; Temporary Runix kernel v2.0 file for debug - 22/11/2021 ; (re-write kernel for test by using previous version without a major defect) ; **************************************************************************** ; Retro UNIX 386 v1 Kernel (v0.2.2.3) - SYS0.INC ; Last Modification: 17/07/2022 ; ---------------------------------------------------------------------------- ; Derived from 'Retro UNIX 8086 v1' source code by Erdogan Tan ; (v0.1 - Beginning: 11/07/2012) ; ; Derived from UNIX Operating System (v1.0 for PDP-11) ; (Original) Source Code by Ken Thompson (1971-1972) ; ; ; ; Retro UNIX 8086 v1 - U0.ASM (28/07/2014) //// UNIX v1 -> u0.s ; ; **************************************************************************** sys_init: ; 23/02/2022 ; 08/01/2022 ; 01/01/2022 ; 26/12/2021 ; 27/11/2021 ; 22/11/2021 - Retro UNIX 386 v2 (test) compatibility modification ; 18/10/2015 ; 28/08/2015 ; 24/08/2015 ; 14/08/2015 ; 24/07/2015 ; 02/07/2015 ; 01/07/2015 ; 23/06/2015 ; 15/04/2015 ; 13/04/2015 ; 11/03/2015 (Retro UNIX 386 v1 - Beginning) ; 28/07/2014 (Retro UNIX 8086 v1) ; ;call ldrv_init ; Logical drive description tables initialization ; ;; 14/02/2014 ;; 14/07/2013 ;mov ax, 41 ;mov [rootdir], ax ;mov [u.cdir], ax ;and al, 1 ; 15/04/2015 ; 27/11/2021 ; 18/04/2021 - Retro UNIX 386 v2 xor eax, eax inc al ; eax = 1 (root directory inode) ; runix v2 fs mov [rootdir], eax ; = 1 ; 28/10/2021 (32 bit) mov [u.cdir], eax ; 28/10/2021 (32 bit) mov [u.uno], al ; = 1 ;mov [mpid], ax ; 1 ;mov [p.pid], ax ; 1 ; 01/01/2022 mov [mpid], al mov [p.pid], al mov [p.stat], al ; SRUN, 05/02/2014 ; mov al, time_count ; 30/08/2013 mov [u.quant], al ; 14/07/2013 ; 02/07/2015 mov eax, [k_page_dir] mov [u.pgdir], eax ; reset ; 18/10/2015 ;sub eax, eax ;mov [u.ppgdir], eax ; 0 ; ; 23/02/2022 ;call epoch ;mov [s.time], eax ; 13/03/2015 ; 17/07/2013 call bf_init ; buffer initialization ; 23/02/2022 ; (save sysinit time on sb0) call epoch mov [s.time], eax ; 13/03/2015 ; 23/06/2015 call allocate_page ;;jc error ;jc panic ; jc short panic (01/07/2015) ; 05/12/2021 jnc short sysinit_1 jmp panic sysinit_1: mov [u.upage], eax ; user structure page mov [p.upage], eax ; call clear_page ; ; 14/08/2015 cli ; 14/03/2015 ; 17/01/2014 call sp_init ; serial port initialization ; 14/08/2015 sti ; ; 30/06/2015 ;mov esi, kernel_init_ok_msg ;call print_msg ; xor bl, bl ; video page 0 vp_clr_nxt: ; clear video pages (reset cursor positions) call vp_clr ; 17/07/2013 inc bl cmp bl, 8 jb short vp_clr_nxt ; ; 24/07/2015 ;push KDATA ;push esp ;mov [tss.esp0], esp ;mov word [tss.ss0], KDATA ; ; 08/01/2022 ; 24/08/2015 ;; temporary (01/07/2015) ;mov byte [u.quant], time_count ; 4 ; ; it is not needed here ! ;;inc byte [u.kcall] ; 'the caller is kernel' sign dec byte [sysflg] ; FFh = ready for system call ; 0 = executing a system call ;;sys _msg, kernel_init_ok_msg, 255, 0 ; ;;; 06/08/2015 ;;;call getch ; wait for a key stroke ;;mov ecx, 0FFFFFFFh ;;sys_init_msg_wait: ;; push ecx ;; mov al, 1 ;; mov ah, [ptty] ; active (current) video page ;; call getc_n ;; pop ecx ;; jnz short sys_init_msg_ok ;; loop sys_init_msg_wait ; ;;sys_init_msg_ok: ; 28/08/2015 (initial settings for the 1st 'rswap') push KDATA ; ss push esp pushfd push KCODE ; cs push init_exec ; eip mov [u.sp], esp push ds push es push fs push gs pushad mov [u.usp], esp call wswap ; save current user (u) structure, user registers ; and interrupt return components (for IRET) popad pop ax ; gs pop ax ; fs pop ax ; es pop ax ; ds pop eax ; eip (init_exec) pop ax ; cs (KCODE) pop eax ; E-FLAGS pop eax ; esp pop ax ; ss (KDATA) ; ; 26/12/2021 ([u.ppgdir] is zero already) ;xor eax, eax ; 0 ;mov [u.ppgdir], eax ; reset (to zero) for '/etc/init' ; ; 02/07/2015 ; [u.pgdir ] = [k_page_dir] ; [u.ppgdir] = 0 (page dir of the parent process) ; (The caller is os kernel sign for 'sysexec') init_exec: ; 13/03/2013 ; 24/07/2013 mov ebx, init_file mov ecx, init_argp ; EBX contains 'etc/init' asciiz file name address ; ECX contains address of argument list pointer ; ;dec byte [sysflg] ; FFh = ready for system call ; 0 = executing a system call sys _exec ; execute file jnc short panic ; mov esi, etc_init_err_msg ; 22/11/2021 ;call print_msg jmp short key_to_reboot ;align 4 init_argp: dd init_file, 0 ; 23/06/2015 (dw -> dd) init_file: ; 24/08/2015 db '/etc/init', 0 panic: ; 13/03/2015 (Retro UNIX 386 v1) ; 07/03/2014 (Retro UNIX 8086 v1) mov esi, panic_msg key_to_reboot: ; 22/11/2021 call print_msg ;key_to_reboot: ; 15/11/2015 call getch ; wait for a character from the current tty ; mov al, 0Ah mov