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view level2/modules/kernel/fallram.asm @ 2758:e4a0f58a5f9b

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Found that people who do not have the envirornment variable NITROS9DIR set before building the project get a error missing file "/rules.mak". Found this is caused do to the fact that the code to set this envirornment variable is in the rules.mak which can't get loaded. To fix this the code needed to set the envirornment variable that is in the rules.mak is now in the makefile(s) right before the include for the rules.mak file. This should fix the problem for those who do not have the NITROS9DIR envirornment variable preset.
author drencor-xeen
date Mon, 14 Jan 2013 14:37:46 -0600
parents 5ecf6e023a64
children 039ddb7c8ad7
line wrap: on
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**************************************************
* System Call: F$AllRAM
*
* Function: Allocate RAM blocks
*
* Input:  B = Desired block count
*
* Output: D = Beginning RAM block number
*
* Error:  CC = C bit set; B = error code
*
FAllRAM  ldb   R$B,u        Get # blocks requested
         pshs  b,x,y        Save regs
         ldx   <D.BlkMap    Get ptr to start of block map
L0974    leay  ,x           Point Y to current block
         ldb   ,s           Get # blocks requested
srchblk  cmpx  <D.BlkMap+2  Hit end of map yet?
         bhs   L0995        Yes, exit with No RAM error
         lda   ,x+          Get block marker
         bne   L0974        Already used, start over with next block up
         decb               Dec # blocks still needed
         bne   srchblk      Still more, keep checking
* Entry: Y=ptr to start of memory found
* Note: Due to fact that block map always starts @ $200 (up to $2FF), we
*       don't need to calc A
L0983    tfr   y,d          Copy start of requested block mem ptr to D (B)
         lda   ,s           Get # blocks requested
         stb   ,s           Save start block # 
L098D    inc   ,y+          Flag blocks as used
         deca                (for all blocks allocated)
         bne   L098D        Do until done
         puls  b            Get start block #
         clra               (allow for D as per original calls)
         std   R$D,u        Save for caller
         puls  x,y,pc       Restore regs & return

L0995    comb               Exit with No RAM error
         ldb   #E$NoRAM
         stb   ,s
         puls  b,x,y,pc


**************************************************
* System Call: F$AlHRAM
*
* Function: Allocate RAM blocks from top of RAM
*
* Input:  B = Desired block count
*
* Output: D = Beginning RAM block number
*
* Error:  CC = C bit set; B = error code
*
FAlHRAM  ldb   R$B,u        Get # blocks to allocate
         pshs  b,x,y        Preserve regs
         ldx   <D.BlkMap+2  Get ptr to end of block map
L09A9    ldb   ,s           Get # blocks requested
L09AB    cmpx  <D.BlkMap    Are we at beginning of RAM yet?
         bls   L0995        Yes, exit with No RAM error
         lda   ,-x          Get RAM block marker
         bne   L09A9        If not free, start checking next one down
         decb               Free block, dec # blocks left to find count
         bne   L09AB        Still more needed, keep checking
         tfr   x,y          Found enough contigous blocks, move ptr to Y
         bra   L0983        Go mark blocks as used, & return info to caller