@ -106,7 +106,7 @@ bid_cur .equ -1 ; used below to indicate current bank
;
start:
ld sp , bl _stack ; setup private stack
call DELAY_INIT ; init delay functions
call delay_init ; init delay functions
;
; Disable interrupts if IM1 is active because we are switching to page
; zero in user bank and it has not been prepared with IM1 vector yet.
@ -456,7 +456,7 @@ setcon:
ld hl , str_newcon ; new console msg
call pstr ; print string on cur console
pop af ; restore new console unit
call PRTDECB ; print unit num
call prtdecb ; print unit num
;
; Set console unit
ld b , BF_SYSPOKE ; HBIOS func: POKE
@ -479,7 +479,7 @@ setcon:
reboot:
ld hl , str_reboot ; point to message
call pstr ; print it
call LDELAY ; wait for message to display
call ldelay ; wait for message to display
;
# if ( BIOS = = BIOS_WBW )
;
@ -618,11 +618,11 @@ diskboot:
ld hl , str_boot1
call pstr
ld a ,( bootunit )
call PRTDECB
call prtdecb
ld hl , str_boot2
call pstr
ld a ,( bootslice )
call PRTDECB
call prtdecb
;
# if ( DS KYENABLE )
ld hl , msg_load ; point to load message
@ -632,13 +632,21 @@ diskboot:
# if ( BIOS = = BIOS_WBW )
;
; Check that drive actually exists
ld c , a
;ld c,a ; put in C for func call
ld b , BF_SYSGET ; HBIOS func: sys get
ld c , BF_SYSGET_DIOCNT ; HBIOS sub-func: disk count
rst 08 ; do it, E=disk count
ld a ,( bootunit ) ; get boot disk unit
cp e ; compare to count
jp nc , err_nodisk ; handle no disk err
;
; Sense media
ld a ,( bootunit ) ; get boot disk unit
ld c , a ; put in C for func call
ld b , BF_DIOMEDIA ; HBIOS func: media
ld e , 1 ; enable media check/discovery
rst 08 ; do it
jp nz , err_diskio ; handle error
;
; If non-zero slice requested, confirm device can handle it
ld a ,( bootslice ) ; get slice
@ -652,40 +660,6 @@ diskboot:
cp DI ODEV_IDE ; IDE is max slice device type
jp c , err_noslice ; no such slice, handle err
;
diskboot1:
; Sense media
ld a ,( bootunit ) ; get boot disk unit
ld c , a ; put in C for func call
ld b , BF_DIOMEDIA ; HBIOS func: media
ld e , 1 ; enable media check/discovery
rst 08 ; do it
jp nz , err_diskio ; handle error
call pdot ; show progress
;
; Seek to boot info sector, third sector
ld a ,( bootslice ) ; get boot slice
ld e , a ; move to E for mult
ld h , 65 ; 65 tracks per slice
call MULT8 ; hl := h * e
ld de , $ 0002 ; head 0, sector 2
ld b , BF_DIOSEEK ; HBIOS func: seek
ld a ,( bootunit ) ; get boot disk unit
ld c , a ; put in C
rst 08 ; do it
jp nz , err_diskio ; handle error
call pdot ; show progress
;
; Read sector into local buffer
ld b , BF_DIOREAD ; HBIOS func: disk read
ld a ,( bootunit ) ; get boot disk unit
ld c , a ; put in C for func call
ld hl , bl _infosec ; read into info sec buffer
ld d , BID_USR ; user bank
ld e , 1 ; transfer one sector
rst 08 ; do it
jp nz , err_diskio ; handle error
call pdot ; show progress
;
# endif
;
# if ( BIOS = = BIOS_UNA )
@ -712,12 +686,67 @@ diskboot1:
jr z , di skboot1 ; if so, OK
jp err_noslice ; no such slice, handle err
;
# endif
;
diskboot1:
; Initialize working LBA value
ld hl , 0 ; zero HL
ld ( lba ), hl ; init
ld ( lba + 2 ), hl ; ... LBA
;
; Set legacy sectors per slice
ld hl , 16640 ; legacy sectors per slice
ld ( sp s ), hl ; save it
;
; Attempt to read MBR
ld de , 0 ; MBR is at
ld hl , 0 ; ... first sector
ld bc , bl _mbrsec ; read into MBR buffer
ld ( dma ), bc ; save
ld b , 1 ; one sector
ld a ,( bootunit ) ; get bootunit
ld c , a ; put in C
call di skread ; do it
ret nz ; abort on error
;
; Check signature
ld hl ,( bl _mbrsec + $ 1 FE ) ; get signature
ld a , l ; first byte
cp $ 55 ; should be $55
jr nz , di skboot1c ; if not, no part table
ld a , h ; second byte
cp $ AA ; should be $AA
jr nz , di skboot1c ; if not, no part table
;
; Try to find our entry in part table and capture lba offset
ld b , 4 ; four entries in part table
ld hl , bl _mbrsec + $ 1B E + 4 ; offset of first entry part type
diskboot1a:
ld a ,( hl ) ; get part type
cp $ 52 ; cp/m partition?
