Mercurial > hg > Members > kono > nitros9-code
annotate level2/modules/rammer.asm @ 1631:ec6fb5543b22
Robert Gault's modifications for correcting timing errors
| author | boisy |
|---|---|
| date | Mon, 12 Jul 2004 01:38:08 +0000 |
| parents | 46c68f878889 |
| children | f77ac3ae8a43 |
| rev | line source |
|---|---|
| 732 | 1 ******************************************************************** |
|
1424
32f1dae476b7
Fixed references in source from OS-9 to NitrOS-9 where appropriate
boisy
parents:
1348
diff
changeset
|
2 * Rammer - NitrOS-9 Level 2 RAM Disk |
| 732 | 3 * |
| 4 * $Id$ | |
| 5 * | |
| 6 * Alan DeKok's version of RAMMER - Based on original Keving Darling version | |
| 7 * | |
| 8 * NOTE: For some reason, when DEINIZing /r0, the INIT routine gets called... | |
| 9 * but it still deallocates memory! | |
| 1348 | 10 * |
| 11 * Edt/Rev YYYY/MM/DD Modified by | |
| 12 * Comment | |
| 13 * ------------------------------------------------------------------ | |
| 14 * 4 ????/??/?? ??? | |
| 15 * Original Kevin Darling Version. | |
| 16 * | |
| 17 * 5 2000/03/14 L. Curtis Boyle | |
| 18 * Several changes | |
| 19 * | |
| 20 * 5r2 2000/05/09 L. Curtis Boyle | |
| 21 * Allowed driver to go past 400K, attempted some fixes for handling /MD, | |
| 22 * so that setting vfy=0 on /R0 would not completely crash the system. | |
| 23 * Fixed some error reporting bugs that would crash the system, and | |
| 24 * moved entry table to between READ/WRITE to allow short branches to both. | |
| 25 | |
| 732 | 26 |
| 27 * Following CAN be set higher, but will take another page of system RAM then. | |
| 28 * 200 will allow maximum of 1,638,400 byte RAM drive. | |
| 29 MAXBLOCK set 201 Maximum # of MMU blocks allowed in RAM drive | |
| 30 | |
| 31 nam Rammer | |
|
1424
32f1dae476b7
Fixed references in source from OS-9 to NitrOS-9 where appropriate
boisy
parents:
1348
diff
changeset
|
32 ttl NitrOS-9 Level 2 RAM Disk |
| 732 | 33 |
| 34 ifp1 | |
| 35 use defsfile | |
| 36 endc | |
| 37 | |
| 38 tylg set Drivr+Objct | |
| 39 atrv set ReEnt+rev | |
| 40 rev set $02 | |
| 41 edition set 5 | |
| 42 | |
| 43 mod eom,name,tylg,atrv,start,size | |
| 44 | |
| 45 * Device mem stuff - can make MMUTable bigger, but will take 2 pages of system | |
| 46 * RAM then for device memory | |
| 47 u0000 rmb DRVBEG+DRVMEM Reserve room for 1 entry drive table | |
| 48 MDFlag rmb 1 0=R0 descriptor, <>0=MD descriptor | |
| 49 numofBlk rmb 1 # of MMU blocks allocated for RAM drive | |
| 50 MMUTable rmb MAXBLOCK Table of MMU Block #'s being used. | |
| 51 size equ . | |
| 52 | |
| 53 fcb DIR.+SHARE.+PREAD.+PWRIT.+PEXEC.+READ.+WRITE.+EXEC. | |
| 54 | |
| 55 name fcs /Rammer/ | |
| 56 fcb edition | |
| 57 | |
| 58 * Terminate routine - deallocates RAM | |
| 59 L0024 lda <numofBlk,u Get # blocks we had allocated | |
| 60 beq L003D If none, exit | |
| 61 leay <MMUTable,u Point to MMU block table | |
| 62 IFNE H6309 | |
| 63 clre Hi byte of block # to allocate (always 0) | |
| 64 L002E ldf ,y Get block # | |
| 65 ELSE | |
| 66 L002E ldb ,y | |
| 67 ENDC | |
| 68 clr ,y+ Zero it out in table | |
| 69 IFNE H6309 | |
| 70 tfr w,x Block # to deallocate | |
| 71 ELSE | |
| 72 pshs a | |
| 73 clra | |
| 74 tfr d,x | |
| 75 puls a | |
| 76 ENDC | |
| 77 ldb #$01 1 block to deallocate | |
| 78 os9 F$DelRAM Deallocate the block | |
| 79 deca Dec # of blocks to clean out | |
| 80 bne L002E Do until entire RAM drive is deallocated | |
| 81 L003D clrb Exit w/o error | |
| 82 rts | |
| 83 | |
| 84 * Deallocate RAM allocated so far, exit with no RAM error | |
| 85 L003F bsr L0024 Deallocate all RAM Drive ram blocks | |