bl, [ptty] ; [active_page] mov ah, 07h ; Black background, ; light gray forecolor call write_tty jmp cpu_reset print_msg: ; 01/07/2015 ; 13/03/2015 (Retro UNIX 386 v1) ; 07/03/2014 (Retro UNIX 8086 v1) ; (Modified registers: EAX, EBX, ECX, EDX, ESI, EDI) ; ; lodsb pmsg1: push esi movzx ebx, byte [ptty] mov ah, 07h ; Black background, light gray forecolor call write_tty pop esi lodsb and al, al jnz short pmsg1 retn ctrlbrk: ; 06/02/2022 ; 04/12/2021 (Retro UNIX 386 v1.2) ; 12/11/2015 ; 13/03/2015 (Retro UNIX 386 v1) ; 06/12/2013 (Retro UNIX 8086 v1) ; ; INT 1Bh (control+break) handler ; ; Retro Unix 8086 v1 feature only! ; cmp word [u.intr], 0 jna short cbrk4 cbrk0: ; 12/11/2015 ; 06/12/2013 cmp word [u.quit], 0 jz short cbrk4 ; ; 20/09/2013 ;push ax ; 04/12/2021 push eax ; 06/02/2022 ; (repetitive ctrl+brk check) mov ax, [u.quit] inc ax ; 0FFFFh -> 0 jz short cbrk3 ; 06/12/2013 mov al, [ptty] ; ; 12/11/2015 ; ; ctrl+break (EOT, CTRL+D) from serial port ; or ctrl+break from console (pseudo) tty ; (!redirection!) ; cmp al, 8 ; serial port tty nums > 7 jb short cbrk1 ; console (pseudo) tty ; ; Serial port interrupt handler sets [ptty] ; to the port's tty number (as temporary). ; ; If active process is using a stdin or ; stdout redirection (by the shell), ; console tty keyboard must be available ; to terminate running process, ; in order to prevent a deadlock. ; push edx movzx edx, byte [u.uno] cmp al, [edx+p.ttyc-1] ; console tty (rw) pop edx je short cbrk2 cbrk1: inc al ; [u.ttyp] : 1 based tty number ; 06/12/2013 cmp al, [u.ttyp] ; recent open tty (r) je short cbrk2 cmp al, [u.ttyp+1] ; recent open tty (w) jne short cbrk3 cbrk2: ;; 06/12/2013 ;mov ax, [u.quit] ;and ax, ax ;jz short cbrk3 ; ;xor ax, ax ; 0 ;dec ax ; 04/12/2021 xor eax, eax ; 0 dec eax ; 0FFFFFFFFh ; 0FFFFh = 'ctrl+brk' keystroke mov [u.quit], ax cbrk3: ;pop ax ; 04/12/2021 pop eax cbrk4: retn com2_int: ; 08/01/2022 (Retro UNIX 386 v1.2) ; 07/11/2015 ; 24/10/2015 ; 23/10/2015 ; 14/03/2015 (Retro UNIX 386 v1 - Beginning) ; 28/07/2014 (Retro UNIX 8086 v1) ; < serial port 2 interrupt handler > ; mov [esp], eax ; overwrite call return address ;;push eax ; 08/01/2022 sub eax, eax mov al, 9 ;mov ax, 9 jmp short comm_int com1_int: ; 07/11/2015 ; 24/10/2015 mov [esp], eax ; overwrite call return address ; 23/10/2015 ;push eax ; 08/01/2022 sub eax, eax mov al, 8 ;mov ax, 8 comm_int: ; 08/01/2022 ; 20/11/2015 ; 18/11/2015 ; 17/11/2015 ; 16/11/2015 ; 09/11/2015 ; 08/11/2015 ; 07/11/2015 ; 06/11/2015 (serial4.asm, 'serial') ; 01/11/2015 ; 26/10/2015 ; 23/10/2015 push ebx push esi push edi push ds push es ; 18/11/2015 mov ebx, cr3 push ebx ; **** ; push ecx ; *** push edx ; ** ; mov ebx, KDATA mov ds, bx mov es, bx ; mov ecx, [k_page_dir] mov cr3, ecx ; 20/11/2015 ; Interrupt identification register mov dx, 2FAh ; COM2 ; cmp al, 8 ja short com_i0 ; ; 08/01/2022 (Retro UNIX 386 v1.1) ; 20/11/2015 ; 17/11/2015 ; 16/11/2015 ; 15/11/2015 ; 24/10/2015 ; 14/03/2015 (Retro UNIX 386 v1 - Beginning) ; 28/07/2014 (Retro UNIX 8086 v1) ; < serial port 1 interrupt handler > ; inc dh ; 3FAh ; COM1 Interrupt id. register com_i0: ;push eax ; * ; 07/11/2015 mov byte [ccomport], al ; 09/11/2015 ;movzx ebx, ax ; 8 or 9 ; 08/01/2022 mov ebx, eax ; 8 or 9 ; 17/11/2015 ; reset request for response status mov [ebx+req_resp-8], ah ; 0 ; ; 20/11/2015 in al, dx ; read interrupt id. register JMP $+2 ; I/O DELAY and al, 4 ; received data available? jz short com_eoi ; (transmit. holding reg. empty) ; ; 20/11/2015 sub dl, 3FAh-3F8h ; data register (3F8h, 2F8h) in al, dx ; read character ;JMP $+2 ; I/O DELAY ; 08/11/2015 ; 07/11/2015 mov esi, ebx mov edi, ebx add esi, rchar - 8 ; points to last received char add edi, schar - 8 ; points to last sent char mov [esi], al ; received char (current char) ; query and al, al jnz short com_i2 ; response ; 17/11/2015 ; set request for response status inc byte [ebx+req_resp-8] ; 1 ; add dx, 3FDh-3F8h ; (3FDh, 2FDh) in al, dx ; read line status register JMP $+2 ; I/O DELAY and al, 20h ; transmitter holding reg. empty? jz short com_eoi ; no mov al, 0FFh ; response sub dx, 3FDh-3F8h ; data port (3F8h, 2F8h) out dx, al ; send on serial port ; 17/11/2015 cmp byte [edi], 0 ; query ? (schar) jne short com_i1 ; no mov [edi], al ; 0FFh (responded) com_i1: ; 17/11/2015 ; reset request for response status (again) dec byte [ebx+req_resp-8] ; 0 jmp short com_eoi com_i2: ; 08/11/2015 cmp al, 0FFh ; (response ?) je short com_i3 ; (check for response signal) ; 07/11/2015 cmp al, 04h ; EOT jne short com_i4 ; EOT = 04h (End of Transmit) - 'CTRL + D' ;(an EOT char