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Diffstat (limited to 'src/lib/cbfs_core.c')
-rw-r--r-- | src/lib/cbfs_core.c | 174 |
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; + } +} + |