Mercurial > hg > Members > kono > nitros9-code
view level1/modules/boot_1773.asm @ 1882:c96f594fe098
Added fragmented boot support... needs additional testing.
| author | boisy |
|---|---|
| date | Tue, 11 Oct 2005 11:10:25 +0000 |
| parents | 1e026af2217c |
| children | b151cc54904e |
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******************************************************************** * Boot - WD1773 Boot module * * $Id$ * * Edt/Rev YYYY/MM/DD Modified by * Comment * ------------------------------------------------------------------ * 4 1985/??/?? * Original Tandy distribution version. * * 6 1998/10/12 Boisy G. Pitre * Obtained from L2 Upgrade archive, has 6ms step rate and disk timeout * changes. * * 6r2 2003/05/18 Boisy G. Pitre * Added '.' output for each sector for OS-9 L2 and NitrOS9 for * Mark Marlette (a special request :). * * 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 * * 7 2005/10/10 Boisy G. Pitre * Added fragmented bootfile support nam Boot ttl WD1773 Boot module IFP1 use defsfile ENDC * 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 DRVSEL2 equ %00000100 DRVSEL1 equ %00000010 DRVSEL0 equ %00000001 * Default Boot is from drive 0 BootDr set DRVSEL0 IFEQ DNum-1 BootDr set DRVSEL1 Alternate boot from drive 1 ENDC IFEQ DNum-2 BootDr set DRVSEL2 Alternate boot from drive 2 ENDC IFEQ DNum-3 BootDr set SIDESEL Alternate boot from drive 3 ENDC * 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 * Sector Size SECTSIZE equ 256 * Step Rates: * $00 = 6ms * $01 = 12ms * $02 = 20ms * $03 = 30ms STEP set $00 tylg set Systm+Objct atrv set ReEnt+rev rev set $00 edition set 7 mod eom,name,tylg,atrv,start,size * NOTE: these are U-stack offsets, not DP seglist rmb 2 pointer to segment list blockloc rmb 2 pointer to memory requested blockimg rmb 2 duplicate of the above bootloc rmb 3 sector pointer; not byte pointer bootsize rmb 2 size in bytes drvsel rmb 1 currtrak rmb 1 ddtks rmb 1 no. of sectors per track dblsided rmb 1 side rmb 1 side 2 flag size equ . name fcs /Boot/ fcb edition start orcc #IntMasks ensure IRQs are off (necessary?) leas -size,s tfr s,u get pointer to data area pshs u save pointer to data area * Device Specific Init lbsr HWInit * bcs error2 * Request memory for LSN0 ldd #256 get sector/fd buffer os9 F$SRqMem get it! bcs error2 bsr getpntr restore U to point to our statics * Read LSN0 clrb MSB sector ldx #0 LSW sector lbsr HWRead read LSN 0 bcs error branch if error ifgt Level-1 lda #'0 --- loaded in LSN0' jsr <D.BtBug --- endc * Pull relevant values from LSN0 lda DD.TKS,x number of tracks on this disk sta ddtks,u lda DD.FMT,x disk format byte sta dblsided,u lda DD.BT,x os9boot pointer sta bootloc,u ldd DD.BT+1,x LSW of 24 bit address std bootloc+1,u ldd DD.BSZ,x os9boot size in bytes std bootsize,u beq FragBoot if zero, do frag boot * Old style boot -- make a fake FD segment leax FD.SEG,x addd #$00FF round up to next page exg a,b std FDSL.B,x save file size lda bootloc,u sta FDSL.A,x ldd bootloc+1,u std FDSL.A+1,x save LSN of file (contiguous) clr FDSL.S,x make next segment entry 0 clr FDSL.S+1,x clr FDSL.S+2,x ldd bootsize,u bra GrabBootMem Back2Krn ldx blockimg,u pointer to start of os9boot in memory clrb clear carry ldd bootsize,u error2 leas 2+size,s reset the stack same as PULS U rts return to kernel * Error point - return allocated memory and then return to kernel error * Return memory allocated for sector buffers ldd #256 ldu blockloc,u os9 F$SRtMem bra error2 * Routine to save off alloced mem from F$SRqMem into blockloc,u and restore * the statics pointer in U getpntr tfr u,d save pointer to requested memory ldu 2,s recover pointer to data stack std blockloc,u ret rts * NEW! Fragmented boot support! FragBoot ldb bootloc,u MSB fd sector location ldx bootloc+1,u LSW fd sector location lbsr HWRead get fd sector ldd FD.SIZ+2,x get file size (we skip first two bytes) std bootsize,u leax FD.SEG,x point to segment table GrabBootMem ifgt Level-1 os9 F$BtMem else os9 F$SRqMem endc bcs error bsr getpntr std blockimg,u * Get os9boot into memory BootLoop stx seglist,u update segment list ldb FDSL.A,x MSB sector location BL2 ldx FDSL.A+1,x LSW sector location bne BL3 tstb beq Back2Krn BL3 lbsr HWRead inc blockloc,u point to next input sector in mem ifgt Level-1 lda #'. Show .' jsr <D.BtBug endc ldx seglist,u get pointer to segment list dec FDSL.B+1,x get segment size beq NextSeg if <=0, get next segment ldd FDSL.A+1,x update sector location by one to 24bit word