diff options
Diffstat (limited to 'src/arch/x86/ebda.c')
-rw-r--r-- | src/arch/x86/ebda.c | 59 |
1 files changed, 58 insertions, 1 deletions
diff --git a/src/arch/x86/ebda.c b/src/arch/x86/ebda.c index c828aa4f76..ba02e50401 100644 --- a/src/arch/x86/ebda.c +++ b/src/arch/x86/ebda.c @@ -20,6 +20,63 @@ #include <arch/ebda.h> #include <arch/acpi.h> #include <commonlib/endian.h> +#include <console/console.h> + +static void *get_ebda_start(void) +{ + return (void *)((uintptr_t)DEFAULT_EBDA_SEGMENT << 4); +} + +static bool is_length_valid(size_t dlength) +{ + /* Check if input data length is > DEFAULT_EBDA_SIZE */ + if (dlength > DEFAULT_EBDA_SIZE) + return false; + + /* Valid data length */ + return true; +} + +/* + * EBDA area is representing a 1KB memory area just below + * the top of conventional memory (below 1MB) + */ + +/* + * write_ebda_data is a wrapper function to write into EBDA area + * + * data = data to be written into EBDA area + * length = input data size. + */ +void write_ebda_data(const void *data, size_t length) +{ + void *ebda; + + if (!is_length_valid(length)) + die("Input data length is > EBDA default size (1KiB)!"); + + ebda = get_ebda_start(); + + memcpy(ebda, data, length); +} + +/* + * read_ebda_data is a wrapper function to read from EBDA area + * + * data = data read from EBDA area based on input size + * length = read data size. + */ +void read_ebda_data(void *data, size_t length) +{ + void *ebda; + + if (!is_length_valid(length)) + die("Input data length is > EBDA default size (1KiB)!"); + + ebda = get_ebda_start(); + + memcpy(data, ebda, length); +} void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size) { @@ -36,7 +93,7 @@ void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size) low_memory_kb = low_memory_size >> 10; ebda_kb = ebda_size >> 10; - ebda = (void *)((uintptr_t)ebda_segment << 4); + ebda = get_ebda_start(); /* clear BIOS DATA AREA */ zero_n(X86_BDA_BASE, X86_BDA_SIZE); |