/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only */ #include <commonlib/bsd/compression.h> #include <commonlib/bsd/helpers.h> #include <commonlib/bsd/sysincludes.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) { if ((size_t)(in - src) + sizeof(struct lz4_block_header) > srcn) break; /* input overrun */ 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); }