Mercurial > hg > Members > kono > nitros9-code
view level1/modules/boot_ide.asm @ 3047:a951ab0b3003
level1 6309: Switch to native mode early in rel.asm
Otherwise it will crash in the first F$Link call.
| author | Robert Gault <robert.gault@att.net> |
|---|---|
| date | Sat, 24 Jan 2015 23:15:55 +0100 |
| parents | 17d43fd29ee2 |
| children | c0bb75b72339 |
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******************************************************************** * Boot - IDE Boot Module * * $Id$ * * Edt/Rev YYYY/MM/DD Modified by * Comment * ------------------------------------------------------------------ * ? 1994/06/25 Alan DeKok * Diassembled. * * 6 1999/08/17 Paul T. Barton * Redone for IDE. * * 7 2002/06/27 Boisy G. Pitre * Added use of LSN bits 23-16. * * 7r1 2004/05/12 Boisy G. Pitre * Optimized, made toG wait on !BUSY and DRDY, added slowdown POKE * for Fujitsu 128MB CF (may be temporary) * * 8 2004/07/29 Boisy G. Pitre * Now detects CHS/LBA mode to work with ALL IDE drives. * * 9 2005/10/13 Boisy G. Pitre * Support for fragmented bootfiles added. NAM Boot TTL IDE Boot Module IFP1 USE defsfile USE ide.d ENDC tylg SET Systm+Objct atrv SET ReEnt+rev rev SET $00 edition SET 9 * Disassembled 94/06/25 11:37:47 by Alan DeKok * ReDone by Paul T. Barton 99/08/17, for IDE MOD eom,name,tylg,atrv,start,size * on-stack static storage ORG 0 cyls RMB 2 sides RMB 1 sects RMB 2 mode RMB 1 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 LSN0Ptr RMB 2 LSN0 pointer (used by boot_common.asm) size EQU . name FCS /Boot/ FCB edition * Common booter-required defines LSN24BIT EQU 1 FLOPPY EQU 0 USE boot_common.asm * HWInit - Initialize the device * Entry: Y = hardware address * Exit: Carry Clear = OK, Set = Error * B = error (Carry Set) HWInit ldb Address+2,pcr bne slave@ lda #%10100000 FCB $8C slave@ lda #%10110000 sta mode,u stb DevHead,y select device a@ tst Status,y wait for BSY to clear bmi a@ lda #$EC sta Command,y b@ tst Status,y bmi b@ * Harvest C/H/S values. ldb DataReg,y ignore bytes 0-1 ldb DataReg,y bytes 2-3 = no. of cylinders lda Latch,y std cyls,u save cylinders in our private static area ldb DataReg,y ignore bytes 4-5 ldb DataReg,y bytes 6-7 = no. of heads stb sides,u save sides on stack (B) ldb DataReg,y ignore bytes 8-9 ldb DataReg,y ignore bytes 10-11 ldb DataReg,y bytes 12-13 = no. of sectors/track lda Latch,y std sects,u save sectors/track on stack (Y) * Throw away the next 42 (48-7) words ldb #43 l@ tst DataReg,y lda Latch,y decb bne l@ * A holds byte with LBA bit anda #%00000010 LBA drive? beq nope@ ldb mode,u orb #%01000000 stb mode,u nope@ ldb #256-50 o@ tst DataReg,y decb bne o@ HWTerm clrb rts * 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) HWRead pshs x,b b@ tst Status,y bmi b@ if =1 then loop lda mode,u sta DevHead,y 0L0d/0hhh device=CHS r@ ldb Status,y is IDE ready for commands? andb #BusyBit+DrdyBit ready ? cmpb #DrdyBit bne r@ loop until Drdy=1 and Busy=0 ldb #$01 only one at a time stb SectCnt,y only one at a time anda #%01000000 beq chs@ branch if mode lda ,s get bits 23-16 sta CylHigh,y ldd 1,s get bits 15-0 stb SectNum,y sta CylLow,y bra DoCmd chs@ * Compute proper C:H:S value lda sides,u get device's head ldb sects+1,u and sector mul multiply H*S * Note, there is a chance here that if the product is zero, we could loop forever * beq ZeroProd pshs d save product of H*S ldd 1+2,s get bits 15-0 of LSN ldx #-1 start Y at -1 inc 0+2,s increment physical sector * Here we are doing physLSN/(H*S) to get cylinder for physLSN a@ leax 1,x increment count to compensate subd ,s subtract (H*S) from physLSN bhs a@ if D>=0 then continue dec 0+2,s decrement phys sector bits 23-16 bne a@ if not zero, continue divide addd ,s++ add in (H*S) to make non-negative pshs d X now holds cylinder, save D on stack tfr x,d exg a,b swap std CylLow,y store computed cylinder in HW puls d restore saved cylinder * Now we will compute the sector/head value ldx #-1 c@ leax 1,x subb sects+1,u sbca #0 bcc c@ addb sects+1,u incb add 1 to B, which is sector stb SectNum,y store computed sector in HW tfr x,d orb DevHead,y OR in with value written earlier stb DevHead,y DoCmd lda #S$READ read one sector sta Command,y finish process Blk2 lda Status,y is IDE ready to send? anda #DrqBit DRQ, data request beq Blk2 loop while DRQ =0 ldx blockloc,u clr ,s BlkLp lda DataReg,y A <- IDE ldb Latch,y std ,x++ into RAM inc ,s bpl BlkLp go get the rest b@ lda DataReg,y read remaining 256 bytes dec ,s bne b@ leax -256,x stx 1,s lda Status,y check for error-bit clrb puls b,x,pc * ------------------------------------------ *Init * pshs d,y * ldy <Address,pcr * bsr ChkBusy could be spinning up... * lda #Diagnos hits all drives * sta Command,y ./ * bsr ChkBusy wait 'til both done * clrb no errors * puls d,y,pc * Entry: A = number to show * Destroys D *Num * tfr a,b * lsra * lsra * lsra * lsra * bsr x@ * andb #$0F * tfr b,a *x@ * adda #'0 * cmpa #'9 * ble s@ * adda #$7 *s@ jsr <D.BtBug * rts IFGT Level-1 Pad FILL $39,$1D0-3-2-1-* ENDC Address FDB SDAddr WhchDriv FCB 0 Drive to use (0 = master, 1 = slave) EMOD eom EQU * END