diff options
author | Subrata Banik <subrata.banik@intel.com> | 2017-09-10 20:06:22 +0530 |
---|---|---|
committer | Aaron Durbin <adurbin@chromium.org> | 2017-09-22 15:29:38 +0000 |
commit | 19dbffd010af7713156ccfeecd019a6e8eedefaf (patch) | |
tree | a705aa97941bf4c6907a6dd1b8e34d7d65ed6060 /src | |
parent | c7590cd9f3ca6242dd05e2a35b16c256a8759087 (diff) | |
download | coreboot-19dbffd010af7713156ccfeecd019a6e8eedefaf.tar.xz |
arch/x86: Add ebda read/write functions into EBDA library
This patch provides new APIs to write into EBDA area
and read from EBDA area based on user input structure.
Change-Id: I26d5c0ba82c842f0b734a8e0f03abf148737c5c4
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/21536
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>
Diffstat (limited to 'src')
-rw-r--r-- | src/arch/x86/ebda.c | 59 | ||||
-rw-r--r-- | src/arch/x86/include/arch/ebda.h | 20 |
2 files changed, 78 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); diff --git a/src/arch/x86/include/arch/ebda.h b/src/arch/x86/include/arch/ebda.h index 428bc92c27..2347ea5318 100644 --- a/src/arch/x86/include/arch/ebda.h +++ b/src/arch/x86/include/arch/ebda.h @@ -32,4 +32,24 @@ void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size); void setup_default_ebda(void); +/* + * This read/write API only allows and assumes + * a single EBDA structure type for a platform. + */ + +/* + * 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); +/* + * 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); + #endif |