1 9990f831 2024-10-05 benni [bits 16]
  2 9990f831 2024-10-05 benni [cpu 286]
  3 9990f831 2024-10-05 benni 
  4 9990f831 2024-10-05 benni %include "macros.inc"
  5 9990f831 2024-10-05 benni 
  6 9990f831 2024-10-05 benni ; Floppy Registers
  7 9990f831 2024-10-05 benni SRA equ 0x3f0 ; Status Register A		RO
  8 9990f831 2024-10-05 benni SRB equ 0x3f1 ; Status Register B		RO
  9 9990f831 2024-10-05 benni DOR equ 0x3f2 ; Digital Output Register		RW
 10 9990f831 2024-10-05 benni TDR equ 0x3f3 ; Tape Drive Register		RW
 11 9990f831 2024-10-05 benni MSR equ 0x3f4 ; Main Status Register		RO
 12 9990f831 2024-10-05 benni DSR equ 0x3f4 ; Datarate Select Register	WO
 13 9990f831 2024-10-05 benni DFF equ 0x3f5 ; Data FIFO			RW
 14 9990f831 2024-10-05 benni DIR equ 0x3f7 ; Digital Input Register		RO
 15 9990f831 2024-10-05 benni CCR equ 0x3f7 ; Configuration Control Register	WO
 16 9990f831 2024-10-05 benni 
 17 9990f831 2024-10-05 benni DOR_MOTD	equ 0x80 ; Drive Motor 3 ON
 18 9990f831 2024-10-05 benni DOR_MOTC	equ 0x40 ; Drive Motor 2 ON
 19 9990f831 2024-10-05 benni DOR_MOTB	equ 0x20 ; Drive Motor 1 ON
 20 9990f831 2024-10-05 benni DOR_MOTA	equ 0x10 ; Drive Motor 0 ON
 21 9990f831 2024-10-05 benni DOR_IRQ		equ 0x08 ; Enable IRQs and DMA
 22 9990f831 2024-10-05 benni DOR_NRESET	equ 0x04 ; 0=enter reset mode, 1=normal operation
 23 9990f831 2024-10-05 benni DOR_DSEL	equ 0x03 ; Select drive number mask
 24 9990f831 2024-10-05 benni 
 25 9990f831 2024-10-05 benni MSR_RQM		equ 0x80 ; It's OK (or mandatory) to exchange bytes with the FIFO IO port
 26 9990f831 2024-10-05 benni MSR_DIO		equ 0x40 ; FIFO expects an IN opcode
 27 9990f831 2024-10-05 benni MSR_NDMA	equ 0x20 ; Set while executing PIO mode read/write commands
 28 9990f831 2024-10-05 benni MSR_BSY		equ 0x10 ; Command Busy
 29 9990f831 2024-10-05 benni MSR_ACTD	equ 0x08 ; Drive 3 is seeking
 30 9990f831 2024-10-05 benni MSR_ACTC	equ 0x04 ; Drive 2 is seeking
 31 9990f831 2024-10-05 benni MSR_ACTB	equ 0x02 ; Drive 1 is seeking
 32 9990f831 2024-10-05 benni MSR_ACTA	equ 0x01 ; Drive 0 is seeking
 33 9990f831 2024-10-05 benni 
 34 9990f831 2024-10-05 benni DSR_288M	equ 0x03 ; 2.88M floppy (1Mbps)
 35 9990f831 2024-10-05 benni DSR_144M	equ 0x00 ; 1.44M floppy (500Kbps)
 36 9990f831 2024-10-05 benni 
 37 9990f831 2024-10-05 benni ; Floppy drive commands
 38 9990f831 2024-10-05 benni CMD_READ_TRACK		equ 2	; IRQ6
 39 9990f831 2024-10-05 benni CMD_SPECIFY		equ 3	; set drive parameters
 40 9990f831 2024-10-05 benni CMD_SENSE_DRIVE_STATUS	equ 4	
 41 9990f831 2024-10-05 benni CMD_WRITE_DATA		equ 5	; write to disk
 42 9990f831 2024-10-05 benni CMD_READ_DATA		equ 6	; read from disk
 43 9990f831 2024-10-05 benni CMD_RECALIBRATE		equ 7	; seek to cylinder 0
 44 9990f831 2024-10-05 benni CMD_SENSE_INTERRUPT	equ 8	; ack IRQ6, get status of last command
 45 9990f831 2024-10-05 benni CMD_WRITE_DELETED_DATA	equ 9
 46 9990f831 2024-10-05 benni CMD_READ_ID		equ 10	; IRQ6
 47 9990f831 2024-10-05 benni CMD_READ_DELETED_DATA	equ 12
 48 9990f831 2024-10-05 benni CMD_FORMAT_TRACK	equ 13
 49 9990f831 2024-10-05 benni CMD_DUMPREG		equ 14
 50 9990f831 2024-10-05 benni CMD_SEEK		equ 15	; seek both heads to cylinder X
 51 9990f831 2024-10-05 benni CMD_VERSION		equ 16	; used during initialization, once
 52 9990f831 2024-10-05 benni CMD_SCAN_EQUAL		equ 17
