diff options
| -rw-r--r-- | src/commonlib/bsd/lz4_wrapper.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/src/commonlib/bsd/lz4_wrapper.c b/src/commonlib/bsd/lz4_wrapper.c index efe246bd02..566c2bf727 100644 --- a/src/commonlib/bsd/lz4_wrapper.c +++ b/src/commonlib/bsd/lz4_wrapper.c @@ -5,15 +5,29 @@ #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 endianness and allows some basic assumptions (such as unaligned - * access support), we can easily write the ones we need ourselves. */ +#include <endian.h> + +/* + * RISC-V and older ARM architectures do not mandate support for misaligned access. + * Our le16toh and friends functions assume misaligned access support. Writing the access + * like this causes the compiler to generate instructions using misaligned access (or not) + * depending on the architecture. So there is no performance penalty for platforms supporting + * misaligned access. + */ static uint16_t LZ4_readLE16(const void *src) { - return le16toh(*(const uint16_t *)src); + return *((const uint8_t *)src + 1) << 8 + | *(const uint8_t *)src; } + +static uint32_t LZ4_readLE32(const void *src) +{ + return *((const uint8_t *)src + 3) << 24 + | *((const uint8_t *)src + 2) << 16 + | *((const uint8_t *)src + 1) << 8 + | *(const uint8_t *)src; +} + static void LZ4_copy8(void *dst, const void *src) { /* ARM32 needs to be a special snowflake to prevent GCC from coalescing the @@ -107,7 +121,7 @@ size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn) return 0; /* input overrun */ /* We assume there's always only a single, standard frame. */ - if (le32toh(h->magic) != LZ4F_MAGICNUMBER + if (LZ4_readLE32(&h->magic) != LZ4F_MAGICNUMBER || (h->flags & VERSION) != (1 << VERSION_SHIFT)) return 0; /* unknown format */ if ((h->flags & RESERVED0) || (h->block_descriptor & RESERVED1_2)) @@ -127,7 +141,7 @@ size_t ulz4fn(const void *src, size_t srcn, void *dst, size_t dstn) break; /* input overrun */ struct lz4_block_header b = { - .raw = le32toh(*(const uint32_t *)in) + .raw = LZ4_readLE32((const uint32_t *)in) }; in += sizeof(struct lz4_block_header); |