fdreg.h

赵炯《Linux内核0.11完全注释》本书对Linux早期操作系统内核(v0.11)全部代码文件进行了详细全面的注释和说明

/*
 * This file contains some defines for the floppy disk controller.
 * Various sources. Mostly "IBM Microcomputers: A Programmers
 * Handbook", Sanches and Canton.
 */
#ifndef _FDREG_H
#define _FDREG_H

extern int ticks_to_floppy_on(unsigned int nr);
extern void floppy_on(unsigned int nr);
extern void floppy_off(unsigned int nr);
extern void floppy_select(unsigned int nr);
extern void floppy_deselect(unsigned int nr);

/* Fd controller regs. S&C, about page 340 */
#define FD_STATUS	0x3f4
#define FD_DATA		0x3f5
#define FD_DOR		0x3f2		/* Digital Output Register */
#define FD_DIR		0x3f7		/* Digital Input Register (read) */
#define FD_DCR		0x3f7		/* Diskette Control Register (write)*/

/* Bits of main status register */
#define STATUS_BUSYMASK	0x0F		/* drive busy mask */
#define STATUS_BUSY	0x10		/* FDC busy */
#define STATUS_DMA	0x20		/* 0- DMA mode */
#define STATUS_DIR	0x40		/* 0- cpu->fdc */
#define STATUS_READY	0x80		/* Data reg ready */

/* Bits of FD_ST0 */
#define ST0_DS		0x03		/* drive select mask */
#define ST0_HA		0x04		/* Head (Address) */
#define ST0_NR		0x08		/* Not Ready */
#define ST0_ECE		0x10		/* Equipment chech error */
#define ST0_SE		0x20		/* Seek end */
#define ST0_INTR	0xC0		/* Interrupt code mask */

/* Bits of FD_ST1 */
#define ST1_MAM		0x01		/* Missing Address Mark */
#define ST1_WP		0x02		/* Write Protect */
#define ST1_ND		0x04		/* No Data - unreadable */
#define ST1_OR		0x10		/* OverRun */
#define ST1_CRC		0x20		/* CRC error in data or addr */
#define ST1_EOC		0x80		/* End Of Cylinder */

/* Bits of FD_ST2 */
#define ST2_MAM		0x01		/* Missing Addess Mark (again) */
#define ST2_BC		0x02		/* Bad Cylinder */
#define ST2_SNS		0x04		/* Scan Not Satisfied */
#define ST2_SEH		0x08		/* Scan Equal Hit */
#define ST2_WC		0x10		/* Wrong Cylinder */
#define ST2_CRC		0x20		/* CRC error in data field */
#define ST2_CM		0x40		/* Control Mark = deleted */

/* Bits of FD_ST3 */
#define ST3_HA		0x04		/* Head (Address) */
#define ST3_TZ		0x10		/* Track Zero signal (1=track 0) */
#define ST3_WP		0x40		/* Write Protect */

/* Values for FD_COMMAND */
#define FD_RECALIBRATE	0x07		/* move to track 0 */
#define FD_SEEK		0x0F		/* seek track */
#define FD_READ		0xE6		/* read with MT, MFM, SKip deleted */
#define FD_WRITE	0xC5		/* write with MT, MFM */
#define FD_SENSEI	0x08		/* Sense Interrupt Status */
#define FD_SPECIFY	0x03		/* specify HUT etc */

/* DMA commands */
#define DMA_READ	0x46
#define DMA_WRITE	0x4A

#endif