1 files changed, 73 insertions, 0 deletions
diff --git a/boot/include/bios.h b/boot/include/bios.h
new file mode 100644
index 0000000..a19e570
--- /dev/null
+++ b/boot/include/bios.h
@@ -0,0 +1,73 @@
+/*
+** @file	bios.h
+**
+** @author	Warren R. Carithers
+**
+** BIOS-related declarations
+*/
+
+#ifndef BIOS_H_
+#define BIOS_H_
+
+/*
+** BIOS-related memory addresses
+*/
+
+#define BIOS_BDA       0x0400
+
+/*
+** Selected BIOS interrupt numbers
+*/
+
+#define BIOS_TIMER     0x08
+#define BIOS_KBD       0x09
+#define BIOS_VIDEO     0x10
+#define BIOS_EQUIP     0x11
+#define BIOS_MSIZ      0x12
+#define BIOS_DISK      0x13
+#define BIOS_SERIAL    0x14
+#define BIOS_MISC      0x15
+#define BIOS_KBDSVC    0x16
+#define BIOS_PRTSVC    0x17
+#define BIOS_BOOT      0x19
+#define BIOS_RTCPCI    0x1a
+
+// BIOS video commands (AH)
+#define BV_W_ADV     0x0e
+
+// BIOS disk commands (AH)
+#define BD_RESET     0x00
+#define BD_CHECK     0x01
+#define BD_RDSECT    0x02
+#define BD_WRSECT    0x03
+#define BD_PARAMS    0x08
+
+// BIOS disk commands with parameters (AX)
+#define BD_READ(n)   ((BD_RDSECT << 8) | (n))
+#define BD_READ1     0x0201
+
+// CMOS ports (used for masking NMIs)
+#define	CMOS_ADDR    0x70
+#define	CMOS_DATA    0x71
+
+// important related commands
+#define NMI_ENABLE   0x00
+#define NMI_DISABLE  0x80
+
+/*
+** Physical Memory Map Table (0000:2D00 - 0000:7c00)
+**
+** Primarily used with the BIOS_MISC interrupt
+*/
+#define MMAP_SEG       0x02D0
+#define MMAP_DISP      0x0000
+#define MMAP_ADDR      ((MMAP_SEG << 4) + MMAP_DISP)
+#define MMAP_SECTORS   0x0a
+
+#define MMAP_ENT       24            /* bytes per entry */
+#define MMAP_MAX_ENTS  (BOOT_ADDR - MMAP_ADDR - 4) / 24
+
+#define MMAP_CODE      0xE820        /* int 0x15 code */
+#define MMAP_MAGIC_NUM 0x534D4150    /* for 0xE820 interrupt */
+
+#endif