Difference between revisions of "Load file into RAM"
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(Created page with "Actually BIOS 2 CD_GetSector? doesn't load file according to documentation - transfers file from "buffer" to main ram in the background. I have been wrong before 00020650: 3c...") |
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Actually BIOS 2 CD_GetSector? doesn't load file according to documentation - transfers file from "buffer" to main ram in the background. I have been wrong before | Actually BIOS 2 CD_GetSector? doesn't load file according to documentation - transfers file from "buffer" to main ram in the background. I have been wrong before | ||
00020650: 3c028003 lui r2,0x8003 | 00020650: 3c028003 lui r2,0x8003 | ||
| − | 00020654: 8c421b40 lw r2,0x1b40(r2) | + | 00020654: 8c421b40 lw r2,0x1b40(r2) # CDREG0 |
00020658: 3c060002 lui r6,0x0002 | 00020658: 3c060002 lui r6,0x0002 | ||
| − | 0002065c: a0400000 sb r0,0x0000(r2) | + | 0002065c: a0400000 sb r0,0x0000(r2) # store 0 at CDREG0 |
00020660: 3c038003 lui r3,0x8003 | 00020660: 3c038003 lui r3,0x8003 | ||
| − | 00020664: 8c631b4c lw r3,0x1b4c(r3) | + | 00020664: 8c631b4c lw r3,0x1b4c(r3) # CDREG3 |
| − | 00020668: 34020080 ori r2,r0,0x0080 | + | 00020668: 34020080 ori r2,r0,0x0080 # CDREG0 && 0x80 |
| − | 0002066c: a0620000 sb r2,0x0000(r3) | + | 0002066c: a0620000 sb r2,0x0000(r3) # store unknown? in CDREG3 |
00020670: 3c028003 lui r2,0x8003 | 00020670: 3c028003 lui r2,0x8003 | ||
| − | 00020674: 8c421b74 lw r2,0x1b74(r2) | + | 00020674: 8c421b74 lw r2,0x1b74(r2) # hardware register address |
| − | 00020678: 34c60943 ori r6,r6,0x0943 | + | 00020678: 34c60943 ori r6,r6,0x0943 # r6 = 0x00020943 |
| − | 0002067c: ac460000 sw r6,0x0000(r2) | + | 0002067c: ac460000 sw r6,0x0000(r2) # ? |
00020680: 3c038003 lui r3,0x8003 | 00020680: 3c038003 lui r3,0x8003 | ||
00020684: 8c631b50 lw r3,0x1b50(r3) | 00020684: 8c631b50 lw r3,0x1b50(r3) | ||
00020688: 34021323 ori r2,r0,0x1323 | 00020688: 34021323 ori r2,r0,0x1323 | ||
| − | 0002068c: ac620000 sw r2,0x0000(r3) | + | 0002068c: ac620000 sw r2,0x0000(r3) # 1323 into hardware address |
00020690: 3c038003 lui r3,0x8003 | 00020690: 3c038003 lui r3,0x8003 | ||
00020694: 8c631b78 lw r3,0x1b78(r3) | 00020694: 8c631b78 lw r3,0x1b78(r3) | ||
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000206a0: 00000000 nop | 000206a0: 00000000 nop | ||
000206a4: 34428000 ori r2,r2,0x8000 | 000206a4: 34428000 ori r2,r2,0x8000 | ||
| − | 000206a8: ac620000 sw r2,0x0000(r3) | + | 000206a8: ac620000 sw r2,0x0000(r3) # |
000206ac: 3c028003 lui r2,0x8003 | 000206ac: 3c028003 lui r2,0x8003 | ||
| − | 000206b0: 8c421b7c lw r2,0x1b7c(r2) | + | 000206b0: 8c421b7c lw r2,0x1b7c(r2) # load hardware pointer for file -> ram address |
000206b4: 00000000 nop | 000206b4: 00000000 nop | ||
