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comparison level2/modules/kernel/ffreehb.asm @ 1345:1da8ab9ba433

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Added consistent comments to each system call
author boisy
date Wed, 17 Sep 2003 17:26:37 +0000
parents 436443bd9b8e
children 1451bc7ef0b9
comparison
equal deleted inserted replaced
1344:dfd2e7080b4d 1345:1da8ab9ba433
1 * F$FreeHB entry point (Called from F$MapBlk - called from SS.MpGPB) 1 **************************************************
2 * System Call: F$FreeHB
3 *
4 * Function: Get free high block
5 *
6 * Called from F$MapBlk and from SS.MpGPB)
7 *
8 * Input: B = Block count
9 * Y = DAT image pointer
10 *
11 * Output: A = High block number
12 *
13 * Error: CC = C bit set; B = error code
14 *
2 FFreeHB ldb R$B,u Get # blocks requested 15 FFreeHB ldb R$B,u Get # blocks requested
3 ldy R$Y,u Get DAT Img ptr 16 ldy R$Y,u Get DAT Img ptr
4 bsr L0A31 Go find free blocks in high part of DAT 17 bsr L0A31 Go find free blocks in high part of DAT
5 L0A2C bcs L0A30 Couldn't find any, exit with error 18 L0A2C bcs L0A30 Couldn't find any, exit with error
6 sta R$A,u Save starting block # 19 sta R$A,u Save starting block #
39 cmpa 3,s Have we got enough? 52 cmpa 3,s Have we got enough?
40 bne L0A71 No, keep looking 53 bne L0A71 No, keep looking
41 L0A82 leas 2,s Eat temporary stack 54 L0A82 leas 2,s Eat temporary stack
42 puls d,x,pc Restore reg, error code & return 55 puls d,x,pc Restore reg, error code & return
43 56
44 * F$FreeLB entry point (WHERE DOES THIS EVER GET CALLED FROM???) 57
45 * Rodney says: "it's called via os9p1 syscall vector in line 393" 58 * WHERE DOES THIS EVER GET CALLED FROM???
59 * Rodney says: "It's called via os9p1 syscall vector in line 393"
46 FSFreeLB ldb R$B,u Get block count 60 FSFreeLB ldb R$B,u Get block count
47 ldy R$Y,u Get ptr to DAT Image 61 ldy R$Y,u Get ptr to DAT Image
48 bsr L0A4B Go find block #'s 62 bsr L0A4B Go find block #'s
49 bra L0A2C Do error checking & exit (since never called, 63 bra L0A2C Do error checking & exit (since never called,
50 * not worried about speed) 64 * not worried about speed)
55 nega -(-1)=+1 69 nega -(-1)=+1
56 subb #9 Drop block count to -8 to -1 (invert within 8) 70 subb #9 Drop block count to -8 to -1 (invert within 8)
57 negb Negate so it is a positive # again 71 negb Negate so it is a positive # again
58 bra L0A56 Go into main find loop 72 bra L0A56 Go into main find loop
59 73
60 * F$FreeLB entry point 74
75 **************************************************
76 * System Call: F$FreeLB
77 *
78 * Function: Get free low block
79 *
80 * Input: B = Block count
81 * Y = DAT image pointer
82 *
83 * Output: A = Low block number
84 *
85 * Error: CC = C bit set; B = error code
86 *
61 FFreeLB ldd R$D,u 87 FFreeLB ldd R$D,u
62 ldx R$X,u 88 ldx R$X,u
63 ldu R$U,u 89 ldu R$U,u
64 L0A8C pshs d,x,y,u 90 L0A8C pshs d,x,y,u
65 leay <P$DATImg,x 91 leay <P$DATImg,x