 53 9990f831 2024-10-05 benni CMD_PERPENDICULAR_MODE	equ 18	; used during initialization, once, maybe
 54 9990f831 2024-10-05 benni CMD_CONFIGURE		equ 19	; set controller parameters
 55 9990f831 2024-10-05 benni CMD_LOCK		equ 20	; protect controller parameters from reset
 56 9990f831 2024-10-05 benni CMD_VERIFY		equ 22
 57 9990f831 2024-10-05 benni CMD_SCAN_LOW_OR_EQUAL	equ 25
 58 9990f831 2024-10-05 benni CMD_SCAN_HIGH_OR_EQUAL	equ 29
 59 9990f831 2024-10-05 benni 
 60 9990f831 2024-10-05 benni CMD_MT	equ 0x80 ; multitrack mode
 61 9990f831 2024-10-05 benni CMD_MF	equ 0x40 ; "MFM" magnetic encoding mode. Always set for read/write/format/verify
 62 9990f831 2024-10-05 benni CMD_SK	equ 0x20 ; Skip mode. Skips "deleted sectors"
 63 9990f831 2024-10-05 benni 
 64 9990f831 2024-10-05 benni 
 65 9990f831 2024-10-05 benni section .text
 66 9990f831 2024-10-05 benni extern puthexb
 67 9990f831 2024-10-05 benni extern putchar
 68 9990f831 2024-10-05 benni extern puts
 69 9990f831 2024-10-05 benni extern panic
 70 9990f831 2024-10-05 benni global floppy_init
 71 9990f831 2024-10-05 benni floppy_init:
 72 9990f831 2024-10-05 benni 	lea bp, [fimsg]
 73 9990f831 2024-10-05 benni 	call puts
 74 9990f831 2024-10-05 benni 
 75 9990f831 2024-10-05 benni 	; read what types of floppy drives we have
 76 9990f831 2024-10-05 benni 	outb_slow 0x70, 0x90
 77 9990f831 2024-10-05 benni 	in al, 0x71
 78 9990f831 2024-10-05 benni 	mov byte [floppy_type], al
 79 9990f831 2024-10-05 benni 	call puthexb
 80 9990f831 2024-10-05 benni 
 81 9990f831 2024-10-05 benni 	mov al, 10
 82 9990f831 2024-10-05 benni 	call putchar
 83 9990f831 2024-10-05 benni 
 84 9990f831 2024-10-05 benni 	lea bp, [vermsg]
 85 9990f831 2024-10-05 benni 	call puts
 86 9990f831 2024-10-05 benni 
 87 9990f831 2024-10-05 benni 	call version
 88 9990f831 2024-10-05 benni 	call puthexb
 89 9990f831 2024-10-05 benni 
 90 9990f831 2024-10-05 benni 	mov al, 10
 91 9990f831 2024-10-05 benni 	call putchar
 92 9990f831 2024-10-05 benni 
 93 9990f831 2024-10-05 benni 	ret
 94 9990f831 2024-10-05 benni 
 95 9990f831 2024-10-05 benni wait_rqm:
 96 9990f831 2024-10-05 benni 	push cx
 97 9990f831 2024-10-05 benni 	mov cx, 128
 98 9990f831 2024-10-05 benni 
 99 9990f831 2024-10-05 benni .again:
100 9990f831 2024-10-05 benni 	dec cx
101 9990f831 2024-10-05 benni 	jz error
102 9990f831 2024-10-05 benni 
103 9990f831 2024-10-05 benni 	mov dx, MSR
104 9990f831 2024-10-05 benni 	in al, dx
105 9990f831 2024-10-05 benni 	test al, MSR_RQM
106 9990f831 2024-10-05 benni 	jz .again
107 9990f831 2024-10-05 benni 
108 9990f831 2024-10-05 benni 	pop cx
109 9990f831 2024-10-05 benni 	ret
110 9990f831 2024-10-05 benni 
111 9990f831 2024-10-05 benni version:
112 9990f831 2024-10-05 benni 	mov cx, 3
113 9990f831 2024-10-05 benni 
114 9990f831 2024-10-05 benni .begin:
115 9990f831 2024-10-05 benni 	dec cx
116 9990f831 2024-10-05 benni 	jz error
117 9990f831 2024-10-05 benni 
118 9990f831 2024-10-05 benni 	; wait for the controller
119 9990f831 2024-10-05 benni 	mov dx, MSR
120 9990f831 2024-10-05 benni 	in al, dx
121 9990f831 2024-10-05 benni 	and al, (MSR_RQM | MSR_DIO)
122 9990f831 2024-10-05 benni 	cmp al, MSR_RQM
123 9990f831 2024-10-05 benni 	jne .reset
124 9990f831 2024-10-05 benni 
125 9990f831 2024-10-05 benni 	; send version command
126 9990f831 2024-10-05 benni 	mov al, CMD_VERSION