jr z , di skboot1b ; cool, grab the lba offset
ld de , 16 ; part table entry size
add hl , de ; bump to next entry part type
djnz di skboot1a ; loop thru table
jr di skboot1c ; too bad, no cp/m partition
;
diskboot1b:
; Capture the starting LBA of the CP/M partition we found
ld de , 4 ; LBA is 4 bytes after part type
add hl , de ; point to it
ld de , lba ; loc to store lba offset
ld bc , 4 ; 4 bytes (32 bits)
ldir ; copy it
; If boot from partition, use new sectors per slice value
ld hl , 16384 ; new sectors per slice
ld ( sp s ), hl ; save it
;
diskboot1c:
; Add slice offset
ld a ,( bootslice ) ; get boot slice, A is loop cnt
ld hl , 0 ; DE:HL is LBA
ld de , 0 ; ... initialize to zero
ld bc , 16640 ; sectors per slice
ld hl ,( lba ) ; set DE:HL
ld de ,( lba + 2 ) ; ... to starting LBA
ld bc ,( sp s ) ; sectors per slice
diskboot2:
or a ; set flags to check loop ctr
jr z , di skboot4 ; done if counter exhausted
@ -729,30 +758,30 @@ diskboot3:
jr di skboot2 ; and loop
;
diskboot4:
ld ( loadl ba ), hl ; sav e lba, low word
ld ( loadl ba + 2 ), de ; sav e lba, high word
ld ( lba ), hl ; updat e lba, low word
ld ( lba + 2 ), de ; updat e lba, high word
;
; Seek to boot info sector, third sector
push hl ; save HL
ld hl , str_ldsec ; display prefix
call pstr ; do it
pop hl ; restore HL
call prthex32 ; display starting sector
call pdot ; show progress
;
; Read boot info sector, third sector
ld bc , 2 ; sector offset
add hl , bc ; add to LBA value low word
jr nc , di skboot5 ; check for carry
inc de ; if so, bump high word
diskboot5:
ld a ,( bootunit ) ; get disk unit to boot
ld b , a ; put in B for func call
ld c , $ 41 ; UNA func: set lba
rst 08 ; set lba
jp nz , err_api ; handle error
ld bc , bl _infosec ; read buffer
ld ( dma ), bc ; save
ld a ,( bootunit ) ; disk unit to read
ld c , a ; put in C
ld b , 1 ; one sector
call di skread ; do it
ret nz ; abort on error
call pdot ; show progress
;
; Read sector into local buffer
ld c , $ 42 ; UNA func: read sectors
ld de , bl _infosec ; dest of cpm image
ld l , 1 ; sectors to read
rst 08 ; do read
jp nz , err_diskio ; handle error
;
# endif
;
; Check signature
ld de ,( bb_sig ) ; get signature read
@ -762,6 +791,7 @@ diskboot5:
ld a , $ 5 A ; expected value of second byte
cp e ; compare
jp nz , err_sig ; handle error
call pdot ; show progress
;
; Print disk boot info
; Volume "xxxxxxx" (0xXXXX-0xXXXX, entry @ 0xXXXX)
@ -774,17 +804,17 @@ diskboot5:
call pstr ; print
push hl ; save string ptr
ld bc ,( bb_cpmloc ) ; get load loc
call PRTHEXWORD ; print it
call prthexword ; print it
pop hl ; restore string ptr
