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中国DOS联盟论坛 » DOS启动盘 & LOGO技术 (启动盘室) » Assembly Question View 526 Replies 0
Original Poster Posted 2003-09-27 00:00 ·  中国 北京 联通
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pnpAllocatePmmBlock PROC NEAR PUBLIC
push ax
invoke pmmServicesDispatcher, PMM_ALLOCATE_FUNCTION, eax, edx, cx What does this line mean?

shl edx, 16 ; Convert 32 bit DX:AX into 32 bit EDX
mov dx, ax ; Put AX to lower EDX

cmp edx, 0 ; Was the allocation successful?
jne allocGood ; DX:AX = 00000000 if failed

mov ax, TP_PMM_INIT ; Put PMM test point in AX
jmp postTerminalError ; Call terminal error handler

allocGood:
pop ax
ret
pnpAllocatePmmBlock ENDP
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