Mercurial > hg > Members > kono > nitros9-code
changeset 1520:5ff76789bec2
Updated boot_1773.asm from Rodney H.
sysgo.asm startup time now reflects release date.
| author | boisy |
|---|---|
| date | Tue, 17 Feb 2004 22:46:06 +0000 |
| parents | e54480a359e4 |
| children | cc5c8ad073a6 |
| files | level1/modules/boot_1773.asm level1/modules/sysgo.asm |
| diffstat | 2 files changed, 106 insertions(+), 105 deletions(-) [+] |
line wrap: on
line diff
--- a/level1/modules/boot_1773.asm Sun Feb 15 16:33:24 2004 +0000 +++ b/level1/modules/boot_1773.asm Tue Feb 17 22:46:06 2004 +0000 @@ -19,6 +19,9 @@ * * 6r3 2003/08/31 Robert Gault * Put BLOB-stop code in place, changed orb #$30 to orb #$28 +* +* 6r4 2004/02/17 Rodney Hamilton +* Minor optimizations, improvements in source comments nam Boot ttl WD1773 Boot module @@ -28,17 +31,23 @@ use rbfdefs ENDC -* Drive select bits at $FF40 -SIDESEL equ %01000000 -DRVSEL2 equ %00100000 +* FDC Control Register bits at $FF40 +HALTENA equ %10000000 +SIDESEL equ %01000000 DRVSEL3 if no DS drives +DDEN equ %00100000 +READY equ %00010000 READY for Tandy WD1773-based controllers MOTON equ %00001000 -PRECOMP equ %00000100 +DRVSEL2 equ %00000100 DRVSEL1 equ %00000010 DRVSEL0 equ %00000001 -* WD17x3 Definitions -CMDREG equ 8+0 -STATREG equ CMDREG +* Default Boot Drive is /d0 +BootDr set DRVSEL0 + +* WD17x3 DPort offsets +CONTROL equ 0 +CMDREG equ 8+0 write-only +STATREG equ CMDREG read-only TRACKREG equ 8+1 SECTREG equ 8+2 DATAREG equ 8+3 @@ -46,27 +55,21 @@ * Sector Size SECTSIZE equ 256 - -* Step Rate: -* $00 = 6ms -* $01 = -* $02 = -* $03 = 30ms +* Step Rates: +* $00 = 6ms +* $01 = 12ms +* $02 = 20ms +* $03 = 30ms STEP set $00 -*Drive value & number -* $01 = 0 -* $02 = 1 -* $03 = 2 -BootDr set $01 - tylg set Systm+Objct atrv set ReEnt+rev -rev set $03 +rev set $04 edition set 6 mod eom,name,tylg,atrv,start,size +* NOTE: these are U-stack offsets, not DP drvsel rmb 1 buffptr rmb 2 currtrak rmb 1 @@ -74,7 +77,7 @@ ddtks rmb 1 no. of sectors per track *ddtot rmb 1 dblsided rmb 1 -side rmb 1 +side rmb 1 side 2 flag size equ . name fcs /Boot/ @@ -89,10 +92,10 @@ tfr s,u put 'stack statics' in U * ldx #DPort lda #%11010000 ($D0) Force Interrupt (stops any command in progress) - sta DPort+CMDREG write command to command register + sta >DPort+CMDREG write command to command register * sta CMDREG,x write command to command register - lbsr Delay2 delay a bit - lda DPort+STATREG read status register + lbsr Delay2 delay 54~ + lda >DPort+STATREG clear status register * lda STATREG,x read status register lda #$FF sta currtrak,u set current track to 255 @@ -105,13 +108,13 @@ sta >D.XNMI ENDC lda #MOTON+BootDr turn on drive motor - sta >DPort + sta >DPort+CONTROL -* delay loop to allow disk to spin up +* MOTOR ON spin-up delay loop (~307 mSec) IFGT Level-1 - ldd #$C350 + ldd #50000 ELSE - ldd #$61A8 + ldd #25000 ENDC IFNE H6309 nop @@ -144,51 +147,52 @@ * From LSN0, we get various pieces of info. * ldd DD.TOT+1,y * std ddtot,u - lda <DD.FMT,y get format byte of LSN0 -* sta ddfmt,u save it for ??? - anda #FMT.SIDE keep side bit - sta dblsided,u and save it - lda DD.TKS,y get sectors per track - sta ddtks,u and save - ldd <DD.BSZ,y get bootfile size - std ,s save on stack - ldx <DD.BT+1,y get start sector of bootfile - pshs x push on the stack - ldd #SECTSIZE load D with sector size - ldu buffptr,u and point to the buffer pointer - os9 F$SRtMem return the memory - ldd $02,s get the bootfile size + lda <DD.FMT,y get format byte of LSN0 +* sta ddfmt,u save it for ??? + anda #FMT.SIDE keep side bit + sta dblsided,u and save it + lda DD.TKS,y get sectors per track + sta ddtks,u and save + ldd <DD.BSZ,y get bootfile size + std ,s save on stack + ldx <DD.BT+1,y get start sector of bootfile + pshs x push on the stack + ldd #SECTSIZE load D with sector size + ldu buffptr,u and point to the buffer pointer + os9 F$SRtMem return the memory + ldd $02,s get the bootfile size IFGT Level-1 os9 F$BtMem ELSE - os9 F$SRqMem get the memory from the system + os9 F$SRqMem get the memory from the system ENDC - puls x pull bootfile start sector off stack - bcs L00AA branch if error - stu $02,s save pointer to bootfile mem on stack - tfr u,d transfer to D for later store - ldu $06,s restore original U -* ldd $02,s get pointer to bootfile mem - std buffptr,u and save pointer - ldd ,s get bootfile size - beq L00A3 branch if zero + puls x pull bootfile start sector off stack + bcs L00AA branch if error + stu 2,s save pointer to bootfile mem on stack + stu 8+buffptr,s also save to buffptr,u + ldu 6,s reload original U +* ldd 2,s get pointer to bootfile mem +* std buffptr,u and save pointer + ldd ,s get bootfile size + beq L00A3 branch if zero * this loop reads a sector at a time from the bootfile * X = start sector * D = bootfile size -L0091 pshs x,b,a save params +L0091 pshs x,b,a save params clrb - bsr ReadSect read sector - bcs L00A8 branch if error + bsr ReadSect read sector + bcs L00A8 branch if error IFGT Level-1 - lda #'. dump out a period for boot debugging - jsr <D.BtBug do the debug stuff + lda #'. dump out a period for boot debugging + jsr <D.BtBug do the debug stuff ENDC - puls x,b,a get params - inc buffptr,u point to next 256 bytes - leax 1,x move to next sector - subd #SECTSIZE subtract sector bytes from size - bhi L0091 continue if more space + puls x,b,a restore params +* RVH NOTE: the next 3 lines assume sector size=256=LSN size? + inc buffptr,u point to next 256 bytes + leax 1,x move to next sector + subd #SECTSIZE subtract sector bytes from size + bhi L0091 continue if more space L00A3 clrb puls b,a bra L00AC @@ -196,15 +200,15 @@ L00AA leas $02,s L00AC puls u,y,x leas size,s clean up stack - clr >DPort shut off floppy disk + clr >DPort+CONTROL shut off floppy disk rts -L00B7 lda #DRVSEL2+MOTON+BootDr permit alternate drives +L00B7 lda #DDEN+MOTON+BootDr permit alternate drives sta drvsel,u save drive selection byte clr currtrak,u clear current track lda #$05 lbsr L0170 - ldb #STEP + ldb #0+STEP RESTORE cmd lbra L0195 * Read a sector from the 1773 @@ -224,7 +228,7 @@ puls x,b,a L00DF pshs x,b,a save LSN, command bsr L00EA - puls x,b,a get LSN, command + puls x,b,a restore LSN, command bcc L00D6 branch if OK lsra bne L00D7 @@ -236,35 +240,27 @@ ldy #$FFFF ldb #%10000000 ($80) READ SECTOR command stb >DPort+CMDREG write to command register - ldb drvsel,u -* Notes on the next line: -* The byte in question comes after telling the controller that it should -* read a sector. RegB is then loaded (ldb drvsel,u) which means it is set to $29 -* (%00101001) or the default boot drive if sub L00B7 has been run. At this -* point an orb #$30 or orb #%00110000 means that write precomp and double -* density flags are or'd in. This does not make any sense at all for a -* read command. I suppose the command may not even be needed but $28 just -* ensures that motor on and double density are set. -* orb #$28 was $30 which RG thinks is an error -* 09/02/03: Futher investigation shows that the OS-9 Level One Booter will -* FAIL if orb #$28 is used. It does not fail if orb #$30 is used. ???? - orb #$30 RG thinks is an error - tst side,u + ldb drvsel,u (DDEN+MOTORON+BootDr) +* NOTE: The 1773 FDC multiplexes the write precomp enable and ready +* signals on the ENP/RDY pin, so the READY bit must always be ON for +* read and seek commands. (from the FD502 FDC Service Manual) + orb #DDEN+READY set DDEN+READY bits ($30) + tst side,u are we on side 2? beq L0107 - orb #SIDESEL -L0107 stb >DPort - lbsr Delay2 - orb #$80 -* lda #%00000010 ($02) RESTORE + orb #SIDESEL set side 2 bit +L0107 stb >DPort+CONTROL + lbsr Delay2 delay 54~ + orb #HALTENA HALT enable ($80) +* lda #%00000010 RESTORE cmd ($02) *L0111 bita >DPort+STATREG * bne L0123 * leay -$01,y * bne L0111 * lda drvsel,u -* sta >DPort +* sta >DPort+CONTROL * puls y * bra L0138 - stb >DPort + stb >DPort+CONTROL nop nop bra L0123 @@ -272,9 +268,14 @@ * Sector READ Loop L0123 lda >DPort+DATAREG read from WD DATA register sta ,x+ -* stb >DPort +* stb >DPort+CONTROL nop bra L0123 +* RVH NOTE: This ONLY works for double density boot disks! The Tandy +* controllers internally gate HALT enable with the DDEN bit, which +* means that reading a single-density boot disk will not generate the +* NMI signal needed to exit the read loop! Single-density disks must +* use a polled I/O loop instead. NMIRtn leas R$Size,s adjust stack puls y @@ -289,16 +290,16 @@ L013C lda #MOTON+BootDr permit alternate drives sta drvsel,u save byte to static mem - clr side,u assume side 0 + clr side,u start on side 1 tfr x,d cmpd #$0000 beq L016C clr ,-s clear space on stack - tst dblsided,u disk double sided? + tst dblsided,u double sided disk? beq L0162 branch if not bra L0158 * Double-sided code -L0152 com side,u +L0152 com side,u flag side 2 bne L0158 inc ,s L0158 subb ddtks,u @@ -315,15 +316,15 @@ stb >DPort+SECTREG save in sector register L0170 ldb currtrak,u get current track in B stb >DPort+TRACKREG save in track register - cmpa currtrak,u same as A + cmpa currtrak,u same as A? beq L018D branch if so sta currtrak,u sta >DPort+DATAREG ldb #$10+STEP SEEK command bsr L0195 send command to controller pshs x -* Delay - ldx #$222E +* Seek Delay + ldx #$222E delay ~39 mSec (78mS L1) L0187 leax -$01,x bne L0187 puls x @@ -335,24 +336,25 @@ * clrb * rts -L0195 bsr Delay1 +L0195 bsr L01A8 issue FDC cmd, wait 54~ L0197 ldb >DPort+STATREG - bitb #$01 - bne L0197 + bitb #$01 still BUSY? + bne L0197 loop until command completes rts * Entry: B = command byte L019F lda drvsel,u - sta >DPort + sta >DPort+CONTROL stb >DPort+CMDREG rts +* issue command and wait 54 clocks +* Controller requires a min delay of 14uS (DD) or 28uS (SD) +* following a command write before status register is valid +L01A8 + bsr L019F * Delay branches -Delay1 - IFNE H6309 - nop - ENDC - bsr L019F +* 54 clock delay including bsr (=30uS/L2,60us/L1) Delay2 IFNE H6309 nop @@ -379,4 +381,3 @@ emod eom equ * end -