Hello. Help me please, i don't understand this code:
...
BUFFER = 0x0600
...
rep movs jmpf BUFFER+migrate, 0 ;???
migrate:
findactive:
testb dl,dl ; ???
jns nextdisk
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177answers:
1
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A:
I'm an old x86 coder. I have to admit I don't understand your code either. The "movs" instruction line looks illegal. Are you sure you've transcribed the code correctly?
Ira Baxter
2010-05-30 18:15:15
this code may be AVC(or AVK) - assembler for minix os.translate testb to test, jmpf to jmp, and movs to mov.And help me understend this code plz.
GLeBaTi
2010-05-30 18:20:41
movs ins't the same as mov, if they are using the intel mnemonics. If his isn't microsoft syntax, then my best guess is: [rep movs] means "repeat movs for ECX count" (see Intel instrution set manual). [jmpf BUFFER+migrate] means go to the label migrate + 0x600; that location isn't listed in your code and this is a pretty strange thing to say. [migrate:] and [findactive:] are code labels on the testb instruction. [testb dl,dl] means check to see if the [dl] register is signed/zero, and [jns nextdisk] branches if the [dl] register top bit was set.
Ira Baxter
2010-05-31 00:19:26
.... somehow I doubt this analysis will help you. I think you've left a lot of critical code out of this example. And what do you mean *may* be AVC/AVK? Either you know what it is, or you don't. If you don't know which assembler it is, you'll never quite be sure you've understood what it says.
Ira Baxter
2010-05-31 00:21:06
thanks for the help.I forgot the name: ACK(http://en.wikipedia.org/wiki/Amsterdam_Compiler_Kit)
GLeBaTi
2010-05-31 06:01:34