SeaBIOS is an open source implementation of a 16-bit x86 BIOS. It can run in an emulator or natively on x86 hardware with the use of coreboot. With SeaBIOS's help, we can boot some OSes that require 16-bit BIOS services like Windows/DOS.
As U-Boot, we have to manually create a table where SeaBIOS gets system information (eg: E820) from. The table unfortunately has to follow the coreboot table format as SeaBIOS currently supports booting as a coreboot payload.
Signed-off-by: Bin Meng bmeng.cn@gmail.com ---
arch/x86/Kconfig | 10 ++++++++++ arch/x86/include/asm/tables.h | 3 +++ arch/x86/lib/tables.c | 15 +++++++++++++++ 3 files changed, 28 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index a0bd344..5fad794 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -449,6 +449,16 @@ config I8042_KEYB config DM_KEYBOARD default y
+config SEABIOS + bool "Support booting SeaBIOS" + help + SeaBIOS is an open source implementation of a 16-bit X86 BIOS. + It can run in an emulator or natively on X86 hardware with the use + of coreboot/U-Boot. By turning on this option, U-Boot prepares + all the configuration tables that are necessary to boot SeaBIOS. + + Check http://www.seabios.org/SeaBIOS for details. + source "arch/x86/lib/efi/Kconfig"
endmenu diff --git a/arch/x86/include/asm/tables.h b/arch/x86/include/asm/tables.h index 9e6754f..ae9f0d0 100644 --- a/arch/x86/include/asm/tables.h +++ b/arch/x86/include/asm/tables.h @@ -16,6 +16,9 @@
#define ROM_TABLE_ALIGN 1024
+/* SeaBIOS expects coreboot tables at address range 0x0000-0x1000 */ +#define CB_TABLE_ADDR 0x800 + /** * table_compute_checksum() - Compute a table checksum * diff --git a/arch/x86/lib/tables.c b/arch/x86/lib/tables.c index eccef8a..a156f2c 100644 --- a/arch/x86/lib/tables.c +++ b/arch/x86/lib/tables.c @@ -10,6 +10,7 @@ #include <asm/smbios.h> #include <asm/tables.h> #include <asm/acpi_table.h> +#include <asm/coreboot_tables.h>
/** * Function prototype to write a specific configuration table @@ -67,22 +68,36 @@ void write_tables(void) { u32 rom_table_start = ROM_TABLE_ADDR; u32 rom_table_end; +#ifdef CONFIG_SEABIOS u32 high_table, table_size; + struct memory_area cfg_tables[ARRAY_SIZE(table_write_funcs) + 1]; +#endif int i;
for (i = 0; i < ARRAY_SIZE(table_write_funcs); i++) { rom_table_end = table_write_funcs[i](rom_table_start); rom_table_end = ALIGN(rom_table_end, ROM_TABLE_ALIGN);
+#ifdef CONFIG_SEABIOS table_size = rom_table_end - rom_table_start; high_table = (u32)memalign(ROM_TABLE_ALIGN, table_size); if (high_table) { memset((void *)high_table, 0, table_size); table_write_funcs[i](high_table); + + cfg_tables[i].start = high_table; + cfg_tables[i].size = table_size; } else { printf("%d: no memory for configuration tables\n", i); } +#endif
rom_table_start = rom_table_end; } + +#ifdef CONFIG_SEABIOS + /* make sure the last item is zero */ + cfg_tables[i].size = 0; + write_coreboot_table(CB_TABLE_ADDR, cfg_tables); +#endif }