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Assembly Source File | 1991-11-06 | 14.0 KB | 655 lines

; ; Simple SCSI Device Driver ; PAGE 76,132 INCLUDE options.inc INCLUDE equ.inc INCLUDE struct.inc ife oldcode .286 else .8086 pusha macro push ax push bx push cx push dx push si push di endm popa macro pop di pop si pop dx pop cx pop bx pop ax endm endif ; ; Start of Code and Data ; _TEXT segment word public 'CODE' assume cs:_TEXT, ds:_TEXT, es:_TEXT org 0 ; ; Device Header Required By DOS ; scsi: tape_link_ofs dw disk_link_ofs ;Forward Link tape_link_seg dw -1 dw 0C800h ;Char Device dw tape_strategy ;Address of 1st DOS Call dw dev_interrupt ;Address of 2nd DOS Call db 'SCSITAPE' ;Device Name disk_link_ofs dw -1 ;Forward Link disk_link_seg dw -1 if large_drives dw 06042h ;Ioctl R/W, Block Device, Non-IBM, Get/Set, 32 bit else dw 06040h ;Ioctl R/W, Block Device, Non-IBM, Get/Set endif dw disk_strategy ;Address of 1st DOS Call dw dev_interrupt ;Address of 2nd DOS Call disk_count db 0 ;Number of Disks Present db 7 dup(?) ; ; Work Space For Our Device Driver ; even rh_off dw ? ;Request Header Offset rh_seg dw ? ;Request Header Segment rh_type db ? ;Request Type write_flag db FALSE ;TRUE When Tape Write Seen read_flag db FALSE ;TRUE When Tape Read Seen error_flag db FALSE ;TRUE When Tape Error Seen load_flag db TRUE ;TRUE When Tape should Load/Unload cur_drive db -1 vol_id db 'NO NAME ',0 ; ; The Original INT 24 Vector ; vect_int_24 equ word ptr 4 * 24h orig_int_24 dd ? ;Original INT 24 Vector ; ; Define our own personal Stack ; even new_stack db STACK_SIZE-2 dup (?) ;Our Local Stack new_stack_top dw ? stack_ptr dw ? ;Old Stack Pointer stack_seg dw ? ;Old Stack Segment ; ; Command Table ; cmdtab label byte ;* = Char Only Devices dw INITIALIZATION ;Initialization dw MEDIA_CHECK ;Media Check (Block Only) dw GET_BPB ;Build BPB (Block Only) dw unknown ;IOCTL Read dw READ ;Read Data dw done ;*Non Destructive Read dw done ;*Read Status dw done ;*Flush Read Buffer dw WRITE ;Write Data dw WRITE_VERIFY ;Write With Verify dw done ;*Write Status dw done ;*Flush Write Buffer dw WRITE_IOCTL ;IOCTL Write dw OPEN_DEV ;Device Open dw CLOSE_DEV ;Device Close dw done ;Removable Check dw unknown ;*Write Until Busy dw unknown ;Unknown Call dw unknown ;Unknown Call dw IOCTL ;Generic Ioctl dw unknown ;Unknown Call dw unknown ;Unknown Call dw unknown ;Unknown Call dw GET_DEV ;Get Device dw SET_DEV ;Set Device ; ; Int 24 (Fatal Error Handler) ; ; The test for our tape device only works because the ; device header for the tape is located at the start ; of the driver binary. ; our_int_24 proc far push ax mov ax,cs ;Is it our Segment cmp bp,ax jnz not_our_tape cmp si,0 ;Is it the Tape Device jnz not_our_tape pop ax mov al,3 ;Fail the System Call iret not_our_tape: pop ax jmp cs:orig_int_24 ;Pass the Request On our_int_24 endp ; ; Strategy Procedure ; disk_strategy proc far mov cs:rh_seg,es ;Save Request Header Ptr Segment mov cs:rh_off,bx ;Save Request Header Ptr Offset mov cs:rh_type,DISK_REQUEST ret disk_strategy endp tape_strategy proc far mov cs:rh_seg,es ;Save Request Header Ptr Segment mov cs:rh_off,bx ;Save Request Header Ptr Offset mov cs:rh_type,TAPE_REQUEST ret tape_strategy endp ; ; Interrupt Procedure ; dev_interrupt proc far