addd #1 std FDSL.A+1,x ldb FDSL.A,x adcb #0 stb FDSL.A,x bra BL2 NextSeg leax FDSL.S,x advance to next segment entry bra BootLoop ************************************************************ ************************************************************ * Hardware-Specific Booter Area * ************************************************************ ************************************************************ * Device Specific Init * HWInit - Initialize the device HWInit ldy Address,pcr get hardware address lda #%11010000 ($D0) Force Interrupt (stops any command in progress) sta CMDREG,y write command to command register lbsr Delay2 delay 54~ lda STATREG,y clear status register lda #$FF sta currtrak,u set current track to 255 leax >NMIRtn,pcr point to NMI routine IFGT Level-1 stx <D.NMI save address ELSE stx >D.XNMI+1 save address lda #$7E sta >D.XNMI ENDC lda #MOTON+BootDr turn on drive motor sta CONTROL,y * MOTOR ON spin-up delay loop (~307 mSec) IFGT Level-1 ldd #50000 ELSE ldd #25000 ENDC IFNE H6309 nop ENDC L003A nop nop IFNE H6309 nop nop nop ENDC subd #$0001 bne L003A rts 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 #0+STEP RESTORE cmd lbra L0195 * * HWRead - Read a 256 byte sector from the device * Entry: Y = hardware address * B = bits 23-16 of LSN * X = bits 15-0 of LSN * blockloc,u = ptr to 256 byte sector * Exit: X = ptr to data (i.e. ptr in blockloc,u) * * Read a sector from the 1773 * Entry: B,X = LSN to read HWRead lda #$91 bsr L00DF else branch subroutine bcs L00D6 branch if error ldx blockloc,u get buffer pointer in X for caller clrb L00D6 rts L00D7 bcc L00DF pshs x,b,a bsr L00B7 puls x,b,a L00DF pshs x,b,a save LSN, command bsr L00EA puls x,b,a restore LSN, command bcc L00D6 branch if OK lsra bne L00D7 L00EA bsr L013C bcs L00D6 if error, return to caller ldx blockloc,u get address of buffer to fill orcc #IntMasks mask interrupts pshs x save X ldx #$FFFF ldb #%10000000 ($80) READ SECTOR command stb CMDREG,y write to command register 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 set side 2 bit L0107 stb CONTROL,y lbsr Delay2 delay 54~ orb #HALTENA HALT enable ($80) * lda #%00000010 RESTORE cmd ($02) *L0111 bita >DPort+STATREG * bne L0123 * leay -$01,y * bne L0111 * lda drvsel,u * sta >DPort+CONTROL * puls y * bra L0138 stb CONTROL,y nop nop * bra L0123 ldx ,s get X saved earlier * Sector READ Loop L0123 lda DATAREG,y read from WD DATA register sta ,x+ * stb >DPort+CONTROL nop bra L0123 * RVH NOTE: This ONLY works for double density boot disks! The Tandy * controllers internally gate HALT enable with the DDEN bit, which * means that reading a single-density boot disk will not generate the * NMI signal needed to exit the read loop! Single-density disks must * use a polled I/O loop instead. NMIRtn leas R$Size,s adjust stack puls x ldb STATREG,y read WD STATUS register bitb #$9C any errors? * bitb #$04 LOST DATA bit set? beq RetOK branch if not * beq ChkErr branch if not L0138 comb else we will return error ldb #E$Read RetOK rts L013C lda #MOTON+BootDr permit alternate drives sta drvsel,u save byte to static mem clr side,u start on side 1 tfr x,d cmpd #$0000 beq L016C clr ,-s clear space on stack tst dblsided,u double sided disk? beq L0162 branch if not bra L0158 * Double-sided code L0152 com side,u flag side 2 bne L0158 inc ,s L0158 subb ddtks,u sbca #$00 bcc L0152 bra L0168 L0160 inc ,s L0162 subb ddtks,u sbca #$00 bcc L0160 L0168 addb #18 add sectors per track puls a get current track indicator off of stack L016C incb stb SECTREG,y save in sector register L0170 ldb currtrak,u get current track in B stb TRACKREG,y save in track register cmpa currtrak,u same as A? beq L018D branch if so sta currtrak,u sta DATAREG,y ldb #$10+STEP SEEK command bsr L0195 send command to controller pshs x * Seek Delay ldx #$222E delay ~39 mSec (78mS L1) L0187 leax -$01,x bne L0187 puls x L018D clrb rts *ChkErr bitb #$98 evaluate WD status (READY, RNF, CRC err) * bne L0138 * clrb * rts L0195 bsr L01A8 issue FDC cmd, wait 54~ L0197 ldb STATREG,y bitb #$01 still BUSY? bne L0197 loop until command completes rts * Entry: B = command byte L019F lda drvsel,u sta CONTROL,y stb CMDREG,y 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 * 54 clock delay including bsr (=30uS/L2,60us/L1) Delay2 IFNE H6309 nop nop ENDC lbsr Delay3 Delay3 IFNE H6309 nop nop ENDC lbsr Delay4 Delay4 IFNE H6309 nop ENDC rts IFGT Level-1 * Filler to get $1D0 Filler fill $39,$1D0-3-2-1-* ENDC Address fdb DPort WhichDrv fcb 0 emod eom equ * end