Mercurial > hg > Members > kono > nitros9-code
annotate 3rdparty/booters/boot_rampak.asm @ 459:3e3f1f79ba00
Sources now use 'fill' pseudo-op to fill out for L2 modules
| author | boisy |
|---|---|
| date | Thu, 26 Sep 2002 15:25:14 +0000 |
| parents | df43967d6a46 |
| children |
| rev | line source |
|---|---|
| 45 | 1 ******************************************************************** |
| 392 | 2 * Boot - Disto RAMPak Boot Module |
| 45 | 3 * |
| 4 * $Id$ | |
| 5 * | |
| 6 * Ed. Comments Who YY/MM/DD | |
| 7 * ------------------------------------------------------------------ | |
| 8 * 5 Created ADK | |
| 9 * 6 Fixed small bugs, improved speed BGP 98/10/20 | |
| 10 | |
| 11 nam Boot | |
| 392 | 12 ttl Disto RAMPak Boot Module |
| 45 | 13 |
| 14 * Disassembled 94/06/25 11:37:47 by Alan DeKok | |
| 15 | |
| 16 ifp1 | |
| 17 use defsfile | |
| 18 endc | |
| 19 | |
| 20 tylg set Systm+Objct | |
| 21 atrv set ReEnt+rev | |
| 22 rev set $00 | |
| 23 edition set 6 | |
| 24 | |
| 25 mod eom,name,tylg,atrv,start,size | |
| 26 | |
| 27 * on-stack buffer to use | |
| 28 org 0 | |
| 29 size equ . | |
| 30 | |
| 31 name equ * | |
| 32 fcs /Boot/ | |
| 33 fcb edition | |
| 34 | |
| 35 start orcc #IntMasks ensure IRQ's are off. | |
| 36 | |
| 37 pshs x,d save 4 bytes of junk | |
| 38 R.D equ 1 | |
| 39 R.X equ 3 | |
| 40 | |
| 41 lda >MPI.Slct get current slot | |
| 42 pshs a save off | |
| 43 lda >PakSlot,pcr get multipak slot number | |
| 44 bmi cont if >127, invalid slot number | |
| 45 anda #$03 force it to be legal | |
| 46 ldb #$11 | |
| 47 mul put it into both nibbles | |
| 48 stb >MPI.Slct go to the desired slot | |
| 49 | |
| 50 cont ldd #$0001 request one byte (will round up to 1 page) | |
| 51 os9 F$SRqMem request the memory | |
| 52 bcs L00AE exit on error | |
| 53 * U is implicitely the buffer address to use | |
| 54 | |
| 55 ldx #$0000 X=0: got to sector #$0000 | |
| 56 bsr GetSect load in LSN0, and point Y to the buffer | |
| 57 bcs L00AE | |
| 58 | |
| 59 ldd <DD.BSZ,u size of the bootstrap file | |
| 60 std R.D,s save it on the stack (0,s is junk) | |
| 61 ldx <DD.BT+1,u get starting sector of the bootstrap file | |
| 62 | |
| 63 pshs x save the starting sector number | |
| 64 ldd #$0100 one page of memory | |
| 65 os9 F$SRtMem return the copy of LSN0 to free memory | |
| 66 | |
| 67 ldd R.X,s get size of boot memory to request | |
| 279 | 68 ifgt Level-1 |
| 45 | 69 os9 F$BtMem ask for the boot memory |
| 279 | 70 else |
| 71 os9 F$SRqMem ask for the boot memory | |
| 72 endc | |
| 45 | 73 puls x restore the starting sector number |
| 74 bcs L00AE no memory: exit with error | |
| 75 | |
| 76 stu R.X,s save start address of memory allocated | |
| 77 std R.D,s and the size of the boot memory | |
| 78 beq L00A7 if no memory allocated, exit | |
| 79 | |
| 80 SectLp pshs x,d save sector #, size of boot | |
| 81 bsr GetSect read one sector | |
| 82 bcs L00AC if there's an error, exit | |
| 83 puls x,d restor sector, size of boot | |
| 84 | |
| 85 leau $0100,u go up one page in memory | |
| 86 leax $01,x go to the next sector | |
| 87 subd #$0100 take out one sector, need value in B, too. | |
| 88 bhi SectLp loop until all sectors are read | |
| 89 | |
| 90 L00A7 puls a | |
| 91 sta >MPI.Slct | |
| 92 clrb clear carry | |
| 93 puls d return size of boot memory to user | |
| 94 bra L00B0 and go exit | |
| 95 | |
| 96 L00AC leas $04,s remove X,D off of stack | |
| 97 L00AE puls a | |
| 98 sta >MPI.Slct | |
| 99 leas $02,s kill D off of the stack | |
| 100 | |
| 101 L00B0 puls x restore start address of memory allocated | |
| 102 * leas size,s remove the on-stack buffer | |
| 279 | 103 clr >DPort stop the disk |
| 45 | 104 L00BA rts |
| 105 | |
| 106 * GetSect: read a sector off of the disk | |
| 107 * Entry: X = sector number to read | |
| 108 GetSect pshs d,x,y | |
| 109 ldy >Address,pcr grab the device address | |
| 110 tfr x,d move 16 bit LSN into 2 8-bit registers | |
| 111 sta 2,y save HB LSN | |
| 112 stb 1,y save LB LSN | |
| 113 leax ,u get buffer address to write into | |
| 114 clrb and start out at byte zero | |
| 115 | |
| 116 ReadLp stb ,y save byte number | |
| 117 lda 3,y grab the byte | |
| 118 sta ,x+ save in the buffer | |
| 119 incb go to the enxt byte | |
| 120 bne ReadLp | |
| 121 clrb no errors | |
| 122 puls d,x,y,pc restore registers and return | |
| 123 | |
| 279 | 124 ifgt Level-1 |
|
459
3e3f1f79ba00
Sources now use 'fill' pseudo-op to fill out for L2 modules
boisy
parents:
392
diff
changeset
|
125 Pad fill $39,$1D0-6-* |
| 279 | 126 endc |
| 45 | 127 |
| 128 Address fdb $FF40 address of the device to boot from | |
| 129 PakSlot fcb $01 multipak slot number | |
| 130 | |
| 131 emod | |
| 132 eom equ * | |
| 133 end |