call pstr ; print
push hl ; save string ptr
ld bc ,( bb_cpmend ) ; get load end
call PRTHEXWORD ; print it
call prthexword ; print it
pop hl ; restore string ptr
call pstr ; print
push hl ; save string ptr
ld bc ,( bb_cpment ) ; get load end
call PRTHEXWORD ; print it
call prthexword ; print it
pop hl ; restore string ptr
call pstr ; print
;
@ -798,19 +828,25 @@ diskboot5:
ld ( loadcnt ), a ; ... and save it
call pdot ; show progress
;
# if ( BIOS = = BIOS_WBW )
;
; Load image into memory
ld b , BF_DIOREAD ; HBIOS func: read sectors
; Start OS load at sector 3
ld hl ,( lba ) ; low word of saved LBA
ld de ,( lba + 2 ) ; high word of saved LBA
ld bc , 3 ; offset for sector 3
add hl , bc ; apply it
jr nc , di skboot6 ; check for carry
inc de ; bump high word if so
diskboot6:
ld bc ,( bb_cpmloc ) ; load address
ld ( dma ), bc ; and save it
ld a ,( loadcnt ) ; get sectors to read
ld b , a ; put in B
ld a ,( bootunit ) ; get boot disk unit
ld c , a ; put in C
ld hl ,( bb_cpmloc ) ; load address
ld d , BID_USR ; user bank
ld a ,( loadcnt ) ; get sectors to read
ld e , a ; number of sectors to load
rst 08 ; do it
jp nz , err_diskio ; handle errors
call di skread ; read image
ret nz ; abort on error
call pdot ; show progress
;
# if ( BIOS = = BIOS_WBW )
;
; Record boot unit/slice
ld b , BF_SYSSET ; hb func: set hbios parameter
@ -823,36 +859,10 @@ diskboot5:
ld e , a ; save in E
rst 08
jp nz , err_api ; handle errors
call pdot ; show progress
;
# endif
;
# if ( BIOS = = BIOS_UNA )
;
; Start os load at sector 3
ld hl ,( loadlba ) ; low word of saved LBA
ld de ,( loadlba + 2 ) ; high word of saved LBA
ld bc , 3 ; offset for sector 3
add hl , bc ; apply it
jr nc , di skboot6 ; check for carry
inc de ; bump high word if so
diskboot6:
ld c , $ 41 ; UNA func: set lba
ld a ,( bootunit ) ; get boot disk unit
ld b , a ; move to B
rst 08 ; set lba
jp nz , err_api ; handle error
;
; Read OS image into memory
ld c , $ 42 ; UNA func: read sectors
ld a ,( bootunit ) ; get boot disk unit
ld b , a ; move to B
ld de ,( bb_cpmloc ) ; dest of cpm image
ld a ,( loadcnt ) ; get sectors to read
ld l , a ; sectors to read
rst 08 ; do read
jp nz , err_diskio ; handle error
call pdot ; show progress
;
; Record boot unit/slice
; UNA provides only a single byte to record the boot unit
@ -876,6 +886,8 @@ diskboot6:
call pdot ; show progress
;
# endif
;
call pdot ; show progress
;
# if ( DS KYENABLE )
ld hl , msg_go ; point to go message
@ -886,6 +898,55 @@ diskboot6:
ld hl ,( bb_cpment ) ; get entry vector
jp ( hl ) ; and go there
;
; Read disk sector(s)
; DE:HL is LBA, B is sector count, C is disk unit
