Mercurial > hg > Members > kono > nitros9-code
view level2/modules/kernel/fmapblk.asm @ 3295:6b7a7b233925 default tip
makefile: Allow PORTS with level1/2 mix
https://sourceforge.net/p/nitros9/feature-requests/10/
| author | Tormod Volden <debian.tormod@gmail.com> |
|---|---|
| date | Tue, 19 Apr 2022 18:12:17 +0200 |
| parents | 039ddb7c8ad7 |
| children |
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************************************************** * System Call: F$MapBlk * * Function: Map specific block * * Input: B = Number of blocks * X = Beginning block number * * Output: U = Address of first block * * Error: CC = C bit set; B = error code * FMapBlk lda R$B,u get # blocks beq L0BAA can't map 0 blocks, return error cmpa #DAT.BlCt within range of DAT image? bhi L0BAA no, return error leas -$10,s make a buffer to hold DAT image ldx R$X,u get start block # ldb #1 block increment value IFNE H6309 * Change to W 05/19/93 - used W since one cycle faster per block tfr s,w point to buffer FMapBlk2 stx ,w++ save block # to buffer ELSE tfr s,y point to buffer FMapBlk2 stx ,y++ save block # to buffer ENDC abx Next block deca done? bne FMapBlk2 no, keep going ldb R$B,u get block count again ldx <D.Proc get process pointer leay <P$DATImg,x point to DAT image os9 F$FreeHB find the highest free block offset bcs L0BA6 no room, return error IFNE H6309 tfr d,w Preserve start block # & # of blocks ELSE pshs d ENDC lsla Multiply start block # by 32 lsla lsla lsla lsla clrb std R$U,u save address of first block IFNE H6309 tfr w,d Restore offset ELSE puls d ENDC leau ,s move DAT image into process descriptor os9 F$SetImg Change process dsc to reflect new blocks L0BA6 leas <$10,s Eat DAT image copy & return rts L0BAA comb Illegal Block address error ldb #E$IBA rts