127 9990f831 2024-10-05 benni 	mov dx, DFF
128 9990f831 2024-10-05 benni 	out dx, al
129 9990f831 2024-10-05 benni 
130 9990f831 2024-10-05 benni 	; wait for version byte
131 9990f831 2024-10-05 benni 	call wait_rqm
132 9990f831 2024-10-05 benni 	test al, MSR_DIO
133 9990f831 2024-10-05 benni 	jz error
134 9990f831 2024-10-05 benni 
135 9990f831 2024-10-05 benni 	; read version byte
136 9990f831 2024-10-05 benni 	mov dx, DFF
137 9990f831 2024-10-05 benni 	in al, dx
138 9990f831 2024-10-05 benni 	mov bl, al
139 9990f831 2024-10-05 benni 
140 9990f831 2024-10-05 benni 	; wait for completion
141 9990f831 2024-10-05 benni 	call wait_rqm
142 9990f831 2024-10-05 benni 
143 9990f831 2024-10-05 benni 	; verify result
144 9990f831 2024-10-05 benni 	mov dx, MSR
145 9990f831 2024-10-05 benni 	in al, dx
146 9990f831 2024-10-05 benni 	and al, (MSR_RQM | MSR_BSY | MSR_DIO)
147 9990f831 2024-10-05 benni 	cmp al, MSR_RQM
148 9990f831 2024-10-05 benni 	jne .retry
149 9990f831 2024-10-05 benni 	mov al, bl
150 9990f831 2024-10-05 benni 	ret
151 9990f831 2024-10-05 benni 
152 9990f831 2024-10-05 benni .retry:
153 9990f831 2024-10-05 benni 	push cx
154 9990f831 2024-10-05 benni 	lea bp, [rtmsg]
155 9990f831 2024-10-05 benni 	call puts
156 9990f831 2024-10-05 benni 	pop cx
157 9990f831 2024-10-05 benni 	jmp .begin
158 9990f831 2024-10-05 benni 
159 9990f831 2024-10-05 benni .reset:
160 9990f831 2024-10-05 benni 	push cx
161 9990f831 2024-10-05 benni 	call reset
162 9990f831 2024-10-05 benni 	pop cx
163 9990f831 2024-10-05 benni 	jmp .begin
164 9990f831 2024-10-05 benni 
165 9990f831 2024-10-05 benni reset:
166 9990f831 2024-10-05 benni 	lea bp, [rsmsg]
167 9990f831 2024-10-05 benni 	jmp puts
168 9990f831 2024-10-05 benni 
169 9990f831 2024-10-05 benni error:
170 9990f831 2024-10-05 benni 	lea bp, [errstr]
171 9990f831 2024-10-05 benni 	jmp panic
172 9990f831 2024-10-05 benni 
173 9990f831 2024-10-05 benni ; ax LBA
174 9990f831 2024-10-05 benni ; return:
175 9990f831 2024-10-05 benni ; - bx	cyl
176 9990f831 2024-10-05 benni ; - cx	head
177 9990f831 2024-10-05 benni ; - dx	sector
178 9990f831 2024-10-05 benni lba_to_cha:
179 9990f831 2024-10-05 benni 	xor dx, dx
180 9990f831 2024-10-05 benni 	mov cx, 36
181 9990f831 2024-10-05 benni 	div cx
182 9990f831 2024-10-05 benni 	mov bx, ax	; cyl
183 9990f831 2024-10-05 benni 	mov ax, dx
184 9990f831 2024-10-05 benni 	xor dx, dx
185 9990f831 2024-10-05 benni 	mov cx, 18
186 9990f831 2024-10-05 benni 	div cx
187 9990f831 2024-10-05 benni 	mov cx, ax	; head
188 9990f831 2024-10-05 benni 	inc dx		; sector
189 9990f831 2024-10-05 benni 	ret
190 9990f831 2024-10-05 benni 
191 9990f831 2024-10-05 benni section .rodata
192 9990f831 2024-10-05 benni errstr:
193 9990f831 2024-10-05 benni 	db "An error occured in the floppy driver", 10, 0
194 9990f831 2024-10-05 benni fimsg:
195 9990f831 2024-10-05 benni 	db "Floppy drive type: 0x", 0
196 9990f831 2024-10-05 benni vermsg:
197 9990f831 2024-10-05 benni 	db "Floppy drive version: 0x", 0
198 9990f831 2024-10-05 benni rsmsg:
199 9990f831 2024-10-05 benni 	db "Resetting floppy drive...", 10, 0
200 9990f831 2024-10-05 benni rtmsg:
201 9990f831 2024-10-05 benni 	db "Retrying last operating", 10, 0
202 9990f831 2024-10-05 benni 
203 9990f831 2024-10-05 benni section .bss
204 9990f831 2024-10-05 benni floppy_type:
205 9990f831 2024-10-05 benni 	resb 1