;
diskread:
;
# if ( BIOS = = BIOS_UNA )
;
; Seek to requested sector in DE:HL
push bc ; save unit and count
ld b , c ; unit to read in B
ld c , $ 41 ; UNA func: set lba
rst 08 ; set lba
pop bc ; recover unit and count
jp nz , err_api ; handle error
;
; Read sector(s) into buffer
ld l , b ; sectors to read
ld b , c ; unit to read in B
ld c , $ 42 ; UNA func: read sectors
ld de ,( dma ) ; dest for read
rst 08 ; do read
jp nz , err_diskio ; handle error
xor a ; signal success
ret ; and done
;
# endif
;
# if ( BIOS = = BIOS_WBW )
;
; Seek to requested sector in DE:HL
push bc ; save unit & count
set 7 , d ; set LBA access flag
ld b , BF_DIOSEEK ; HBIOS func: seek
rst 08 ; do it
pop bc ; recover unit & count
jp nz , err_diskio ; handle error
;
; Read sector(s) into buffer
ld e , b ; transfer count
ld b , BF_DIOREAD ; HBIOS func: disk read
ld hl ,( dma ) ; read into info sec buffer
ld d , BID_USR ; user bank
rst 08 ; do it
jp nz , err_diskio ; handle error
xor a ; signal success
ret ; and done
;
# endif
;
;=======================================================================
; Utility functions
;=======================================================================
@ -1079,6 +1140,269 @@ isnum1:
or $ FF ; set NZ
ret ; and done
;
; Delay 16us (cpu speed compensated) incuding call/ret invocation
; Register A and flags destroyed
; No compensation for z180 memory wait states
; There is an overhead of 3ts per invocation
; Impact of overhead diminishes as cpu speed increases
;
; cpu scaler (cpuscl) = (cpuhmz - 2) for 16us + 3ts delay
; note: cpuscl must be >= 1!
;
; example: 8mhz cpu (delay goal is 16us)
; loop = ((6 * 16) - 5) = 91ts
; total cost = (91 + 40) = 131ts
; actual delay = (131 / 8) = 16.375us
;
; --- total cost = (loop cost + 40) ts -----------------+
delay: ; 17ts (from invoking call) |
ld a ,( cpuscl ) ; 13ts |
; |
delay1: ; |
; --- loop = ((cpuscl * 16) - 5) ts ------------+ |
dec a ; 4ts | |
# if ( BIOS = = BIOS_WBW ) ; | |
# if ( CPUFAM = = CPU_Z180 ) ; | |
or a ; +4ts for z180 | |
# endif ; | |
# endif ; | |
jr nz , delay1 ; 12ts (nz) / 7ts (z) | |
; ----------------------------------------------+ |
; |
ret ; 10ts (return) |
;-------------------------------------------------------+
;
; Delay 16us * DE (cpu speed compensated)
; Register DE, A, and flags destroyed
; No compensation for z180 memory wait states
; There is a 27ts overhead for call/ret per invocation
; Impact of overhead diminishes as DE and/or cpu speed increases
;
; cpu scaler (cpuscl) = (cpuhmz - 2) for 16us outer loop cost
; note: cpuscl must be > 0!
