Updated DOSGEN

Updated DOSGEN to create FAT images in memory instead of copying everything to the system area.
This commit is contained in:
Broken Pipe
2024-03-27 13:54:35 +00:00
parent ff2d9aff6a
commit 1c9241610a
4 changed files with 322 additions and 39 deletions
Binary file not shown.
+316 -33
View File
@@ -1,10 +1,29 @@
; DOSGEN The SYSGEN for 86-DOS version 1.00
; DOSGEN The SYSGEN for 86-DOS version 1.10
; by Broken Pipe
; Runs on the Z80 under CP/M
;
; Disk Format Parameters
;
SECSIZ: EQU 128 ;128 bytes per sector
SPT: EQU 26 ;26 sectors per track
SYSTRK: EQU 2 ;2 system tracks
SYSTRK: EQU 2 ;2 tracks for just system
NEWTRK: EQU 4 ;4 tracks for new disk
CLSSIZ: EQU 4 ;4 records per cluster
;
; File System Parameters
;
OBOOT: EQU 0 ;Sector 0
OBIOS: EQU 128 ;Sector 1
ODOS: EQU 1152 ;Sector 9
OFAT1: EQU 6656 ;Sector 52
OFAT2: EQU 7424 ;Sector 58
ODIR: EQU 8192 ;Sector 64
OUSER: EQU 9216 ;Sector 72
FATSIZ: EQU OFAT2-OFAT1 ;FAT size in bytes
DIRSIZ: EQU OUSER-ODIR ;Directory size in bytes
;
; BIOS call offsets.
@@ -36,6 +55,9 @@ S1: EQU 13
S2: EQU 14
RC: EQU 15
;
; Program entry point.
;
ORG 100H
LD SP,STACK ;Setup new stack
@@ -49,18 +71,13 @@ RC: EQU 15
JR EXIT
DRVOK: DEC A ;Convert to actual drive number
LD (DRIVE),A
CALL SETSYS ;Setup system area
LD IX,BRCFCB ;Load boot record FCB
CALL FOPEN ;Open it
LD HL,PBOOT ;Set DMA to boot record in memory
CALL FREAD ;Read it
LD A,(FCB2+1) ;Get first char of second param
OR 20H ;Convert to lower case
CP 't' ;Temp disk?
JR Z,TMPIO ;Yes, use TMPBIO.COM for BIOS
LD IX,BIOFCB ;Load BIOS FCB
JR OPENIO
TMPIO: LD IX,TIOFCB ;Load temp BIOS FCB
OPENIO: CALL FOPEN ;Open it
CALL FOPEN ;Open it
LD HL,PBIOS ;Set DMA to BIOS in memory
CALL FREAD ;Read it
LD IX,DOSFCB ;Load DOS FCB
@@ -69,12 +86,13 @@ OPENIO: CALL FOPEN ;Open it
CALL FREAD ;Read it
LD A,(FCB2+1) ;Get first char of second param
OR 20H ;Convert to lower case
CP 't' ;Temp disk?
JR NZ,SKIP ;No, skip writing TMPCMD.COM
LD IX,CMDFCB ;Load CMD FCB
CALL FOPEN ;Open it
LD HL,PCMD ;Set DMA to CMD in memory
CALL FREAD ;Read it
CP 'n' ;New disk?
JR NZ,SKIP ;No, skip writing file system
CALL SETFAT ;Setup FAT image
LD IX,CMDFCB ;Load COMMAND FCB
CALL ADDFIL ;Add it to FAT and directory
LD IX,RDCFCB ;Load RDCPM FCB
CALL ADDFIL ;Add it to FAT and directory
SKIP: CALL WRTSYS ;Write system in memory to disk
LD DE,DONE ;Fall through to EXIT
@@ -93,6 +111,47 @@ EXIT:
CALL BDOS
JP 0
;
; Sets up the system area in memory. AF, BC, DE and HL destroyed.
;
SETSYS:
LD HL,PBOOT ;Fill system area with 0
LD DE,PBOOT+1
LD BC,PFAT1-PBOOT-1
LD (HL),0
LDIR
LD A,SYSTRK ;Set track count to SYSTRK
LD (NUMTRK),A
RET
;
; Sets up a FAT image after the system area. AF, BC, DE and HL
; destroyed.