is supposed as a ctrl+brk from the terminal) ; 08/11/2015 ; ptty -> tty 0 to 7 (pseudo screens) xchg bl, [ptty] ; tty number (8 or 9) call ctrlbrk xchg [ptty], bl ; (restore ptty value and BL value) ;mov al, 04h ; EOT ; 08/11/2015 jmp short com_i4 com_i3: ; 08/11/2015 ; If 0FFh has been received just after a query ; (schar, ZERO), it is a response signal. ; 17/11/2015 cmp byte [edi], 0 ; query ? (schar) ja short com_i4 ; no ; reset query status (schar) mov [edi], al ; 0FFh inc al ; 0 com_i4: ; 27/07/2014 ; 09/07/2014 shl bl, 1 add ebx, ttychr ; 23/07/2014 (always overwrite) ;;cmp word [ebx], 0 ;;ja short com_eoi ; mov [ebx], ax ; Save ascii code ; scan code = 0 com_eoi: ;mov al, 20h ;out 20h, al ; end of interrupt ; ; 07/11/2015 ;pop eax ; * mov al, byte [ccomport] ; current COM port ; al = tty number (8 or 9) call wakeup com_iret: ; 23/10/2015 pop edx ; ** pop ecx ; *** ; 18/11/2015 ;pop eax ; **** ;mov cr3, eax ;jmp iiret jmp iiretp ;iiretp: ; 01/09/2015 ; ; 28/08/2015 ; pop eax ; (*) page directory ; mov cr3, eax ;iiret: ; ; 22/08/2014 ; mov al, 20h ; END OF INTERRUPT COMMAND TO 8259 ; out 20h, al ; 8259 PORT ; ; ; pop es ; pop ds ; pop edi ; pop esi ; pop ebx ; 29/08/2014 ; pop eax ; iretd sp_init: ; 08/01/2022 (Retro UNIX 386 v1.2) ; 07/11/2015 ; 29/10/2015 ; 26/10/2015 ; 23/10/2015 ; 29/06/2015 ; 14/03/2015 (Retro UNIX 386 v1 - 115200 baud) ; 28/07/2014 (Retro UNIX 8086 v1 - 9600 baud) ; Initialization of Serial Port Communication Parameters ; (COM1 base port address = 3F8h, COM1 Interrupt = IRQ 4) ; (COM2 base port address = 2F8h, COM1 Interrupt = IRQ 3) ; ; ((Modified registers: EAX, ECX, EDX, EBX)) ; ; INPUT: (29/06/2015) ; AL = 0 for COM1 ; 1 for COM2 ; AH = Communication parameters ; ; (*) Communication parameters (except BAUD RATE): ; Bit 4 3 2 1 0 ; -PARITY-- STOP BIT -WORD LENGTH- ; this one --> 00 = none 0 = 1 bit 11 = 8 bits ; 01 = odd 1 = 2 bits 10 = 7 bits ; 11 = even ; Baud rate setting bits: (29/06/2015) ; Retro UNIX 386 v1 feature only ! ; Bit 7 6 5 | Baud rate ; ------------------------ ; value 0 0 0 | Default (Divisor = 1) ; 0 0 1 | 9600 (12) ; 0 1 0 | 19200 (6) ; 0 1 1 | 38400 (3) ; 1 0 0 | 14400 (8) ; 1 0 1 | 28800 (4) ; 1 1 0 | 57600 (2) ; 1 1 1 | 115200 (1) ; References: ; (1) IBM PC-XT Model 286 BIOS Source Code ; RS232.ASM --- 10/06/1985 COMMUNICATIONS BIOS (RS232) ; (2) Award BIOS 1999 - ATORGS.ASM ; (3) http://wiki.osdev.org/Serial_Ports ; ; Set communication parameters for COM1 (= 03h) ; mov ebx, com1p ; COM1 parameters mov dx, 3F8h ; COM1 ; 29/10/2015 mov cx, 301h ; divisor = 1 (115200 baud) call sp_i3 ; call A4 test al, 80h jz short sp_i0 ; OK.. ; Error ! ;mov dx, 3F8h sub dl, 5 ; 3FDh -> 3F8h ;mov cx, 30Eh ; divisor = 12 (9600 baud) ; 08/01/2022 mov cl, 0Eh ; cx = 30Eh, divisor = 12 (9600 baud) call sp_i3 ; call A4 test al, 80h jnz short sp_i1 sp_i0: ; (Note: Serial port interrupts will be disabled here...) ; (INT 14h initialization code disables interrupts.) ; mov byte [ebx], 0E3h ; 11100011b call sp_i5 ; 29/06/2015 sp_i1: inc ebx mov dx, 2F8h ; COM2 ; 29/10/2015 ;mov cx, 301h ; divisor = 1 (115200 baud) ; 08/01/2022 mov cl, 01h ; cx = 301h, divisor = 1 (115200 baud) call sp_i3 ; call A4 test al, 80h jz short sp_i2 ; OK.. ; Error ! ;mov dx, 2F8h sub dl, 5 ; 2FDh -> 2F8h ;mov cx, 30Eh ; divisor = 12 (9600 baud) ; 08/01/2022 mov cl, 0Eh ; cx = 30Eh, divisor = 12 (9600 baud) call sp_i3 ; call A4 test al, 80h jnz short sp_i7 sp_i2: mov byte [ebx], 0E3h ; 11100011b sp_i6: ;; COM2 - enabling IRQ 3 ; 08/01/2022 mov ah, 0F7h ; enable IRQ 3 (COM2) ; 07/11/2015 ; 26/10/2015 ;pushf ;cli ;; ;;mov dx, 2FCh ; modem control register ;mov dl, 0FCh ; 08/01/2022 ;in al, dx ; read register ;JMP $+2 ; I/O DELAY ;or al, 8 ; enable bit 3 (OUT2) ;out dx, al ; write back to register ;JMP $+2 ; I/O DELAY ;;mov dx, 2F9h ; interrupt enable register ;mov dl, 0F9h ; 08/01/2022 ;in al, dx ; read register ;JMP $+2 ; I/O DELAY ;;or al, 1 ; receiver data interrupt enable and ;or al, 3 ; transmitter empty interrupt enable ;out dx, al ; write back to register ;JMP $+2 ; I/O DELAY ;in al, 21h ; read interrupt mask register ;JMP $+2 ; I/O DELAY ;and al, 0F7h ; enable IRQ 3 (COM2) ;out 21h, al ; write back to register ; ; 08/01/2022 pushf call sp_i8 ; 23/10/2015 mov eax, com2_int mov [com2_irq3], eax ; 26/10/2015 popf sp_i7: retn sp_i3: ;A4: ;----- INITIALIZE THE COMMUNICATIONS PORT ; 28/10/2015 inc dl ; 3F9h (2F9h) ; 3F9h, COM1 Interrupt enable register mov al, 0 out dx, al ; disable serial port interrupt JMP $+2 ; I/O DELAY add dl, 2 ; 3FBh (2FBh) ; COM1 Line control register (3FBh) mov al, 