pushf ;Save Machine State On Entry cli push ds push es push ax push bx push cx push dx push si push di push bp mov cs:stack_seg,ss ;Save Old Stack mov cs:stack_ptr,sp mov ax,cs ;Save us the Segment Override Crap mov ds,ax mov es,ax mov ss,ax ;Setup Our Local Stack lea ax,new_stack_top mov sp,ax sti ;We're Safe Now ; ; Perform branch based on the command passed in the Request Header ; mov es,rh_seg ;Point us at the Request Header mov bx,rh_off mov al,es:[bx].rh_cmd ;Get Command Code rol al,1 ;Get offset into table lea di,cmdtab ;Get address of command table mov ah,0 ;Clear hi order byte add di,ax ;Add offset jmp word ptr [di] ;Jump Indirect ; ; Command Procedures ; INITIALIZATION: cmp rh_type,TAPE_REQUEST ;Is this SCSITAPE: Init? jz init_skip mov al,es:[bx].rh0_drv_ltr ;Save the starting Drive add al,041h mov cur_drive,al call initial ;Setup if use_kludge call patch_us_in endif mov bx,rh_off mov es,rh_seg init_skip: lea ax,initial ;Set The Break Address mov es:[bx].rh0_brk_ofs,ax mov es:[bx].rh0_brk_seg,cs mov al,disk_count ;Number of Disk Devices Supported mov es:[bx].rh0_nunits,al lea dx,bpb_array ;BPB Array mov es:[bx].rh0_bpb_tbo,dx mov es:[bx].rh0_bpb_tbs,cs jmp done ; ; Has the Media Changed ; MEDIA_CHECK: call find_unit jc mc_jmp_err mov di,cur_unit mov al,[di].unit_mcheck ;Get Initial Status mov [di].unit_mcheck,1 ;Always OK from then on mov es:[bx].rh1_md_stat,al lea dx,vol_id ;Address of Volume ID mov es:[bx].rh1_volid_ofs,dx mov es:[bx].rh1_volid_seg,cs jmp done mc_jmp_err: jmp bad_unit ; ; Get Disk Parameter Block ; GET_BPB: call find_unit jc get_jmp_err mov dx,cur_bpb ;Address of BPB mov es:[bx].rh2_pbpbo,dx mov es:[bx].rh2_pbpbs,cs jmp done get_jmp_err: jmp bad_unit ; ; Read some data from the disk/tape ; READ: cmp rh_type,DISK_REQUEST jz read_a_disk mov ax,tape_unit ;Do We Have a Tape? cmp ax,-1 jz read_jmp_err1 mov cur_unit,ax call tape_read jc read_jmp_err2 jmp done read_a_disk: call find_unit jc read_jmp_err1 call disk_read jc read_jmp_err2 jmp done read_jmp_err1: jmp bad_unit read_jmp_err2: jmp bad_read ; ; Write some data to the disk/tape ; WRITE equ $ WRITE_VERIFY: cmp rh_type,DISK_REQUEST jz write_a_disk mov ax,tape_unit ;Do We Have a Tape? cmp ax,-1 jz write_jmp_err1 mov cur_unit,ax call tape_write jc write_jmp_err2 jmp done write_a_disk: call find_unit jc write_jmp_err1 call disk_write jc write_jmp_err2 jmp done write_jmp_err1: jmp bad_unit write_jmp_err2: jmp bad_write write_jmp_err3: jmp unknown ; ; Write Ioctl Packet ; WRITE_IOCTL: cmp rh_type,DISK_REQUEST jz ioctl_a_disk mov ax,tape_unit ;Do we have a SCSITAPE? cmp ax,-1 jz write_jmp_err1 mov cur_unit,ax jmp short ioctl_do ioctl_a_disk: call find_unit jc write_jmp_err1 ioctl_do: call scsi_ioctl_write jc write_jmp_err3 jmp done ; ; Special Control Functions ; IOCTL: call find_unit jc ioctl_jmp_err1 call scsi_ioctl jc ioctl_jmp_err2 ;Must have been a Verify error jmp done ioctl_jmp_err1: jmp bad_unit ioctl_jmp_err2: jmp bad_read ; ; Open Tape Device ; OPEN_DEV: mov di,tape_unit cmp di,-1 ;Do We have a SCSITAPE: Unit? jnz open_tape jmp bad_unit open_tape: mov cur_unit,di ;New Current Unit lea bx,[di].unit_sense ;Buffer Offset push ds ;Buffer Segment pop es mov cx,size sense ;Buffer Size lea di,cmd_sense ;Command call docmd jc open_err cmp load_flag,TRUE ;Should we LOAD? jnz open_ok ife mini_inquire mov di,cur_unit ;Check Unit Type mov ax,word ptr [di].unit_inq_buf.inq_manufact lea di,cmd_rewind ;Default to Rewind cmp ax,'ET' ;If this is a TEAC Unit jz open_rewind endif lea di,cmd_load ;Now Load Tape mov [di].load_cmd_type,LOAD_TAPE open_rewind: call docmd jnc open_ok call scsi_sense open_err: jmp general open_ok: mov write_flag,FALSE ;No Writes Seen mov read_flag,FALSE ;No Reads Seen mov error_flag,FALSE ;No Error Yet if use_kludge mov opened_flag,TRUE ;We are Open endif mov ax,0 ;Patch Ourselves into mov es,ax ;the INT 24 Vector mov ax,es:[vect_int_24] ;Offset mov word ptr orig_int_24,ax lea ax,our_int_24 mov es:[vect_int_24],ax mov ax,es:[vect_int_24+2] ;Segment mov word ptr orig_int_24+2,ax mov ax,cs mov es:[vect_int_24+2],ax jmp done ; ; Close Tape Device ; CLOSE_DEV: mov di,tape_unit cmp di,-1 ;Do We have a SCSITAPE: Unit? jnz close_tape jmp bad_unit close_tape: mov ax,0 ;Restore mov es,ax ;the INT 24 Vector mov word ptr orig_int_24,ax mov es:[vect_int_24],ax ;Offset mov word ptr orig_int_24+2,ax mov es:[vect_int_24+2],ax ;Segment mov cur_unit,di ;New Current Unit cmp error_flag,TRUE ;Any Tape Errors jz skip_extras cmp write_flag,TRUE ;Were We Writing? jnz not_writing lea di,cmd_twritefm ;End Tape with FM(s) mov [di].fm_cmd_cnt_b0,CLOSE_FM_CNT call docmd jnc skip_extras call get_sense jmp short skip_extras not_writing: cmp read_flag,TRUE ;Were We Reading? jnz skip_extras cmp load_flag,TRUE ;No Rewind? jz skip_extras lea di,cmd_space ;Space Forward mov [di].space_cmd_code,1 ;By FileMark mov [di].space_cmd_cnt2,0 mov [di].space_cmd_cnt1,0 mov [di].space_cmd_cnt0,1 call docmd jnc skip_extras call get_sense skip_extras: cmp load_flag,TRUE ;Should we Unload? jnz close_ok ife mini_inquire mov di,cur_unit ;Check Unit Type mov ax,word ptr [di].unit_inq_buf.inq_manufact lea di,cmd_rewind cmp ax,'ET' ;Rewind instead of jz close_rewind ;Unload TEAC Unit endif lea di,cmd_load ;Now Unload Tape mov [di].load_cmd_type,UNLOAD_TAPE close_rewind: call docmd jnc close_ok call scsi_sense jmp general close_ok: jmp done ; ; Get Device Assignment ; GET_DEV: mov es:[bx].rh_unit,0 jmp done ; ; Set Device Assignment ; SET_DEV: jmp done bad_unit: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,8001h jmp short done unknown: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,8003h jmp short done bad_write: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,800Ah jmp short done bad_read: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,800Bh jmp short done general: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,800Ch jmp short done busy: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,0200h done: mov es,rh_seg ;Point us at the Request Header mov bx,rh_off or es:[bx].rh_status,0100h cli ;Make sure we're left alone mov ax,cs:stack_seg ;Restore DOS Stack mov ss,ax mov ax,cs:stack_ptr mov sp,ax pop bp ;Restore All Registers pop di pop si pop dx pop cx pop bx pop ax pop es pop ds popf ret INCLUDE units.asm INCLUDE subs.asm INCLUDE ioctl.asm INCLUDE dump.asm if use_kludge INCLUDE kludge.asm endif ; ; End of Program ; Stuff Placed Here Gets Handed Back To DOS For Re-use ; initial proc near lea dx,hello_msg ;Tell them the driver version call puts push cs pop dx lea