;
SETFAT:
LD HL,PFAT1 ;Fill FATs with 0
LD DE,PFAT1+1
LD BC,FATSIZ+FATSIZ-1
LD (HL),0
LDIR
LD HL,PDIR ;Fill directory with 0E5H
LD DE,PDIR+1
LD BC,DIRSIZ-1
LD (HL),0E5H
LDIR
LD HL,0 ;Set current cluster to 0
LD (CURCLS),HL
LD HL,PDIR ;Set current directory entry
LD (CURDIR),HL
LD HL,PUSER ;Set current data pointer
LD (CURPTR),HL
LD A,NEWTRK ;Set track count to NEWTRK
LD (NUMTRK),A
LD DE,0FFFH ;Write the first 2 FAT entries
CALL PUTCLS
CALL PUTCLS
RET
;
; Opens a file with its FCB in IX. IX preserved, all other
; registers destroyed. Does not return if the requested file
@@ -123,20 +182,24 @@ FOPEN:
LD C,WRITESTR
CALL BDOS ;Print it
LD DE,OPENER
JR EXIT ;Exit with last part of the message.
JP EXIT ;Exit with last part of the message.
;
; Reads all records of a file pointed to by its FCB in IX to
; the DMA in HL. IX preserved, all other registers destroyed.
; Does not return if reading fails.
; Reads all records of a file pointed to by its FCB in IX to the
; DMA address in HL. IX preserved, all other registers destroyed.
; Does not return if reading fails. Returns number of records
; read in BC.
;
FREAD:
PUSH HL
LD IY,0 ;Set record count to 0
RDLOOP: PUSH HL
POP DE ;DE points to DMA
LD C,DMAOFF
PUSH IX ;Save registers
PUSH HL
PUSH IY
CALL BDOS ;Set DMA before reading
POP IY
POP HL ;Restore registers
POP IX
LDREC: LD C,READ
@@ -144,15 +207,27 @@ LDREC: LD C,READ
POP DE
PUSH IX ;Save registers
PUSH HL
PUSH IY
CALL BDOS ;Read a record
POP IY
POP HL ;Restore registers
POP IX
CP 0 ;Success?
JR NZ,CHKEND ;No, check if EOF
INC IY ;Increment record count
LD DE,128
ADD HL,DE ;Increment DMA by 128 bytes
JR FREAD ;Read next record
CHKEND: CP 1 ;EOF?
JR RDLOOP ;Read next record
CHKEND: PUSH AF ;Save AF
PUSH IX ;Save IX
PUSH IY ;Save record count
LD C,DMAOFF
LD DE,80H
CALL BDOS ;Reset DMA to default
POP BC ;Restore record count to BC
POP IX ;Restore IX
POP AF ;Restore AF
CP 1 ;EOF?
RET Z ;Yes, done
LD DE,RFAIL
LD C,WRITESTR
@@ -168,6 +243,207 @@ CHKEND: CP 1 ;EOF?
LD DE,RDERR
JP EXIT ;Exit with last part of the message.
;
; Multiplies BC by DE and returns the result in HL. AF and BC destroyed.
;
MLTPLY:
LD A,B
LD B,16
MLOOP: ADD HL,HL
SLA C
RLA
JR NC,MNOADD
ADD HL,DE
MNOADD: DJNZ MLOOP
RET
;
; Divides BC by DE and returns the result in BC, with remainder in HL.
; AF and BC destroyed.
;
DIVIDE:
LD HL,0
LD A,B
LD B,8
DIVLP1: RLA
ADC HL,HL
SBC HL,DE
JR NC,DNADD1
ADD HL,DE
DNADD1: DJNZ DIVLP1
RLA
CPL
LD B,A
LD A,C
LD C,B
LD B,8
DIVLP2: RLA
ADC HL,HL
SBC HL,DE
JR NC,DNADD2
ADD HL,DE
DNADD2: DJNZ DIVLP2
RLA
CPL
LD B,C
LD C,A
RET
;
; Writes the lowest 12 bits of DE to the BCth entry of the FAT pointed
; to by HL. AF and HL destroyed.
;
FATPUT:
PUSH BC ;Save registers
PUSH DE
LD A,D ;Make DE a 12-bit number
AND 0FH
LD D,A
BIT 0,C ;Is cluster even?
