3 files changed, 86 insertions, 0 deletions
diff --git a/src/arch/x86/include/arch/ebda.h b/src/arch/x86/include/arch/ebda.h
new file mode 100644
index 0000000000..1de609799d
--- /dev/null
+++ b/src/arch/x86/include/arch/ebda.h
@@ -0,0 +1,37 @@
+/*
+ * 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., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#ifndef __ARCH_EBDA_H
+#define __ARCH_EBDA_H
+
+#define X86_BDA_SIZE		0x200
+#define X86_BDA_BASE		0x400
+#define X86_EBDA_SEGMENT	0x40e
+#define X86_EBDA_LOWMEM		0x413
+
+#define DEFAULT_EBDA_LOWMEM	(1024 << 10)
+#define DEFAULT_EBDA_SEGMENT	0xF600
+#define DEFAULT_EBDA_SIZE	0x400
+
+void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size);
+void setup_default_ebda(void);
+
+#endif
diff --git a/src/arch/x86/lib/Makefile.inc b/src/arch/x86/lib/Makefile.inc
index 96fb9b07f5..8f5fd5f1eb 100644
--- a/src/arch/x86/lib/Makefile.inc
+++ b/src/arch/x86/lib/Makefile.inc
@@ -8,6 +8,7 @@ ramstage-y += exception.c
 ramstage-$(CONFIG_IOAPIC) += ioapic.c
 ramstage-y += memset.c
 ramstage-y += memcpy.c
+ramstage-y += ebda.c
 
 romstage-y += romstage_console.c
 romstage-y += cbfs_and_run.c
diff --git a/src/arch/x86/lib/ebda.c b/src/arch/x86/lib/ebda.c
new file mode 100644
index 0000000000..faf1451a2f
--- /dev/null
+++ b/src/arch/x86/lib/ebda.c
@@ -0,0 +1,48 @@
+/*
+ * 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., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <arch/io.h>
+#include <arch/ebda.h>
+
+void setup_ebda(u32 low_memory_size, u16 ebda_segment, u16 ebda_size)
+{
+	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 *)(ebda_segment << 4), 0, ebda_size);
+	write16((ebda_segment << 4), (ebda_size >> 10));
+}
+
+void setup_default_ebda(void)
+{
+	setup_ebda(DEFAULT_EBDA_LOWMEM,
+		   DEFAULT_EBDA_SEGMENT,
+		   DEFAULT_EBDA_SIZE);
+}