bx,seg_msg_value call hex2asc4 lea dx,seg_msg ;And Were We Loaded call puts call scsi_reset ;Reset the bus mov cx,0 ;Scan for devices scan: mov ax,cx add al,030h mov scan_dev,al mov ax,1 ;Create Select Bit shl ax,cl mov di,cur_unit mov [di].unit_select,al mov [di].unit_num_drv,0 ;No Drives to start with mov al,disk_count ;We will start with mov [di].unit_1st_drv,al ;Drive Number if any lea dx,scan_dev ;Print the device number call puts call scsi_inquire ;Inquire as to its type jnc scan_inq_ok lea dx,no_dev ;If the error was cmp al,CNOCONNECT ;'No Such Device' jz puts_jmp lea dx,dumb_disk_msg ;Assume it is a 'SCSI I' jmp short scan_is_drv ;Old style disk scan_inq_ok: mov di,cur_unit if mini_inquire lea dx,disk_dev_msg else lea dx,[di].unit_inq_buf.inq_manufact mov [di].unit_inq_term,'$' endif mov al,[di].unit_inq_buf.inq_dev_type or al,al ;Look at device type jz scan_is_drv if mini_inquire lea dx,tape_dev_msg endif cmp tape_unit,-1 ;Do We Already Have A Tape? jnz puts_jmp call puts ;Make this our SCSITAPE: Unit mov tape_unit,di lea dx,tape_msg puts_jmp: jmp scan_puts scan_is_drv: call puts ;Output the Device String call scsi_capacity ;Inquire as to its size lea dx,err_size jc scan_puts ;Do not use unknown drives lea dx,crlf call puts scan_next_drv: mov di,cur_unit mov al,disk_count ;Number Of Drives Found inc al mov disk_count,al mov al,[di].unit_num_drv ;We have a valid Drive inc al mov [di].unit_num_drv,al mov al,cur_drive ;Get Current Drive Letter mov drv_msg_let,al ;Insert it in message inc al ;Bump Drive Letter mov cur_drive,al call make_bpb ;Setup the BPB for this drive mov di,cur_bpb ;Current Working BPB if large_drives mov dx,[di].bpb_ts_msw mov ax,[di].bpb_ts_lsw else mov dx,0 mov ax,[di].bpb_ts endif mov bx,2048 div bx inc ax lea bx,drv_msg_size call bin_ascii mov bx,bpb_hw_mark ;Get the BPB High Water Mark inc bx ;Bump HW Mark for next time inc bx mov ax,[bx] ;Get the BPB mov cur_bpb,ax ;Make it the current BPB mov bpb_hw_mark,bx lea dx,drv_msg call puts ife large_drives mov bx,cur_unit mov ah,0 mov al,[bx].unit_num_drv ;Insert Drive Offset dec al ;Into BPB for this Drive mov [di].bpb_hs_msw,ax mov al,[bx].unit_cap_buf.cap_sectors_b3 or al,[bx].unit_cap_buf.cap_sectors_b2 or al,[bx].unit_cap_buf.cap_sectors_b1 or al,[bx].unit_cap_buf.cap_sectors_b0 jnz scan_next_drv ;Room left for another Drive endif jmp short scan_next scan_puts: call puts lea dx,crlf call puts scan_next: inc cx cmp cx,MAXUNIT ;End of devices? jg scan_exit mov bx,cx ;Bump to next unit shl bx,1 mov ax,word ptr unit_array[bx] mov cur_unit,ax jmp scan scan_exit: lea dx,crlf call puts ret initial endp ; ; Data Area Used Only During Initialization ; hello_msg db 0dh,0ah,'SCSI Device Driver Version 2.0, ' if oldcode db '8086 Flavor',0Dh,0Ah,'$' else db '80286 Flavor',0Dh,0Ah,'$' endif seg_msg db 'Driver Loaded At Segment ' seg_msg_value db '0000',0dh,0ah,'$' scan_dev db 'X - ','$' no_dev db '(No Installed Device)$' err_size db '(Unknown Size)$' drv_msg db ' - Drive ' drv_msg_let db 'X: ' drv_msg_size db 'XXXXXX Meg',0dh,0ah,'$' tape_msg db 0dh,0ah,' - Is The SCSITAPE: Device$' dumb_disk_msg db 'UNKNOWN DUMB DISK $' crlf db 0dh,0ah,'$' if mini_inquire disk_dev_msg db 'Disk Device $' tape_dev_msg db 'Tape Device $' endif dev_interrupt endp _TEXT ends end