diff options
Diffstat (limited to 'src/arch/x86/ebda.c')
-rw-r--r-- | src/arch/x86/ebda.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/src/arch/x86/ebda.c b/src/arch/x86/ebda.c new file mode 100644 index 0000000000..47dfbdb1e9 --- /dev/null +++ b/src/arch/x86/ebda.c @@ -0,0 +1,52 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2012 The Chromium OS Authors. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; version 2 of + * the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc. + */ + +#include <stdint.h> +#include <string.h> +#include <arch/io.h> +#include <arch/ebda.h> +#include <arch/acpi.h> + +void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size) +{ + /* Skip in S3 resume path */ + if (acpi_is_wakeup_s3()) + return; + + if (!low_memory_size || !ebda_segment || !ebda_size) + return; + + /* clear BIOS DATA AREA */ + memset((void *)X86_BDA_BASE, 0, X86_BDA_SIZE); + + write16(X86_EBDA_LOWMEM, (low_memory_size >> 10)); + write16(X86_EBDA_SEGMENT, 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)); +} + +void setup_default_ebda(void) +{ + setup_ebda(DEFAULT_EBDA_LOWMEM, + DEFAULT_EBDA_SEGMENT, + DEFAULT_EBDA_SIZE); +} |