| 86 L0041 comb Exit no RAM left error | |
| 87 ldb #E$MemFul | |
| 88 rts | |
| 89 | |
| 90 * Init routine - only gets called once per driver inited. | |
| 91 * Called if you INIZ the device as well | |
| 92 * Entry: Y=Address of device descriptor | |
| 93 * U=Device mem area | |
| 94 * NOTE: All of device mem (Except V.PORT) is cleared to 0's | |
| 95 Init lda #1 | |
| 96 sta V.NDRV,u only can handle 1 drive descriptor | |
| 97 leax DRVBEG,u Point to start of drive table | |
| 98 sta DD.TOT+2,x Set DD.TOT to non 0 value | |
| 99 lda <M$Opt,y Get # of bytes in device descriptor table | |
| 100 deca | |
| 101 * Following is if 1st access to RAMMER is on /MD | |
| 102 beq GetStat 0 (/MD desciptor), then exit w/o error | |
| 103 ldb <IT.CYL+1,y Get LSB of # of cylinders | |
| 104 lda <IT.SID,y Get # of heads | |
| 105 mul Calculate # head/cyls total | |
| 106 lda <IT.SCT+1,y Get # of sectors/track | |
| 107 mul Calculate # of sectors for RAM drive | |
| 108 subd <IT.SCT,y Subtract 1 tracks worth | |
| 109 addd <IT.T0S,y Add in the special track 0's # sectors/track | |
| 110 std DD.TOT+1,x Save as # sectors on drive | |
| 111 addd #$001F Round up to nearest 8K block | |
| 112 IFNE H6309 | |
| 113 rold Shift # of 8K blocks needed into A | |
| 114 rold | |
| 115 rold | |
| 116 ELSE | |
| 117 rolb | |
| 118 rola | |
| 119 rolb | |
| 120 rola | |
| 121 rolb | |
| 122 rola | |
| 123 ENDC | |
| 124 cmpa #MAXBLOCK If higher than max, exit with mem full error | |
| 125 bhi L0041 | |
| 126 leax <MMUTable,u Point to RAM block table | |
| 127 IFNE H6309 | |
| 128 tfr a,e # blocks left to allocate | |
| 129 ENDC | |
| 130 L0078 ldb #$01 Try to allocate 1 8K RAM block | |
| 131 IFEQ H6309 | |
| 132 pshs a | |
| 133 ENDC | |
| 134 os9 F$AllRAM | |
| 135 IFEQ H6309 | |
| 136 puls a | |
| 137 ENDC | |
| 138 bcs L003F If error, deallocate RAM, and exit | |
| 139 inc <numofBlk,u Bump up # of blocks allocated | |
| 140 stb ,x+ Save MMU block # allocated in table | |
| 141 IFNE H6309 | |
| 142 dece Do until done all blocks requested | |
| 143 ELSE | |
| 144 deca | |
| 145 ENDC | |
| 146 bne L0078 | |
| 147 clrb No error & return | |
| 148 rts | |
| 149 | |
| 150 * Entry: B:X=LSN to read (only X will be used, even with 2 MB) | |
| 151 * Y=Path dsc. ptr | |
| 152 * U=Device mem ptr | |
| 153 Read pshs y,x Preserve path & device mem ptrs | |
| 154 bsr L00C8 Calculate MMU block & offset for sector | |
| 155 bcs L00A5 Error, exit with it | |
| 156 bsr L00AE Transfer sector from RAM drive to PD.BUF | |
| 157 puls y,x Restore ptrs | |
| 158 leax ,x Sector 0? | |
| 159 bne GetStat No, exit without error | |
| 160 ldx PD.BUF,y Get buffer ptr | |
| 161 leay DRVBEG,u Point to start of drive table | |
| 162 IFNE H6309 | |
| 163 ldw #DD.SIZ Copy the info we need into drive table | |
| 164 tfm x+,y+ | |
| 165 ELSE | |
| 166 ldb #DD.SIZ Copy the info we need into drive table | |
| 167 ReadLp lda ,x+ | |
| 168 sta ,y+ | |
| 169 decb | |
| 170 bne ReadLp | |
| 171 ENDC | |
| 172 * GetStat/SetStat - no calls, just exit w/o error | |
| 173 GetStat clrb | |
| 174 L00A7 rts | |
| 175 | |
| 176 L00A5 puls y,x,pc | |
| 177 | |
| 178 start bra Init | |
| 179 nop | |
| 180 bra Read | |
| 181 nop | |
| 182 bra Write | |
| 183 nop | |
| 184 bra GetStat | |
| 185 nop | |
| 186 bra GetStat Actually SetStat (no calls, so same routine) | |
| 187 nop | |
| 188 lbra L0024 Terminate (returns memory) | |
| 189 | |
| 190 * Entry: B:X = LSN to write | |
| 191 * Y=Path dsc. ptr | |
| 192 * U=Device mem ptr | |
| 193 Write bsr L00C8 Calculate MMU Block & offset for sector | |
