diff options
| -rw-r--r-- | src/arch/x86/ebda.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/src/arch/x86/ebda.c b/src/arch/x86/ebda.c index 284b5be1b5..b5dfb413ae 100644 --- a/src/arch/x86/ebda.c +++ b/src/arch/x86/ebda.c @@ -22,6 +22,10 @@ void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size) { + u16 low_memory_kb; + u16 ebda_kb; + void *ebda; + /* Skip in S3 resume path */ if (acpi_is_wakeup_s3()) return; @@ -29,15 +33,20 @@ void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size) if (!low_memory_size || !ebda_segment || !ebda_size) return; + low_memory_kb = low_memory_size >> 10; + ebda_kb = ebda_size >> 10; + ebda = (void *)((uintptr_t)ebda_segment << 4); + /* clear BIOS DATA AREA */ - memset((void *)X86_BDA_BASE, 0, X86_BDA_SIZE); + memset(X86_BDA_BASE, 0, X86_BDA_SIZE); - write16(X86_EBDA_LOWMEM, (low_memory_size >> 10)); - write16(X86_EBDA_SEGMENT, ebda_segment); + /* Avoid unaligned write16() since it's undefined behavior */ + memcpy(X86_EBDA_LOWMEM, &low_memory_kb, sizeof(low_memory_kb)); + memcpy(X86_EBDA_SEGMENT, &ebda_segment, sizeof(ebda_segment)); /* Set up EBDA */ - memset((void *)((uintptr_t)ebda_segment << 4), 0, ebda_size); - write16((void *)((uintptr_t)ebda_segment << 4), (ebda_size >> 10)); + memset(ebda, 0, ebda_size); + memcpy(ebda, &ebda_kb, sizeof(ebda_kb)); } void setup_default_ebda(void) |