PUSH AF ;Save flags
ADD HL,BC ;HL = HL + BC * 1.5
SRL B
RR C
ADD HL,BC
POP AF ;Restore flags
JR Z,NOTODD ;Jump if even
LD A,(HL) ;Odd, get byte at HL
AND 0FH ;Clear high bits
PUSH HL ;Save HL
LD H,D ;Shift DE by 4 bits
LD L,E
ADD HL,HL
ADD HL,HL
ADD HL,HL
ADD HL,HL
LD D,H
LD E,L
POP HL ;Restore HL
OR E ;Combine with high bits of E
LD (HL),A ;Save it back
INC HL ;Point to next byte
LD (HL),D ;Save high byte of DE
JR PUTDON ;Done, pop registers and return
NOTODD: LD (HL),E ;Even, save low byte of DE
INC HL ;Point to next byte
LD A,(HL) ;Get byte at HL
AND 0F0H ;Clear low 4 bits
OR D ;Combine with high byte of DE
LD (HL),A ;Save it back
PUTDON: POP DE ;Restore registers
POP BC
RET
;
; Writes the lowest 12 bits of DE to next entry of the FATs at
; PFAT1 and PFAT2. AF, BC and HL destroyed. (CURCLS) automatically
; incremented.
;
PUTCLS:
LD HL,PFAT1
LD BC,(CURCLS)
CALL FATPUT
LD HL,PFAT2
CALL FATPUT
INC BC
LD (CURCLS),BC
RET
;
; Converts the record count in BC to cluster count. AF and HL
; destroyed.
;
RECTOCLS:
LD HL,CLSSIZ-1 ;Add CLSSIZ-1
ADD HL,BC
LD B,H
LD C,L
LD DE,CLSSIZ
CALL DIVIDE ;Divide by CLSSIZ
RET
;
; Adds a file pointed to by its FCB in IX to the system FAT image.
; All registers destroyed. Does not return of the file cannopt be
; opened and read. (CURCLS), (CURDIR) and (CURPTR) automatically
; incremented.
;
ADDFIL:
CALL FOPEN ;Open the file
LD HL,(CURPTR) ;Set DMA to current file location
CALL FREAD ;Read it
PUSH BC ;Save record count
CALL RECTOCLS ;Convert to number of clusters
PUSH BC ;Save cluster count
LD H,B ;Multiply by 128
LD L,C
XOR A
SRL H
RR L
RRA
LD H,L
LD L,A
LD B,H ;Multiply by CLSSIZ for bytes
LD C,L
LD DE,CLSSIZ
CALL MLTPLY
LD BC,(CURPTR) ;Load current data pointer
ADD HL,BC ;Add size and pointer
LD (CURPTR),HL ;Save new data pointer
POP BC ;Restore cluster count
LD H,B ;Save cluster count to HL
LD L,C
LD DE,(CURCLS) ;Load current cluster
PUSH DE ;Save as starting cluster
FATLP: OR A ;Decrement cluster count
LD DE,1
SBC HL,DE
JR Z,LSTCLS ;Handle last cluster if 0
JP M,EMPTY ;Handle empty file if negative
LD DE,(CURCLS) ;Get current cluster
INC DE ;Next cluster = current + 1
PUSH HL
CALL PUTCLS ;Write FAT entry
POP HL
JR FATLP ;Go to next cluster
LSTCLS: LD DE,0FFFH ;Load end-of-chain value
CALL PUTCLS ;Write FAT entry
JR WRTDIR ;Go write directory entry
EMPTY: POP DE ;Discard saved starting cluster
LD DE,0 ;Save 0 as new starting cluster
PUSH DE
WRTDIR: LD DE,(CURDIR) ;Load pointer to current dir entry
PUSH IX
POP HL ;HL points to FCB
INC HL ;Increment to point to file name
LD BC,11 ;11 characters to copy
LDIR ;Copy file name over
POP HL ;Restore starting cluster number
LD A,L ;Write it to directory entry
LD (DE),A
INC DE
LD A,H
LD (DE),A
INC DE
POP HL ;Restore record count
XOR A ;Multiply by 128 to get file size
SRL H
RR L
RRA
LD H,L
LD L,A
LD A,L ;Write file size
LD (DE),A
INC DE
LD A,H
LD (DE),A
INC DE
XOR A ;Write 0 for high byte of file size
LD (DE),A
INC DE
LD (CURDIR),DE ;Update current directory pointer
RET
;
; BIOS drive select routine, drive in C. All registers destroyed.
;
@@ -214,7 +490,7 @@ DWRITE:
JP (HL)
;
; Writes the system in memory at LOADP to the first SYSTRK tracks of
; Writes the system in memory at LOADP to the first (NUMTRK) tracks of
; the disk in (DRIVE). All registers destroyed.
;
WRTSYS:
@@ -227,8 +503,8 @@ WRTSYS:
LD (TRACK),A
WRTTRK: LD HL,TRACK
INC (HL) ;Next track
LD A,SYSTRK ;Number of system tracks
CP (HL) ;All system tracks done?
LD A,(NUMTRK) ;Number of tracks to write
CP (HL) ;All tracks done?