;
; Example: 8MHz cpu, DE=6250 (delay goal is .1 sec or 100,000us)
; inner loop = ((16 * 6) - 5) = 91ts
; outer loop = ((91 + 37) * 6250) = 800,000ts
; actual delay = ((800,000 + 27) / 8) = 100,003us
;
; --- total cost = (outer loop + 27) ts ------------------------+
vdelay: ; 17ts (from invoking call) |
; |
; --- outer loop = ((inner loop + 37) * de) ts ---------+ |
ld a ,( cpuscl ) ; 13ts | |
; | |
vdelay1: ; | |
; --- inner loop = ((cpuscl * 16) - 5) ts ------+ | |
# if ( BIOS = = BIOS_WBW ) ; | | |
# if ( CPUFAM = = CPU_Z180 ) ; | | |
or a ; +4ts for z180 | | |
# endif ; | | |
# endif ; | | |
dec a ; 4ts | | |
jr nz , vdelay1 ; 12ts (nz) / 7ts (z) | | |
; ----------------------------------------------+ | |
; | |
dec de ; 6ts | |
# if ( BIOS = = BIOS_WBW ) ; | | |
# if ( CPUFAM = = CPU_Z180 ) ; | |
or a ; +4ts for z180 | |
# endif ; | |
# endif ; | |
ld a , d ; 4ts | |
or e ; 4ts | |
jp nz , vdelay ; 10ts | |
;-------------------------------------------------------+ |
; |
ret ; 10ts (final return) |
;---------------------------------------------------------------+
;
; Delay about 0.5 seconds
; 500000us / 16us = 31250
;
ldelay:
push af
push de
ld de , 31250
call vdelay
pop de
pop af
ret
;
; Initialize delay scaler based on operating cpu speed
; HBIOS *must* be installed and available via rst 8!!!
; CPU scaler := max(1, (phimhz - 2))
;
delay_init:
# if ( BIOS = = BIOS_UNA )
ld c , $ F8 ; UNA bios get phi function
rst 08 ; returns speed in hz in de:hl
ld b , 4 ; divide mhz in de:hl by 100000h
delay_init0:
srl d ; ... to get approx cpu speed in
rr e ; ...mhz. throw away hl, and
djnz delay_init0 ; ...right shift de by 4.
inc e ; fix up for value truncation
ld a , e ; put in a
# else
ld b , BF_SYSGET ; HBIOS func=get sys info
ld c , BF_SYSGET_CPUINFO ; HBIOS subfunc=get cpu info
rst 08 ; call HBIOS, rst 08 not yet installed
ld a , l ; put speed in mhz in accum
# endif
cp 3 ; test for <= 2 (special handling)
jr c , delay_init1 ; if <= 2, special processing
sub 2 ; adjust as required by delay functions
jr delay_init2 ; and continue
delay_init1:
ld a , 1 ; use the min value of 1
delay_init2:
ld ( cpuscl ), a ; update cpu scaler value
ret
# if ( CPUMHZ < 3 )
cpu scl .db 1 ; cpu scaler must be > 0
# else
cpu scl .db CPUMHZ - 2 ; otherwise 2 less than phi mhz
# endif
;
; Print value of a in decimal with leading zero suppression
;
prtdecb:
push hl
push af
ld l , a
ld h , 0
call prtdec
pop af
pop hl
ret
;
; Print value of HL in decimal with leading zero suppression
;
prtdec:
push bc
push de
push hl
ld e , '0'
ld bc , - 10000
call prtdec1
ld bc , - 1000
call prtdec1
ld bc , - 100
call prtdec1
ld c , - 10
call prtdec1
ld e , 0
ld c , - 1
call prtdec1
pop hl
pop de
pop bc
ret
prtdec1:
ld a , '0' - 1
prtdec2:
inc a
add hl , bc
jr c , prtdec2
sbc hl , bc
cp e
jr z , prtdec3
ld e , 0
call cout
prtdec3:
ret
;
; Short delay functions. No clock speed compensation, so they
; will run longer on slower systems. The number indicates the
; number of call/ret invocations. A single call/ret is
; 27 t-states on a z80, 25 t-states on a z180.
;
; ; z80 z180
; ; ---- ----
dly64: call dl y32 ; 1728 1600
dly32: call dl y16 ; 864 800
dly16: call dl y8 ; 432 400
dly8: call dl y4 ; 216 200
dly4: call dl y2 ; 108 100
dly2: call dl y1 ; 54 50
dly1: ret ; 27 25
;
; Add hl,a
;
; A register is destroyed!
