diff options
Diffstat (limited to 'src/commonlib/bsd/lz4_wrapper.c')
| -rw-r--r-- | src/commonlib/bsd/lz4_wrapper.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/commonlib/bsd/lz4_wrapper.c b/src/commonlib/bsd/lz4_wrapper.c new file mode 100644 index 0000000000..2367afceaf --- /dev/null +++ b/src/commonlib/bsd/lz4_wrapper.c @@ -0,0 +1,174 @@ +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only */ + +#include <commonlib/bsd/compression.h> +#include <commonlib/bsd/helpers.h> +#include <endian.h> +#include <stdint.h> +#include <string.h> + +/* LZ4 comes with its own supposedly portable memory access functions, but they + * seem to be very inefficient in practice (at least on ARM64). Since coreboot + * knows about endinaness and allows some basic assumptions (such as unaligned + * access support), we can easily write the ones we need ourselves. */ +static uint16_t LZ4_readLE16(const void *src) +{ + return le16toh(*(const uint16_t *)src); +} +static void LZ4_copy8(void *dst, const void *src) +{ +/* ARM32 needs to be a special snowflake to prevent GCC from coalescing the + * access into LDRD/STRD (which don't support unaligned accesses). */ +#ifdef __arm__ /* ARMv < 6 doesn't support unaligned accesses at all. */ + #if defined(__COREBOOT_ARM_ARCH__) && __COREBOOT_ARM_ARCH__ < 6 + int i; + for (i = 0; i < 8; i++) + ((uint8_t *)dst)[i] = ((uint8_t *)src)[i]; + #else + uint32_t x0, x1; + __asm__ ("ldr %[x0], [%[src]]" + : [x0]"=r"(x0) + : [src]"r"(src), "m"(*(const uint32_t *)src)); + __asm__ ("ldr %[x1], [%[src], #4]" + : [x1]"=r"(x1) + : [src]"r"(src), "m"(*(const uint32_t *)(src + 4))); + __asm__ ("str %[x0], [%[dst]]" + : "=m"(*(uint32_t *)dst) + : [x0]"r"(x0), [dst]"r"(dst)); + __asm__ ("str %[x1], [%[dst], #4]" + : "=m"(*(uint32_t *)(dst + 4)) + : [x1]"r"(x1), [dst]"r"(dst)); + #endif +#elif defined(__riscv) + /* RISC-V implementations may trap on any unaligned access. */ + int i; + for (i = 0; i < 8; i++) + ((uint8_t *)dst)[i] = ((uint8_t *)src)[i]; +#else + *(uint64_t *)dst = *(const uint64_t *)src; +#endif +} + +typedef uint8_t BYTE; +typedef uint16_t U16; +typedef uint32_t U32; +typedef int32_t S32; +typedef uint64_t U64; + +#define FORCE_INLINE static __always_inline +#define likely(expr) __builtin_expect((expr) != 0, 1) +#define unlikely(expr) __builtin_expect((expr) != 0, 0) + +/* Unaltered (just removed unrelated code) from github.com/Cyan4973/lz4/dev. */ +#include "lz4.c.inc" /* #include for inlining, do not link! */ + +#define LZ4F_MAGICNUMBER 0x184D2204 + +struct lz4_frame_header { + uint32_t magic; + union { + uint8_t flags; + struct { + uint8_t reserved0 : 2; + uint8_t has_content_checksum : 1; + uint8_t has_content_size : 1; + uint8_t has_block_checksum : 1; + uint8_t independent_blocks : 1; + uint8_t version : 2; + }; + }; + union { + uint8_t block_descriptor; + struct { + uint8_t reserved1 : 4; + uint8_t max_block_size : 3; + uint8_t reserved2 : 1; + }; + }; + /* + uint64_t content_size iff has_content_size is set */ + /* + uint8_t header_checksum */ +} __packed; + +struct lz4_block_header { + union { + uint32_t raw; + struct { + uint32_t size : 31; + uint32_t not_compressed : 1; + }; + }; + /* + size bytes of data */ + /* + uint32_t block_checksum iff has_block_checksum is set */ +} __packed; + +size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn) +{ + const void *in = src; + void *out = dst; + size_t out_size = 0; + int has_block_checksum; + + { /* With in-place decompression the header may become invalid later. */ + const struct lz4_frame_header *h = in; + + if (srcn < sizeof(*h) + sizeof(uint64_t) + sizeof(uint8_t)) + return 0; /* input overrun */ + + /* We assume there's always only a single, standard frame. */ + if (le32toh(h->magic) != LZ4F_MAGICNUMBER || h->version != 1) + return 0; /* unknown format */ + if (h->reserved0 || h->reserved1 || h->reserved2) + return 0; /* reserved must be zero */ + if (!h->independent_blocks) + return 0; /* we don't support block dependency */ + has_block_checksum = h->has_block_checksum; + + in += sizeof(*h); + if (h->has_content_size) + in += sizeof(uint64_t); + in += sizeof(uint8_t); + } + + while (1) { + struct lz4_block_header b = { + { .raw = le32toh(*(const uint32_t *)in) } + }; + in += sizeof(struct lz4_block_header); + + if ((size_t)(in - src) + b.size > srcn) + break; /* input overrun */ + + if (!b.size) { + out_size = out - dst; + break; /* decompression successful */ + } + + if (b.not_compressed) { + size_t size = MIN((uintptr_t)b.size, (uintptr_t)dst + + dstn - (uintptr_t)out); + memcpy(out, in, size); + if (size < b.size) + break; /* output overrun */ + out += size; + } else { + /* constant folding essential, do not touch params! */ + int ret = LZ4_decompress_generic(in, out, b.size, + dst + dstn - out, endOnInputSize, + full, 0, noDict, out, NULL, 0); + if (ret < 0) + break; /* decompression error */ + out += ret; + } + + in += b.size; + if (has_block_checksum) + in += sizeof(uint32_t); + } + + return out_size; +} + +size_t ulz4f(const void *src, void *dst) +{ + /* LZ4 uses signed size parameters, so can't just use ((u32)-1) here. */ + return ulz4fn(src, 1*GiB, dst, 1*GiB); +} |