80h out dx, al ; SET DLAB=1 ; divisor latch access bit ;----- SET BAUD RATE DIVISOR ; 26/10/2015 sub dl, 3 ; 3F8h (2F8h) ; register for least significant byte ; of the divisor value mov al, cl ; 1 out dx, al ; 1 = 115200 baud (Retro UNIX 386 v1) ; 2 = 57600 baud ; 3 = 38400 baud ; 6 = 19200 baud ; 12 = 9600 baud (Retro UNIX 8086 v1) JMP $+2 ; I/O DELAY sub al, al inc dl ; 3F9h (2F9h) ; register for most significant byte ; of the divisor value out dx, al ; 0 JMP $+2 ; I/O DELAY ; mov al, ch ; 3 ; 8 data bits, 1 stop bit, no parity ;and al, 1Fh ; Bits 0,1,2,3,4 add dl, 2 ; 3FBh (2FBh) ; Line control register out dx, al JMP $+2 ; I/O DELAY ; 29/10/2015 dec dl ; 3FAh (2FAh) ; FIFO Control register (16550/16750) xor al, al ; 0 out dx, al ; Disable FIFOs (reset to 8250 mode) JMP $+2 sp_i4: ;A18: ;----- COMM PORT STATUS ROUTINE ; 29/06/2015 (line status after modem status) add dl, 4 ; 3FEh (2FEh) ; Modem status register sp_i4s: in al, dx ; GET MODEM CONTROL STATUS JMP $+2 ; I/O DELAY mov ah, al ; PUT IN (AH) FOR RETURN dec dl ; 3FDh (2FDh) ; POINT TO LINE STATUS REGISTER ; dx = 3FDh for COM1, 2FDh for COM2 in al, dx ; GET LINE CONTROL STATUS ; AL = Line status, AH = Modem status retn sp_status: ; 29/06/2015 ; 27/06/2015 (Retro UNIX 386 v1) ; Get serial port status mov dx, 3FEh ; Modem status register (COM1) sub dh, al ; dh = 2 for COM2 (al = 1) ; dx = 2FEh for COM2 jmp short sp_i4s sp_setp: ; Set serial port communication parameters ; 08/01/2022 ; 24/12/2021 (Retro UNIX 386 v1.2) ; 07/11/2015 ; 29/10/2015 ; 29/06/2015 ; Retro UNIX 386 v1 feature only ! ; ; INPUT: ; AL = 0 for COM1 ; 1 for COM2 ; AH = Communication parameters (*) ; OUTPUT: ; CL = Line status ; CH = Modem status ; If cf = 1 -> Error code in [u.error] ; 'invalid parameter !' ; or ; 'device not ready !' error ; ; (*) Communication parameters (except BAUD RATE): ; Bit 4 3 2 1 0 ; -PARITY-- STOP BIT -WORD LENGTH- ; this one --> 00 = none 0 = 1 bit 11 = 8 bits ; 01 = odd 1 = 2 bits 10 = 7 bits ; 11 = even ; Baud rate setting bits: (29/06/2015) ; Retro UNIX 386 v1 feature only ! ; Bit 7 6 5 | Baud rate ; ------------------------ ; value 0 0 0 | Default (Divisor = 1) ; 0 0 1 | 9600 (12) ; 0 1 0 | 19200 (6) ; 0 1 1 | 38400 (3) ; 1 0 0 | 14400 (8) ; 1 0 1 | 28800 (4) ; 1 1 0 | 57600 (2) ; 1 1 1 | 115200 (1) ; ; (COM1 base port address = 3F8h, COM1 Interrupt = IRQ 4) ; (COM2 base port address = 2F8h, COM1 Interrupt = IRQ 3) ; ; ((Modified registers: EAX, ECX, EDX, EBX)) ; mov dx, 3F8h mov ebx, com1p ; COM1 control byte offset cmp al, 1 ja short sp_invp_err jb short sp_setp1 ; COM1 (AL = 0) dec dh ; 2F8h inc ebx ; COM2 control byte offset sp_setp1: ; 29/10/2015 mov [ebx], ah movzx ecx, ah shr cl, 5 ; -> baud rate index and ah, 1Fh ; communication parameters except baud rate mov al, [ecx+b_div_tbl] mov cx, ax call sp_i3 mov cx, ax ; CL = Line status, CH = Modem status test al, 80h jz short sp_setp2 mov byte [ebx], 0E3h ; Reset to initial value (11100011b) stp_dnr_err: mov dword [u.error], ERR_DEV_NOT_RDY ; 'device not ready !' ; CL = Line status, CH = Modem status stc retn sp_setp2: cmp dh, 2 ; COM2 (2F?h) ;jna sp_i6 ; COM1 (3F?h) ; 24/12/2021 ja short sp_i5 jmp sp_i6 sp_i5: ; 08/01/2022 mov ah, 0EFh ; enable IRQ 4 (COM1) ; 07/11/2015 ; 26/10/2015 ; 29/06/2015 ; ;; COM1 - enabling IRQ 4 ;pushf ;cli ;;mov dx, 3FCh ; modem control register ;mov dl, 0FCh ; 08/01/2022 ;in al, dx ; read register ;JMP $+2 ; I/O DELAY ;or al, 8 ; enable bit 3 (OUT2) ;out dx, al ; write back to register ;JMP $+2 ; I/O DELAY ;;mov dx, 3F9h ; interrupt enable register ;mov dl, 0F9h ; 08/01/2022 ;in al, dx ; read register ;JMP $+2 ; I/O DELAY ;;or al, 1 ; receiver data interrupt enable and ;or al, 3 ; transmitter empty interrupt enable ;out dx, al ; write back to register ;JMP $+2 ; I/O DELAY ;in al, 21h ; read interrupt mask register ;JMP $+2 ; I/O DELAY ;and al, 0EFh ; enable IRQ 4 (COM1) ;out 21h, al ; write back to register ; ; 08/01/2022 pushf call sp_i8 ; 23/10/2015 mov eax, com1_int mov [com1_irq4], eax ; 26/10/2015 popf retn sp_i8: ; 08/01/2022 ;pushf cli ; ;mov dx, 2FCh ; 3FCh ; modem control register mov dl, 0FCh in al, dx ; read register JMP $+2 ; I/O DELAY or al, 8 ; enable bit 3 (OUT2) out dx, al ; write back to register JMP $+2 ; I/O DELAY ;mov dx, 2F9h ; 3F9h ; interrupt enable register mov dl, 0F9h in al, dx ; read register JMP $+2 ; I/O DELAY ;or al, 1 ; receiver data interrupt enable and or al, 3 ; transmitter empty interrupt enable out dx, al ; write back to register JMP $+2 ; I/O DELAY in al, 21h ; read interrupt mask register JMP $+2 ; I/O DELAY ;and