RET Z ;Yes, system transfer complete
LD C,(HL)
CALL TRK ;Set track number
@@ -275,11 +551,11 @@ WRTER: DB 'Disk write error',13,10,'$'
DONE: DB 'System transfered',13,10,'$'
;
; FCBs of system files. Open these from bottom to top, one at a time.
; FCBs. Open these from bottom to top, one at a time.
;
CMDFCB: DB 0,'TMPCMD COM'
RDCFCB: DB 0,'RDCPM COM'
CMDFCB: DB 0,'COMMAND COM'
DOSFCB: DB 0,'86DOS COM'
TIOFCB: DB 0,'TMPBIO COM'
BIOFCB: DB 0,'DOSIO COM'
BRCFCB: DB 0,'BOOT COM'
DS 24
@@ -293,6 +569,10 @@ TRACK: DS 1
SECTOR: DS 1
DMADDR: DS 2
RETRY: DS 1
CURCLS: DS 2
CURDIR: DS 2
CURPTR: DS 2
NUMTRK: DS 1
;
; Stack of 128 bytes.
@@ -305,8 +585,11 @@ STACK:
; components.
;
LOADP:
PBOOT: EQU $ ;Relative offset of BOOT (0 * 128)
PBIOS: EQU $+128 ;Relative offset of BIOS (1 * 128)
PDOS: EQU $+1152 ;Relative offset of 86DOS (9 * 128)
PCMD: EQU $+4480 ;Relative offset of TMPCMD (35 * 128)

PBOOT: EQU $+OBOOT ;Relative offset of BOOT
PBIOS: EQU $+OBIOS ;Relative offset of BIOS
PDOS: EQU $+ODOS ;Relative offset of 86-DOS
PFAT1: EQU $+OFAT1 ;Relative offset of FAT 1
PFAT2: EQU $+OFAT2 ;Relative offset of FAT 2
PDIR: EQU $+ODIR ;Relative offset of directory
PUSER: EQU $+OUSER ;Relative offset of user area

+4 -4
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@@ -51,7 +51,7 @@ This assembler can only produce Intel HEX files for object code, therefore you m
## DOSGEN
This is a tool I wrote to copy 86-DOS system files to the system area of IBM 8" SSSD floppies. It works in a similar way to CP/M's <code>SYSGEN</code> utility.
DOSGEN takes the following parameters: <code>[x:]DOSGEN y: [T]</code>
DOSGEN takes the following parameters: <code>[x:]DOSGEN y: [N]</code>
where
@@ -70,10 +70,10 @@ where
<td>is a disk drive specifier indicating the disk upon which the 86-DOS system is to be written.</td>
</tr>
<tr>
<td><code>T</code></td>
<td>is an optional switch indicating that a temporary copy of the system is to be used. A temporary system includes a temporary BIOS and a temporary command interpreter. Normally, the BIOS uses DOS to load the command interpreter, <code>COMMAND.COM</code>, from the file area. The temporary BIOS loads the command interpreter directly from the system area. This is useful when 86-DOS is being built and deployed for the first time, as the command interpreter cannot be put into the file area without a working copy of DOS, and a working copy of DOS needs the command interpreter. The temporary command interpreter differs from the normal command interpreter in that it includes <code>RDCPM</code> as an internal command. This is needed for copying the actual command interpreter from CP/M disks to DOS disks once the temporary system is booted.</td>
<td><code>N</code></td>
<td>is an optional switch indicating that a new file system is to be put on the destination disk. If this switch is specified, a file system with the files <code>COMMAND.COM</code> and <code>RDCPM.COM</code> will be written alongside the system.</td>
</tr>
</tbody>
</table>
To copy 86-DOS to a new floppy disk, you must have the files <code>BOOT.COM</code>, <code>DOSIO.COM</code> and <code>86DOS.COM</code> on the current drive. If a temporary system is to be copied, <code>TMPBIO.COM</code> and <code>TMPCMD.COM</code> must also exist.
To copy 86-DOS to a new floppy disk, you must have the files <code>BOOT.COM</code>, <code>DOSIO.COM</code> and <code>86DOS.COM</code> on the current drive. If a new file system is to be created, <code>COMMAND.COM</code> and <code>RDCPM.COM</code> must also exist.
+2 -2
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@@ -107,7 +107,7 @@ ENUMDIR:
ADD SI,19 ;Point to next entry
DEC BX
JS DONE
CMP SI,SECBUF
CMP SI,DIRBUF+128
JB ENUMDIR
INC AX
JP READDIR
@@ -257,4 +257,4 @@ CPMTAB2:
DW 0,0,0,0
DW 0,0,0,0
DW 0,0,0,0