1 files changed, 91 insertions, 0 deletions
diff --git a/core/localboot.c b/core/localboot.c
new file mode 100644
index 00000000..0f4b5820
--- /dev/null
+++ b/core/localboot.c
@@ -0,0 +1,91 @@
+/* -----------------------------------------------------------------------
+ *
+ *   Copyright 1999-2008 H. Peter Anvin - 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, Inc., 51 Franklin St, Fifth Floor,
+ *   Boston MA 02110-1301, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * -----------------------------------------------------------------------
+ */
+#include <sys/cpu.h>
+#include <sys/io.h>
+#include <string.h>
+#include <core.h>
+#include <fs.h>
+#include <bios.h>
+#include <graphics.h>
+
+/*
+ * localboot.c
+ *
+ * Boot from a local disk, or invoke INT 18h.
+ */
+
+#define LOCALBOOT_MSG	"Booting from local disk..."
+
+#define retry_count	16
+
+extern void local_boot16(void);
+
+/*
+ * Boot a specified local disk.  AX specifies the BIOS disk number; or
+ * -1 in case we should execute INT 18h ("next device.")
+ */
+__export void local_boot(int16_t ax)
+{
+	com32sys_t ireg, oreg;
+	int i;
+
+	syslinux_force_text_mode();
+
+	writestr(LOCALBOOT_MSG);
+	crlf();
+	cleanup_hardware();
+
+	if (ax == -1) {
+		/* Hope this does the right thing */
+		__intcall(0x18, &zero_regs, NULL);
+
+		/* If we returned, oh boy... */
+		kaboom();
+	}
+
+	/*
+	 * Load boot sector from the specified BIOS device and jump to
+	 * it.
+	 */
+	ireg.edx.b[0] = ax & 0xff;
+	ireg.eax.w[0] = 0;	/* Reset drive */
+	__intcall(0x13, &ireg, NULL);
+
+	ireg.eax.w[0] = 0x0201;	/* Read one sector */
+	ireg.ecx.w[0] = 0x0001;	/* C/H/S = 0/0/1 (first sector) */
+	ireg.ebx.w[0] = OFFS(trackbuf);
+	ireg.es = SEG(trackbuf);
+
+	for (i = 0; i < retry_count; i++) {
+		__intcall(0x13, &ireg, &oreg);
+
+		if (!(oreg.eflags.l & EFLAGS_CF))
+			break;
+	}
+
+	if (i == retry_count)
+		kaboom();
+
+	cli();			/* Abandon hope, ye who enter here */
+	memcpy((void *)0x07C00, trackbuf, 512);
+
+	ireg.esi.w[0] = OFFS(trackbuf);
+	ireg.edi.w[0] = 0x07C00;
+	ireg.edx.w[0] = ax;
+	call16(local_boot16, &ireg, NULL);
+}
+
+void pm_local_boot(com32sys_t *regs)
+{
+	local_boot(regs->eax.w[0]);
+}