al, 0F7h ; 0EFh ; enable IRQ 3 (COM2) and al, ah ; 0F7h or 0EFh out 21h, al ; write back to register ; ;popf retn sp_invp_err: mov dword [u.error], ERR_INV_PARAMETER ; 'invalid parameter !' xor ecx, ecx dec ecx ; 0FFFFh stc retn ; 29/10/2015 b_div_tbl: ; Baud rate divisor table (115200/divisor) db 1, 12, 6, 3, 8, 4, 1 ; Retro UNIX 8086 v1 - UNIX.ASM (01/09/2014) epoch: ; 04/12/2021 (Retro UNIX 386 v1.2) ; 15/03/2015 (Retro UNIX 386 v1 - 32 bit version) ; 09/04/2013 (Retro UNIX 8086 v1 - UNIX.ASM) ; 'epoch' procedure prototype: ; UNIXCOPY.ASM, 10/03/2013 ; 14/11/2012 ; unixboot.asm (boot file configuration) ; version of "epoch" procedure in "unixproc.asm" ; 21/7/2012 ; 15/7/2012 ; 14/7/2012 ; Erdogan Tan - RETRO UNIX v0.1 ; compute current date and time as UNIX Epoch/Time ; UNIX Epoch: seconds since 1/1/1970 00:00:00 ; ; ((Modified registers: EAX, EDX, ECX, EBX)) ; call get_rtc_time ; Return Current Time xchg ch,cl mov [hour], cx xchg dh,dl mov [second], dx ; call get_rtc_date ; Return Current Date xchg ch,cl mov [year], cx xchg dh,dl mov [month], dx ; mov cx, 3030h ; mov al, [hour] ; Hour ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov [hour], al mov al, [hour+1] ; Minute ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov [minute], al mov al, [second] ; Second ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov [second], al mov ax, [year] ; Year (century) ;push ax ; 04/12/2021 push eax ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov ah, 100 mul ah mov [year], ax ;pop ax ; 04/12/2021 pop eax mov al, ah ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL add [year], ax mov al, [month] ; Month ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov [month], al mov al, [month+1] ; Day ; AL <= BCD number) db 0D4h,10h ; Undocumented inst. AAM ; AH = AL / 10h ; AL = AL MOD 10h aad ; AX= AH*10+AL mov [day], al _epoch: ; 17/07/2022 ; 15/03/2015 (Retro UNIX 386 v1 - 32 bit modification) ; 09/04/2013 (Retro UNIX 8086 v1) ; ; ((Modified registers: EAX, EDX, EBX)) ; ; Derived from DALLAS Semiconductor ; Application Note 31 (DS1602/DS1603) ; 6 May 1998 sub eax, eax mov ax, [year] sub ax, 1970 mov edx, 365 mul edx xor ebx, ebx mov bl, [month] dec bl shl bl, 1 ;sub edx, edx mov dx, [EBX+DMonth] mov bl, [day] dec bl add eax, edx add eax, ebx ; EAX = days since 1/1/1970 mov dx, [year] sub dx, 1969 ;shr dx, 1 ;shr dx, 1 ; 17/07/2022 shr edx, 2 ; (year-1969)/4 add eax, edx ; + leap days since 1/1/1970 cmp byte [month], 2 ; if past february jna short cte1 mov dx, [year] and dx, 3 ; year mod 4 jnz short cte1 ; and if leap year add eax, 1 ; add this year's leap day (february 29) cte1: ; compute seconds since 1/1/1970 mov edx, 24 mul edx mov dl, [hour] add eax, edx ; EAX = hours since 1/1/1970 00:00:00 ;mov ebx, 60 mov bl, 60 mul ebx mov dl, [minute] add eax, edx ; EAX = minutes since 1/1/1970 00:00:00 ;mov ebx, 60 mul ebx mov dl, [second] add eax, edx ; EAX -> seconds since 1/1/1970 00:00:00 retn get_rtc_time: ; 15/03/2015 ; Derived from IBM PC-XT Model 286 BIOS Source Code ; BIOS2.ASM ---- 10/06/1985 BIOS INTERRUPT ROUTINES ; INT 1Ah ; (AH) = 02H READ THE REAL TIME CLOCK AND RETURN WITH, : ; (CH) = HOURS IN BCD (00-23) : ; (CL) = MINUTES IN BCD (00-59) : ; (DH) = SECONDS IN BCD (00-59) : ; (DL) = DAYLIGHT SAVINGS ENABLE (00-01). : ; RTC_20: ; GET RTC TIME cli CALL UPD_IPR ; CHECK FOR UPDATE IN PROCESS JC short RTC_29 ; EXIT IF ERROR (CY= 1) MOV AL, CMOS_SECONDS ; SET ADDRESS OF SECONDS CALL CMOS_READ ; GET SECONDS MOV DH, AL ; SAVE MOV AL, CMOS_REG_B ; ADDRESS ALARM REGISTER CALL CMOS_READ ; READ CURRENT VALUE OF DSE BIT AND AL, 00000001B ; MASK FOR VALID DSE BIT MOV DL, AL ; SET [DL] TO ZERO FOR NO DSE BIT MOV AL, CMOS_MINUTES ; SET ADDRESS OF MINUTES CALL CMOS_READ ; GET MINUTES MOV CL, AL ; SAVE MOV AL, CMOS_HOURS ; SET ADDRESS OF HOURS CALL CMOS_READ ; GET HOURS MOV CH, AL ; SAVE CLC ; SET CY= 0 RTC_29: sti RETn ; RETURN WITH RESULT IN CARRY FLAG get_rtc_date: ; 15/03/2015 ; Derived from IBM PC-XT Model 286 BIOS Source Code ; BIOS2.ASM ---- 10/06/1985 BIOS INTERRUPT ROUTINES ; INT 1Ah ; (AH) = 04H READ THE DATE FROM THE REAL TIME CLOCK AND RETURN WITH,: ; (CH) = CENTURY IN BCD (19 OR 20) : ; (CL) = YEAR IN BCD (00-99) : ; (DH) = MONTH IN BCD (01-12) : ; (DL) = DAY IN BCD (01-31). ; RTC_40: ; GET RTC DATE cli CALL UPD_IPR ; CHECK FOR UPDATE IN PROCESS JC short RTC_49 ; EXIT IF ERROR (CY= 1) MOV AL, CMOS_DAY_MONTH ; ADDRESS DAY OF MONTH CALL CMOS_READ ; READ DAY OF MONTH MOV DL, AL ; SAVE MOV AL, CMOS_MONTH ; ADDRESS MONTH CALL CMOS_READ ; READ MONTH MOV DH, AL ; SAVE MOV AL, CMOS_YEAR ; ADDRESS YEAR CALL CMOS_READ ; READ YEAR MOV CL, AL ; SAVE MOV AL, CMOS_CENTURY ; ADDRESS CENTURY LOCATION CALL CMOS_READ ; GET CENTURY BYTE MOV CH, AL ; SAVE CLC ; SET CY=0 RTC_49: sti RETn ; RETURN WITH RESULTS IN CARRY FLAG set_date_time: convert_from_epoch: ; 02/06/2022 (BugFix) ; 15/03/2015 (Retro UNIX 386 v1 - 32 bit version) ; 20/06/2013 (Retro UNIX 8086 v1) ; 'convert_from_epoch' procedure prototype: ; UNIXCOPY.ASM, 10/03/2013 ; ; ((Modified registers: EAX, EDX, ECX, EBX)) ; ; Derived from DALLAS Semiconductor ; Application Note 31 (DS1602/DS1603) ; 6 May 1998 ; ; INPUT: ; EAX = Unix (Epoch) Time ; xor edx, edx ; 02/06/2022 xor ecx, ecx xor ebx, ebx ;mov ecx, 60 mov cl, 60 div ecx ;mov [imin], eax ; whole minutes ; since 1/1/1970 ;mov [second], dx ; leftover seconds mov [second], dl ; 02/06/2022 sub edx, edx div ecx ;mov [ihrs], eax ; whole hours ; ; since 1/1/1970 ;mov [minute], dx ; leftover minutes mov [minute], dl ; 02/06/2022 xor edx, edx ;mov cx, 24 mov cl, 24 div ecx ;mov [iday], ax ; whole days ; since 1/1/1970 ;mov [hour], dx ; leftover hours mov [hour], dl ; 02/06/2022 add eax, 365+366 ; whole day since ; 1/1/1968 ;mov [iday], ax push eax sub edx, edx mov ecx, (4*365)+1 ; 4 years = 1461 days div ecx pop ecx ;mov [lday], ax ; count of quadyrs (4 years) ;push dx ; 02/06/2022 push edx ;mov [qday], dx ; days since quadyr began cmp dx, 31+29 ; if past feb 29 then cmc ; add this quadyr's leap day adc eax, 0 ; to # of qadyrs (leap days) ;mov [lday], ax ; since 1968 ;mov cx, [iday] xchg ecx, eax ; ECX = lday, EAX = iday sub eax, ecx ; iday - lday mov ecx, 365 xor edx, edx ; EAX = iday-lday, EDX = 0 div ecx ;mov [iyrs], ax ; whole years since 1968 ;jday = iday - (iyrs*365) - lday ;mov [jday], dx ; days since 1/1 of current year ;add eax, 1968 add ax, 1968 ; compute year mov [year], ax ;mov cx, dx ; 02/06/2022 mov ecx, edx ;mov dx, [qday] ;pop dx ; 02/06/2022 pop edx cmp dx, 365 ; if qday <= 365 and qday >= 60 ja short cfe1 ; jday = jday +1 cmp dx, 60 ; if past 2/29 and leap year then cmc ; add a leap day to the # of whole adc cx, 0 ; days since 1/1 of current year cfe1: ;mov [jday], cx ;mov bx, 12 ; estimate month ;sub ebx, ebx ; 02/06/2022 mov bl, 12 mov dx, 366 ; mday, max. days since 1/1 is 365 and ax, 11b ; year mod 4 (and dx, 3) cfe2: ; Month calculation ; 0 to 11 (11 to 0) ;cmp cx, dx ; mday = # of days passed from 1/1 ; 02/06/2022 cmp ecx, edx jnb short cfe3 ;dec bx ; month = month - 1 dec bl ;shl bx, 1 shl bl, 1 mov dx, [ebx+DMonth] ; # elapsed days at 1st of month ;shr bx, 1 ; bx = month - 1 (0 to 11) ; 02/06/2022 shr bl, 1 cmp bl, 1 ;cmp bx, 1 ; if month > 2 and year mod 4 = 0 jna short cfe2 ; then mday = mday + 1 or al, al ; if past 2/29 and leap year then jnz short cfe2 ; add leap day (to mday) ;inc dx ; mday = mday + 1 inc edx jmp short cfe2 cfe3: ;inc bx ; -> bx = month, 1 to 12 ; 02/06/2022 inc bl ;mov [month], bx mov [month], bl ;sub cx, dx ; day = jday - mday + 1 sub ecx, edx ;inc cx inc cl ;mov [day], cx mov [day], cl ; 02/06/2022 ; eax, ebx, ecx, edx is changed at return ; output -> ; [year], [month], [day], [hour], [minute], [second] ; 02/06/2022 (BugFix) _set_date: mov ax, [year] mov ch, 20h ; century (bcd) sub ax, 2000 jnc short set_date mov ch, 19h ; century (bcd) add ax, 100 ; 02/06/2022 ; 15/03/2015 (Retro UNIX 386 v1 - 32 bit version) ; 20/06/2013 (Retro UNIX 8086 v1) set_date: ;mov al, [year+1] ;aam ; ah = al / 10, al = al mod 10 ;db 0D5h, 10h ; Undocumented inst. AAD ; ; AL = AH * 10h + AL ;mov ch, al ; century (BCD) ;mov al, [year] ; al = year (0-99) ; 01/06/2022 aam ; ah = al / 10, al = al mod 10 db 0D5h, 10h ; Undocumented inst. AAD ; AL = AH * 10h + AL mov cl, al ; year (BCD) mov al, [month] aam ; ah = al / 10, al = al mod 10 db 0D5h, 10h ; Undocumented inst. AAD ; AL = AH * 10h + AL mov dh, al ; month (BCD) mov al, [day] aam ; ah = al / 10, al = al mod 10 db 0D5h, 10h ; Undocumented inst. AAD ; AL = AH * 10h + AL ; 02/06/2022 (BugFix) mov dl, al ; day (BCD) ; Set real-time clock date call set_rtc_date set_time: ; Read real-time clock time ; (get day light saving time bit status) cli CALL UPD_IPR ; CHECK FOR UPDATE IN PROCESS ; cf = 1 -> al = 0 jc short stime1 MOV AL, CMOS_REG_B ; ADDRESS ALARM REGISTER CALL CMOS_READ ; READ CURRENT VALUE OF DSE BIT stime1: sti AND AL, 00000001B ; MASK FOR VALID DSE BIT MOV DL, AL ; SET [DL] TO ZERO FOR NO DSE BIT ; DL = 1 or 0 (day light saving time) ; mov al, [hour] aam ; ah = al / 10, al = al mod 10 db 0D5h,10h ; Undocumented inst. AAD ; AL = AH * 10h + AL mov ch, al ; hour (BCD) mov al, [minute] aam ; ah = al / 10, al = al mod 10 db 0D5h,10h ; Undocumented inst. AAD ; AL = AH * 10h + AL mov cl, al ; minute (BCD) mov al, [second] aam ; ah = al / 10, al = al mod 10 db 0D5h,10h ; Undocumented inst. AAD ; AL = AH * 10h + AL mov dh, al ; second (BCD) ; Set real-time clock time ; call set_rtc_time set_rtc_time: ; 15/04/2015 (257, POSTEQU.INC -> H EQU 256, X EQU H+1) ; 15/03/2015 ; Derived from IBM PC-XT Model 286 BIOS Source Code ; BIOS2.ASM ---- 10/06/1985 BIOS INTERRUPT ROUTINES ; INT 1Ah ; (AH) = 03H SET THE REAL TIME CLOCK USING, : ; (CH) = HOURS IN BCD (00-23) : ; (CL) = MINUTES IN BCD (00-59) : ; (DH) = SECONDS IN BCD (00-59) : ; (DL) = 01 IF DAYLIGHT SAVINGS ENABLE OPTION, ELSE 00. : ; : ; NOTE: (DL)= 00 IF DAYLIGHT SAVINGS TIME ENABLE IS NOT ENABLED. : ; (DL)= 01 ENABLES TWO SPECIAL UPDATES THE LAST SUNDAY IN : ; APRIL (1:59:59 --> 3:00:00 AM) AND THE LAST SUNDAY IN : ; OCTOBER (1:59:59 --> 1:00:00 AM) THE FIRST TIME. : ; RTC_30: ; SET RTC TIME cli CALL UPD_IPR ; CHECK FOR UPDATE IN PROCESS JNC short RTC_35 ; GO AROUND IF CLOCK OPERATING CALL RTC_STA ; ELSE TRY INITIALIZING CLOCK RTC_35: MOV AH, DH ; GET TIME BYTE - SECONDS MOV AL, CMOS_SECONDS ; ADDRESS SECONDS CALL CMOS_WRITE ; UPDATE SECONDS MOV AH, CL ; GET TIME BYTE - MINUTES MOV AL, CMOS_MINUTES ; ADDRESS MINUTES CALL CMOS_WRITE ; UPDATE MINUTES MOV AH, CH ; GET TIME BYTE - HOURS MOV AL, CMOS_HOURS ; ADDRESS HOURS CALL CMOS_WRITE ; UPDATE ADDRESS ;MOV AX, X*CMOS_REG_B ; ADDRESS ALARM REGISTER MOV AX, 257*CMOS_REG_B ; CALL CMOS_READ ; READ CURRENT TIME AND AL, 01100010B ; MASK FOR VALID BIT POSITIONS OR AL, 00000010B ; TURN ON 24 HOUR MODE AND DL, 00000001B ; USE ONLY THE DSE BIT OR AL, DL ; GET DAY LIGHT SAVINGS TIME BIT (OSE) XCHG AH, AL ; PLACE IN WORK REGISTER AND GET ADDRESS CALL CMOS_WRITE ; SET NEW ALARM BITS CLC ; SET CY= 0 sti RETn ; RETURN WITH CY= 0 set_rtc_date: ; 15/04/2015 (257, POSTEQU.INC -> H EQU 256, X EQU H+1) ; 15/03/2015 ; Derived from IBM PC-XT Model 286 BIOS Source Code ; BIOS2.ASM ---- 10/06/1985 BIOS INTERRUPT ROUTINES ; INT 1Ah ; (AH) = 05H SET THE DATE INTO THE REAL TIME CLOCK USING, : ; (CH) = CENTURY IN BCD (19 OR 20) : ; (CL) = YEAR IN BCD (00-99) : ; (DH) = MONTH IN BCD (01-12) : ; (DL) = DAY IN BCD (01-31). ; RTC_50: ; SET RTC DATE cli CALL UPD_IPR ; CHECK FOR UPDATE IN PROCESS JNC short RTC_55 ; GO AROUND IF NO ERROR CALL RTC_STA ; ELSE INITIALIZE CLOCK RTC_55: MOV AX, CMOS_DAY_WEEK ; ADDRESS OF DAY OF WEEK BYTE CALL CMOS_WRITE ; LOAD ZEROS TO DAY OF WEEK MOV AH, DL ; GET DAY OF MONTH BYTE MOV AL, CMOS_DAY_MONTH ; ADDRESS DAY OF MONTH BYTE CALL CMOS_WRITE ; WRITE OF DAY OF MONTH REGISTER MOV AH, DH ; GET MONTH MOV AL, CMOS_MONTH ; ADDRESS MONTH BYTE CALL CMOS_WRITE ; WRITE MONTH REGISTER MOV AH, CL ; GET YEAR BYTE MOV AL, CMOS_YEAR ; ADDRESS YEAR REGISTER CALL CMOS_WRITE ; WRITE YEAR REGISTER MOV AH, CH ; GET CENTURY BYTE MOV AL, CMOS_CENTURY ; ADDRESS CENTURY BYTE CALL CMOS_WRITE ; WRITE CENTURY LOCATION ;MOV AX, X*CMOS_REG_B ; ADDRESS ALARM REGISTER MOV AX, 257*CMOS_REG_B ; CALL CMOS_READ ; READ CURRENT SETTINGS AND AL, 07FH ; CLEAR 'SET BIT' XCHG AH, AL ; MOVE TO WORK REGISTER CALL CMOS_WRITE ; AND START CLOCK UPDATING CLC ; SET CY= 0 sti RETn ; RETURN CY=0 ; 15/03/2015 RTC_STA: ; INITIALIZE REAL TIME CLOCK mov ah, 26h mov al, CMOS_REG_A ; ADDRESS REGISTER A AND LOAD DATA MASK CALL CMOS_WRITE ; INITIALIZE STATUS REGISTER A mov ah, 82h mov al, CMOS_REG_B ; SET "SET BIT" FOR CLOCK INITIALIZATION CALL CMOS_WRITE ; AND 24 HOUR MODE TO REGISTER B MOV AL, CMOS_REG_C ; ADDRESS REGISTER C CALL CMOS_READ ; READ REGISTER C TO INITIALIZE MOV AL, CMOS_REG_D ; ADDRESS REGISTER D ;CALL CMOS_READ ; READ REGISTER D TO INITIALIZE ;RETn ; 06/02/2022 jmp CMOS_READ ; 15/03/2015 ; IBM PC/XT Model 286 BIOS source code ----- 10/06/85 (test4.asm) CMOS_WRITE: ; WRITE (AH) TO LOCATION (AL) pushf ; SAVE INTERRUPT ENABLE STATUS AND FLAGS ;push ax ; SAVE WORK REGISTER VALUES rol al, 1 ; MOVE NMI BIT TO LOW POSITION stc ; FORCE NMI BIT ON IN CARRY FLAG rcr al, 1 ; HIGH BIT ON TO DISABLE NMI - OLD IN CY cli ; DISABLE INTERRUPTS out CMOS_PORT, al ; ADDRESS LOCATION AND DISABLE NMI mov al, ah ; GET THE DATA BYTE TO WRITE out CMOS_DATA, al ; PLACE IN REQUESTED CMOS LOCATION mov al, CMOS_SHUT_DOWN*2 ; GET ADDRESS OF DEFAULT LOCATION rcr al, 1 ; PUT ORIGINAL NMI MASK BIT INTO ADDRESS out CMOS_PORT, al ; SET DEFAULT TO READ ONLY REGISTER nop ; I/O DELAY in al, CMOS_DATA ; OPEN STANDBY LATCH ;pop ax ; RESTORE WORK REGISTERS popf RETn bf_init: ; 21/03/2022 (Retro UNIX 386 v1.2) ; 28/11/2021 ; 14/08/2015 ; 02/07/2015 ; 01/07/2015 ; 15/04/2015 (Retro UNIX 386 v1 - Beginning) ; Buffer (pointer) initialization ! ; ; 17/07/2013 - 24/07/2013 ; Retro UNIX 8086 v1 (U9.ASM) ; (Retro UNIX 8086 v1 feature only !) ; mov edi, bufp mov eax, buffer + (nbuf*520) sub edx, edx dec dl xor ecx, ecx dec ecx bi0: sub eax, 520 ; 8 header + 512 data stosd mov esi, eax mov [esi], edx ; 000000FFh ; Not a valid device sign mov [esi+4], ecx ; 0FFFFFFFFh ; Not a valid block number sign cmp eax, buffer ja short bi0 mov eax, sb0 stosd mov eax, sb1 stosd mov esi, eax ; offset sb1 mov [esi], edx ; 000000FFh ; Not a valid device sign mov [esi+4], ecx ; 0FFFFFFFFh ; Not a valid block number sign ; 14/08/2015 ;call rdev_init ;retn ; ----- Root file system initialization ; 21/03/2022 - Retro UNIX 386 v1.2 ; (Retro UNIX -runix- v2 file system) ; 28/11/2021 rdev_init: ; root device, super block buffer initialization ; 14/08/2015 ; Retro UNIX 386 v1 feature only ! ; ; NOTE: Disk partitions (file systems), logical ; drive initialization, partition's start sector etc. ; will be coded here, later in 'ldrv_init' movzx eax, byte [boot_drv] rdi_0: cmp al, 80h jb short rdi_1 sub al, 7Eh ; 80h = 2 (hd0), 81h = 3 (hd1) rdi_1: mov [rdev], al ; 21/03/2022 ;cmp al, 2 ;jnb short rdi_2 or al, al jnz short rdi_2 ; hard disk boot ; floppy disk boot xor edx, edx ; device number = 0 ; (& fglags = 0) ; eax = 0 ; boot sector address = 0 ;jmp short rdi_5 jmp short rdi_4 rdi_2: ; load masterboot sector ; to get runix v2 partition's boot sector address ; mov ebx, mbrbuf ; masterboot buffer header addr ;mov [ebx], eax mov [ebx], al ;sub al, al ;; eax = 0 ;mov [ebx+4], eax ; masterboot sector address call diskio jnc short rdi_3 rdi_err: mov esi, disk_read_err_msg jmp key_to_reboot rdi_3: ; [ebx+8] = masterboot buffer (data) address ;cmp word [ebx+8+510], 0AA55h ;jc short rdi_err lea esi, [ebx+8] call runix_p_bs ; return start sector address of ; retro unix v2 partition in esi ;;jc short rdi_err ; 'retn' ;jnc short rdi_4 ; Runix v2 partition not found !? ; 21/03/2022 ; ((Here, if cf is 1, that means, ; runix v2 partition not found ; in the MBR partition table. ; But, at least, there is a valid ; runix v2 boot sector on the disk ; which started the kernel. ; So, runix v2 boot sector code ; may -must- be on physical sector 0 ; and then the superblock may be ; -must be- on physical sector 1.)) ;sub eax, eax ; eax = 0 ;rdi_4: mov edx, [ebx] ; restore device number in dl ;rdi_5: rdi_4: mov ebx, sb0 ; super block buffer (header) inc eax ; default sector address of the sb ; (boot sector address + 1) ;mov [ebx], eax ;mov al, 1 ; eax = 1 ;mov [ebx+4], eax ; super block address on disk ; 21/03/2022 mov [ebx], edx ; device number in DL ; (other bytes -flags- are zero) mov [ebx+4], eax ; superblock address on disk ;call diskio ;retn ; 28/11/2021 ;jmp diskio ; 21/03/2022 call diskio jc short rdi_err ; 21/03/2022 ; Note: If superblock is defective or SB sector ; address is wrong, "ERROR: /etc/init !?" ; message will appear after here. ; ..because /etc/init inode will not be found.. ; So, i am not writing SB validation ; (check) code here. ; ; ((Also, if we are here, everything should be normal!)) retn disk_read_err_msg: ; 21/03/2022 - Retro UNIX 386 v1.2 db 07h, 0Dh, 0Ah db "Disk read error ! " db 0Dh, 0Ah, 0 ; 21/03/2022 - Retro UNIX 386 v1.2 runix_p_bs: ; get retro unix v2 partition's boot sector address ; 09/05/2021 ; 19/04/2021 - Retro UNIX 386 v2 ; INPUT: ; ;;Masterboot buffer at offset mbrbuf ; ; 21/03/2022 ; esi = Masterboot buffer (data) address ; OUTPUT: ; ;;esi = start sector addr of retro unix v2 fs ; ; 21/03/2022 ; eax = start sector address of retro unix v2 fs ; ; cf = 1 -> error, retro unix fs not found ; (eax = 0) ; ; Modified registers: esi, eax ptBootable equ 0 ptBeginHead equ 1 ptBeginSector equ 2 ptBeginCylinder equ 3 ptFileSystemID equ 4 ptEndHead equ 5 ptEndSector equ 6 ptEndCylinder equ 7 ptStartSector equ 8 ptSectors equ 12 FS_RETROUNIX equ 71h ; runix v2 partition ID ;cmp word [mbrbuf+510], 0AA55h cmp word [esi+510], 0AA55h jne short runix_p_nf ; partition table entries are at offset 1BEh ;mov esi, mbrbuf+1BEh+ptFileSystemID add esi, 1BEh+ptFileSystemID lea eax, [esi+(4*16)] runix_p_bs_0: cmp byte [esi], FS_RETROUNIX ; 71h je short runix_p_f ; it is retro unix partition add esi, 16 ;cmp esi, mbrbuf+1BEh+ptFileSystemID+(4*16) cmp esi, eax jb short runix_p_bs_0 runix_p_nf: sub eax, eax ; eax = 0 stc retn runix_p_f: ;mov esi, [esi+ptStartSector-ptFileSystemID] mov eax, [esi+ptStartSector-ptFileSystemID] retn ; 23/10/2015 com1_irq4: dd dummy_retn com2_irq3: dd dummy_retn dummy_retn: retn