000206b8: ac440000 sw r4,0x0000(r2) # store input 1 (memory address to store file into ram?) | 000206b8: ac440000 sw r4,0x0000(r2) # store input 1 (memory address to store file into ram?) | ||
000206bc: 3c020001 lui r2,0x0001 | 000206bc: 3c020001 lui r2,0x0001 | ||
000206c0: 3c038003 lui r3,0x8003 | 000206c0: 3c038003 lui r3,0x8003 | ||
| − | 000206c4: 8c631b80 lw r3,0x1b80(r3) | + | 000206c4: 8c631b80 lw r3,0x1b80(r3) # no ref |
| − | 000206c8: 00a22825 or r5,r5,r2 #file size (?) OR 0x00010000 (not sure what this accomplishes. stores it to what I assume communicates with the CD-ROM reader) | + | 000206c8: 00a22825 or r5,r5,r2 # file size (?) OR 0x00010000 (not sure what this accomplishes. stores it to what I assume communicates with the CD-ROM reader) |
000206cc: ac650000 sw r5,0x0000(r3) | 000206cc: ac650000 sw r5,0x0000(r3) | ||
000206d0: 3c038003 lui r3,0x8003 | 000206d0: 3c038003 lui r3,0x8003 | ||
| − | 000206d4: 8c631b40 lw r3,0x1b40(r3) | + | 000206d4: 8c631b40 lw r3,0x1b40(r3) # CDREG0 |
000206d8: 00000000 nop | 000206d8: 00000000 nop | ||
| − | 000206dc: 90620000 lbu r2,0x0000(r3) | + | 000206dc: 90620000 lbu r2,0x0000(r3) # |
000206e0: 00000000 nop | 000206e0: 00000000 nop | ||
000206e4: 30420040 andi r2,r2,0x0040 | 000206e4: 30420040 andi r2,r2,0x0040 | ||
| − | 000206e8: 1040fffb beq r2,r0,0x000206d8 | + | 000206e8: 1040fffb beq r2,r0,0x000206d8 # check if command is still being processed (loop here until finished) |
000206ec: 3c021100 lui r2,0x1100 | 000206ec: 3c021100 lui r2,0x1100 | ||
000206f0: 3c038003 lui r3,0x8003 | 000206f0: 3c038003 lui r3,0x8003 | ||
| − | 000206f4: 8c631b84 lw r3,0x1b84(r3) | + | 000206f4: 8c631b84 lw r3,0x1b84(r3) # no ref |
000206f8: 00000000 nop | 000206f8: 00000000 nop | ||
000206fc: ac620000 sw r2,0x0000(r3) | 000206fc: ac620000 sw r2,0x0000(r3) | ||
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00020710: 3c030100 lui r3,0x0100 | 00020710: 3c030100 lui r3,0x0100 | ||
00020714: 00431024 and r2,r2,r3 | 00020714: 00431024 and r2,r2,r3 | ||
| − | 00020718: 10400007 beq r2,r0,0x00020738 | + | 00020718: 10400007 beq r2,r0,0x00020738 # |
0002071c: 00801821 addu r3,r4,r0 | 0002071c: 00801821 addu r3,r4,r0 | ||
00020720: 3c040100 lui r4,0x0100 | 00020720: 3c040100 lui r4,0x0100 | ||
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0002073c: 8c631b50 lw r3,0x1b50(r3) | 0002073c: 8c631b50 lw r3,0x1b50(r3) | ||
00020740: 34021325 ori r2,r0,0x1325 | 00020740: 34021325 ori r2,r0,0x1325 | ||
| − | 00020744: ac620000 sw r2,0x0000(r3) | + | 00020744: ac620000 sw r2,0x0000(r3) #store 1b501325 as hardware register address |
00020748: 03e00008 jr r31 | 00020748: 03e00008 jr r31 | ||
| − | 0002074c: 00001021 addu r2,r0,r0 | + | 0002074c: 00001021 addu r2,r0,r0 # always return 0 (maybe it's not CDGetsector? but it could be an older version...) |
Revision as of 10:33, 8 July 2023