| 194 bcs L00A7 Error,exit with it | |
| 195 exg x,y X=Sector buffer ptr, Y=Offset within MMU block | |
| 196 * Transfer between RBF sector buffer & RAM drive image sector buffer | |
| 197 * Called by both READ and WRITE (with X,Y swapping between the two) | |
| 198 L00AE orcc #IntMasks Shut IRQ's off | |
| 199 pshs x Preserve X | |
| 200 ldx <D.SysDAT Get ptr to system DAT image | |
| 201 ldb 1,x Get original System MMU block #0 | |
| 202 puls x Get X back | |
| 203 sta >$FFA0 Map in RAM drive block into block #0 | |
| 204 IFNE H6309 | |
| 205 ldw #$0100 256 byte transfer | |
| 206 tfm x+,y+ Copy between the two buffers | |
| 207 ELSE | |
| 208 clrb | |
| 209 WriteLp lda ,x+ | |
| 210 sta ,y+ | |
| 211 decb | |
| 212 bne WriteLp | |
| 213 ENDC | |
| 214 stb >$FFA0 Remap in system block 0 | |
| 215 andcc #^(IntMasks+Carry) Turn IRQ's back on & no error | |
| 216 rts | |
| 217 | |
| 218 * Subroutine to calculate MMU block # and offset based on sector # requested | |
| 219 * Entry: Y=path dsc. ptr | |
| 220 * U=device mem ptr | |
| 221 * B:X=LSN to calculate for | |
| 222 * Exit: A=MMU block # we need to map in | |
| 223 * X=offset within MMU block to get sector from (always <8K) | |
| 224 * Y=Sector buffer ptr for RBF | |
| 225 * MDFlag,u=0 if NOT MD, else MD | |
| 226 L00C8 clr MDFlag,u Flag that we are on "real" RAM Drive | |
| 227 IFNE H6309 | |
| 228 ldw PD.DEV,y Get our Device table entry ptr | |
| 229 ldw V$DESC,w Get device descriptor ptr | |
| 230 lda M$Opt,w Get size of options table | |
| 231 ELSE | |
| 232 pshs x | |
| 233 ldx PD.DEV,y Get our Device table entry ptr | |
| 234 ldx V$DESC,x Get device descriptor ptr | |
| 235 lda M$Opt,x Get size of options table | |
| 236 puls x | |
| 237 ENDC | |
| 238 deca | |
| 239 bne L00DB Not MD, skip ahead | |
| 240 inc MDFlag,u Flag we are on MD | |
| 241 sta <PD.SIZ,y | |
| 242 sta <PD.SIZ+3,y | |
| 243 sta <PD.SSZ,y | |
| 244 ldd <D.BlkMap+2 Get end of block memory ptr | |
| 245 subd <D.BlkMap Calc # of blocks of RAM | |
| 246 lda #32 * 32 for # of 'sectors' | |
| 247 mul | |
| 248 std <PD.SIZ+1,y Save as middle word of file size | |
| 249 std <PD.SSZ+1,y Save as segment size | |
| 250 bra L00DE Skip ahead (sector # will allow all 2 MB) | |
| 251 | |
| 252 L00DB tstb Test MSB of sector # | |
| 253 bne L010F <>0, exit with Sector error | |
| 254 L00DE pshs x Preserve LSW of sector # | |
| 255 ldd ,s Load it again into D | |
| 256 tst MDFlag,u We on MD? | |
| 257 bne L00EE Yes, skip ahead | |
| 258 leax DRVBEG,u Point to drive table | |
| 259 cmpd DD.TOT+1,x LSW of sector compared to table's # of sectors | |
| 260 bhs L010E Sector # too large, exit with error | |
| 261 L00EE equ * | |
| 262 IFNE H6309 | |
| 263 rold A=MMU block offset in RAM drive image | |
| 264 rold | |
| 265 rold | |
| 266 ELSE | |
| 267 rolb | |
| 268 rola | |
| 269 rolb | |
| 270 rola | |
| 271 rolb | |
| 272 rola | |
| 273 ENDC | |
| 274 tst MDFlag,u We on /MD? | |
| 275 bne L0100 Yup, skip calculating MMU stuff | |
| 276 leax <MMUTable,u Point to MMU table | |
| 277 lda a,x Get MMU block # we want | |
| 278 beq L010E If 0, exit with sector error | |
| 279 L0100 pshs a Save block # | |
| 280 clrb Calculate offset within 8k block we want | |
| 281 lda 2,s | |
| 282 anda #$1F Mask out all but within 8K address offset | |
| 283 std 1,s Save offset | |
| 284 ldy PD.BUF,y Get sector buffer address | |
| 285 puls x,a,pc Get offset, MMU block & return | |
| 286 | |
| 287 L010E leas 2,s Eat X on stack | |
| 288 L010F comb Exit with bad sector # | |
| 289 ldb #E$Sect | |
| 290 rts | |
| 291 | |
| 292 emod | |
| 293 eom equ * | |
| 294 end |