;
addhla:
add a , l
ld l , a
ret nc
inc h
ret
;
; Print the hex byte value in A
;
prthexbyte:
push af
push de
call hexascii
ld a , d
call cout
ld a , e
call cout
pop de
pop af
ret
;
; Print the hex word value in BC
;
prthexword:
push af
ld a , b
call prthexbyte
ld a , c
call prthexbyte
pop af
ret
;
; Print the hex dword value in DE:HL
;
prthex32:
push bc
push de
pop bc
call prthexword
push hl
pop bc
call prthexword
pop bc
ret
;
; Convert binary value in A to ASCII hex characters in DE
;
hexascii:
ld d , a
call hexconv
ld e , a
ld a , d
rlca
rlca
rlca
rlca
call hexconv
ld d , a
ret
;
; Convert low nibble of A to ASCII hex
;
hexconv:
and 0Fh ; low nibble only
add a , 90h
daa
adc a , 40h
daa
ret
;
;=======================================================================
; Console character I/O helper routines (registers preserved)
;=======================================================================
@ -1241,7 +1565,7 @@ prtall1:
ld hl , str_disk ; prefix string
call pstr ; display it
ld a , c ; index
call PRTDECB ; print it
call prtdecb ; print it
ld hl , str_on ; separator string
call pstr
push bc ; save loop control
@ -1268,7 +1592,7 @@ prtdrv:
and $ 0 F ; isolate device bits
add a , a ; multiple by two for word table
ld hl , devtbl ; point to start of table
call ADDHLA ; add A to HL for table entry
call addhla ; add A to HL for table entry
ld a ,( hl ) ; deref HL for string adr
inc hl ; ...
ld h ,( hl ) ; ...
@ -1277,7 +1601,7 @@ prtdrv:
pop hl ; recover HL
pop de ; recover DE
ld a , e ; device number
call PRTDECB ; print it
call prtdecb ; print it
ld a , ':' ; suffix
call cout ; print it
ret
@ -1340,7 +1664,7 @@ prtdrv:
ld hl , str_disk ; prefix string
call pstr ; display it
ld a , b ; index
call PRTDECB ; print it
call prtdecb ; print it
ld a , ' ' ; formatting
call cout ; do it
ld a , '=' ; formatting
@ -1380,7 +1704,7 @@ prtdrv2: ; print device
pop bc ; recover unit
call pstr ; print device name
ld a , b ; unit to a
call PRTDECB ; print it
call prtdecb ; print it
ld a , ':' ; device name suffix
call cout ; print it
ret ; done
@ -1452,10 +1776,12 @@ str_err_api .db "Unexpected hardware BIOS API failure",0
;=======================================================================
;
# define USEDELAY
# include "util.asm"
; #include "util.asm"
;
# if ( DS KYENABLE )
# define DS KY_KBD
VDELAY .equ vdelay
DLY2 .equ dl y2
# include "dsky.asm"
# endif
;
@ -1492,6 +1818,7 @@ str_binfo2 .db $22," [0x",0
str_binfo3 .db "-0x" , 0
str_binfo4 .db ", entry @ 0x" , 0
str_binfo5 .db "]" , 0
str_ldsec .db ", Sector 0x" , 0
;
str_help .db "\r\n"
.db "\r\n L - List ROM Applications"
@ -1651,9 +1978,12 @@ bid_ldr .ds 1 ; bank at startup
# endif
# if ( BIOS = = BIOS_UNA )
bid_ldr .ds 2 ; bank at startup
loadlba .ds 4 ; lba for load, dword
# endif
;
lba .ds 4 ; lba for load, dword
dma .ds 2 ; address for load
sps .ds 2 ; sectors per slice
;
ra_tbl_loc .ds 2 ; points to active ra_tbl
bootunit .ds 1 ; boot disk unit
bootslice .ds 1 ; boot disk slice
@ -1685,5 +2015,11 @@ bb_biloc .ds 2 ; loc to patch boot drive info
bb_cpmloc .ds 2 ; final ram dest for cpm/cbios
bb_cpmend .ds 2 ; end address for load
bb_cpment .ds 2 ; CP/M entry point (cbios boot)
;
;
; Master Boot Record sector is read into area below.
;
bl_mbrsec .equ $
.ds 512
;
.end
Wayne Warthen
6 years ago