Actually BIOS 2 CD_GetSector? doesn't load file according to documentation - transfers file from "buffer" to main ram in the background. I have been wrong before
00020650: 3c028003 lui r2,0x8003 00020654: 8c421b40 lw r2,0x1b40(r2) # CDREG0 00020658: 3c060002 lui r6,0x0002 0002065c: a0400000 sb r0,0x0000(r2) # store 0 at CDREG0 00020660: 3c038003 lui r3,0x8003 00020664: 8c631b4c lw r3,0x1b4c(r3) # CDREG3 00020668: 34020080 ori r2,r0,0x0080 # CDREG0 && 0x80 0002066c: a0620000 sb r2,0x0000(r3) # store unknown? in CDREG3 00020670: 3c028003 lui r2,0x8003 00020674: 8c421b74 lw r2,0x1b74(r2) # hardware register address 00020678: 34c60943 ori r6,r6,0x0943 # r6 = 0x00020943 0002067c: ac460000 sw r6,0x0000(r2) # ? 00020680: 3c038003 lui r3,0x8003 00020684: 8c631b50 lw r3,0x1b50(r3) 00020688: 34021323 ori r2,r0,0x1323 0002068c: ac620000 sw r2,0x0000(r3) # 1323 into hardware address 00020690: 3c038003 lui r3,0x8003 00020694: 8c631b78 lw r3,0x1b78(r3) 00020698: 00000000 nop 0002069c: 8c620000 lw r2,0x0000(r3) 000206a0: 00000000 nop 000206a4: 34428000 ori r2,r2,0x8000 000206a8: ac620000 sw r2,0x0000(r3) # 000206ac: 3c028003 lui r2,0x8003 000206b0: 8c421b7c lw r2,0x1b7c(r2) # load hardware pointer for file -> ram address 000206b4: 00000000 nop 000206b8: ac440000 sw r4,0x0000(r2) # store input 1 (memory address to store file into ram?) 000206bc: 3c020001 lui r2,0x0001 000206c0: 3c038003 lui r3,0x8003 000206c4: 8c631b80 lw r3,0x1b80(r3) # no ref 000206c8: 00a22825 or r5,r5,r2 # file size (?) OR 0x00010000 (not sure what this accomplishes. stores it to what I assume communicates with the CD-ROM reader) 000206cc: ac650000 sw r5,0x0000(r3) 000206d0: 3c038003 lui r3,0x8003 000206d4: 8c631b40 lw r3,0x1b40(r3) # CDREG0 000206d8: 00000000 nop 000206dc: 90620000 lbu r2,0x0000(r3) # 000206e0: 00000000 nop 000206e4: 30420040 andi r2,r2,0x0040 000206e8: 1040fffb beq r2,r0,0x000206d8 # check if command is still being processed (loop here until finished) 000206ec: 3c021100 lui r2,0x1100 000206f0: 3c038003 lui r3,0x8003 000206f4: 8c631b84 lw r3,0x1b84(r3) # no ref 000206f8: 00000000 nop 000206fc: ac620000 sw r2,0x0000(r3) 00020700: 3c048003 lui r4,0x8003 00020704: 8c841b84 lw r4,0x1b84(r4) 00020708: 00000000 nop 0002070c: 8c820000 lw r2,0x0000(r4) 00020710: 3c030100 lui r3,0x0100 00020714: 00431024 and r2,r2,r3 00020718: 10400007 beq r2,r0,0x00020738 # 0002071c: 00801821 addu r3,r4,r0 00020720: 3c040100 lui r4,0x0100 00020724: 8c620000 lw r2,0x0000(r3) 00020728: 00000000 nop 0002072c: 00441024 and r2,r2,r4 00020730: 1440fffc bne r2,r0,0x00020724 00020734: 00000000 nop 00020738: 3c038003 lui r3,0x8003 0002073c: 8c631b50 lw r3,0x1b50(r3) 00020740: 34021325 ori r2,r0,0x1325 00020744: ac620000 sw r2,0x0000(r3) #store 1b501325 as hardware register address 00020748: 03e00008 jr r31 0002074c: 00001021 addu r2,r0,r0 # always return 0 (maybe it's not CDGetsector? but it could be an older version...)
