcmp(CBFS_NAME(file), name) == 0) {
+			return file;
+		}
+		void *olddata = data;
+		data = phys_to_virt(CBFS_ALIGN(virt_to_phys(data) + ntohl(file->len) + ntohl(file->offset), align));
+		if (olddata > data) {
+			LOG("Something is wrong here. File chain moved from %p to %p\n", olddata, data);
+			return NULL;
+		}
+	}
+	return NULL;
+}
+
+void *cbfs_get_file(const char *name)
+{
+	struct cbfs_file *file = cbfs_find(name);
+
+	if (file == NULL) {
+		ERROR("Could not find file '%s'.\n", name);
+		return NULL;
+	}
+
+	return (void*)CBFS_SUBHEADER(file);
+}
+
+void *cbfs_find_file(const char *name, int type)
+{
+	struct cbfs_file *file = cbfs_find(name);
+
+	if (file == NULL) {
+		ERROR("Could not find file '%s'.\n", name);
+		return NULL;
+	}
+
+	if (ntohl(file->type) != type) {
+		ERROR("File '%s' is of type %x, but we requested %x.\n", name, ntohl(file->type), type);
+		return NULL;
+	}
+
+	return (void*)CBFS_SUBHEADER(file);
+}
+
+int cbfs_decompress(int algo, void *src, void *dst, int len)
+{
+	switch (algo) {
+		case CBFS_COMPRESS_NONE:
+			memcpy(dst, src, len);
+			return 0;
+#ifdef CBFS_CORE_WITH_LZMA
+		case CBFS_COMPRESS_LZMA:
+			if (ulzma(src, dst) != 0) {
+				return 0;
+			}
+			return -1;
+#endif
+		default:
+			ERROR("tried to decompress %d bytes with algorithm #%x, but that algorithm id is unsupported.\n", len, algo);
+			return -1;
+	}
+}
+