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Comments:
<0> Hello. Is 'flat ***embler' a 'high level ***embler'?
<1> Alright, I am trying to figure something out. I was under the impression Windows blocked you from all interrupt calls and in/out hardware access. How come .com files make it possible?
<2> hi all
<2> I'm reading the info manual on GNU as(1). And it says this about local symbols: `C-B': This unusual character is included so you do not accidentally invent a symbol of the same name. The character has ASCII value of `\002' (control-B). I'm trying to get that to work, but no matter how hard I try I get an error.
<2> I have a local symbol "1:". I try to refer to it as "L1C-B1", "$L1C-B1", "L1", and "$L1"; but they all fail.
<2> keep I'm mind that I know C but I'm completely new to asm.
<3> yo , is there a sample code for typing hellow world
<2> Zap-W: write a hello.c file. Then do "gcc -S hello.c"
<2> Zap-W: that will tell gcc to create a file called hello.s, which is the code from hello.c translated into asm
<4> you might also find that your gcc supports -fverbose-asm, for adding some hints as to the context of the code.
<2> imaginator: awesome, ty for the tip :-)
<4> yw :)
<4> rutski: I'm tinkering with the C-B local symbol feature, to see if I can help. I wasn't aware of it before (never had a need for it before).
<2> imaginator: ah, neat; ty
<2> imaginator: it's in the info manual in section 5.3
<4> rutski: is there some reason that the sort of alias of 1b/$1b or 1f/$1f isn't good enough for what you're doing? why do you need the final symbol name?
<4> I read the description in the info pages as more about the final output of as, and the symbol generated for ld based on the patterns described.
<2> imaginator: I'm not "doing" anything really
<2> imaginator: I'm just reading the info manual to learn GAS and asm in general :-)
<2> imaginator: so I came across that local symbol referencing style and couldn't figure it out.
<4> ah, I see. I can show you an example of how I've used it in the past.
<2> imaginator: that would be perfect
<2> thanks :-)
<4> http://www.xmission.com/~georgeps/implementation/software/asm/sse2_memcpy-4.s
<2> imaginator: which line?
<4> look for local symbol names like 1: 2: 3: 4:
<4> basically those get internally translated by gas/GNU as to the type of symbol you were attempting to use.
<2> imaginator: well yea, but the part I'm interested is in how they're used; e.g. "L1C-B3".
<4> 1: .long 0 then you could refer to the address of that long allocated in whatever section as $1b ***uming it's backwards from the current location. When using it as a jump (which is mostly if not all of what the code does) you normally just refer to it like 1f, 3f and so on. That 1f gets translated to that type of L1C-B3 local symbol name.
<2> imaginator: I get the whole "N:" and "Nb" or "Nf" thing
<2> What I don't get is the L1C-B1 thing
<2> imaginator: ahh, so I'm not meant to use that L1C-B1 thing in the source; it's just an internal convention; gotcha
<4> yes
<4> you should be able to in fact verify this, by using objdump or nm I think
<2> imaginator: hmm, let me try (I thought that locals were just delete from the final object file)
<2> imaginator: nm and objdump -t didn't show them
<2> but then again I'm not very familiar with either nm or objdump
<2> zap0: is that you Zap-W?
<5> no i am zap0
<5> never used any other zap handle.
<5> but if it makes you feel better, sure.. i'll be Zap-W ;)
<2> ahh, ok; some guy named Zap-W was in here a while ago; that's why i ask
<2> heh
<5> was he as good looking as I ?
<6> Hi. I want to set delay value and repeat rate in 'setup.S'. I don't know ***embly but I am guessing I can just add BH 00h to set delay value for keyboard. but I REALLY have no idea. Can somebody guide me as to how to set a specific keboard rate rather than, as setup.S has it "Set the keyboard repeat rate to the max"?
<2> zap0: actually "Zap-W" does look a bit cooler than "zap0"
<2> ;)
<6> where can I paste some code?
<5> cool huh.. thats like butt ugly but wearing shades... i'd prefer to be good looking!
<5> otay, in a paste bin. Which platform are you talking about ?
<2> lol
<6> Linux. specifically setup.S the part that says: "# Set the keyboard repeat rate to the max"
<6> it looks like it would be easy thing to do if you knew..
<2> do any of you guys have any examples of the functionality described by the "Dollar Local Labels" section of the gas manual?
<6> I goodled Int 16/AH=03h. I see what I want there
<6> I want to set repeat rate to a specific value
<6> I'd like to set it to 10/sec
<6> problem is I have never done any ***embly. I dont' even have a license for it
<6> just by guessing, I think if I add a line: BL 0Ch may by what I want
<6> I have no idea
<6> am I even in the right channel?
<6> (wow, am I even online)
<5> find the value in the .s file to change, and change it..
<6> I dont see any of the values from "KEYBOARD - SET TYPEMATIC RATE AND DELAY" in setup.S
<6> there's only 3 lines there so I'm sure I'm not missing it
<6> (3 lines in the section I want to change)
<6> 1) movw $0x0305, %ax
<6> 2) xorw %bx, %bx
<6> 3) int $0x16
<6> that's it
<7> <7> saying that shellcode isn't similar to asm
<7> <Eulogy> it isn't!
<7> <Eulogy> it's machine code
<6> errr. I know somebody here can speak to my question.
<6> well, maybe I should read a book about it. Perhaps it's more appropriate question for a group
<5> otay, lookes a bit like ax=0x0305, bx=0 calls int 16;
<5> otay, so change the 0x0305 to what you need.
<6> Thank you so much.
<5> otay, so whats the problem ?
<6> wait
<6> will I be setting the delay value or the repeat rate if I do that?
<5> on which hardware ?
<6> i386
<5> what does the manual say?
<2> what is meant by the word "absolute" in the statement: "`as' has the following "prefix operators". They each take one argument, which must be absolute."
<5> it must be known at compile time
<2> ah, simple enough
<6> can you tell me if this page: http://lrs.uni-p***au.de/support/doc/interrupt-57/RB-1698.HTM gives the information I'm looking for? I don't know
<6> If I know that's right, at least I can ask a better question
<6> Paul Carter must be a genious
<5> otay, yes, that page seems to be good.
<6> I wouldn't mind learning the topic
<5> so you want something like ax=0x0305; bx=0x0100;
<5> otay, movw $0x0305, %ax movw $0x0100, %bx int $0x16
<6> I'm glad you clarified that
<6> what does that set the repeat rate to?
<5> 30/s
<5> 10/s would be movw $0x010C, %bx
<5> you can also query the current rate, by using 06 instead of 05 in ax.
<6> is the delay set too?
<5> delay is ~333ms
<6> can I set it to zero?
<5> no.
<5> you can lower it to 250ms
<6> how can I specify that?
<6> (Now I see 250ms is the low-end)
<5> you can figure it out from here... i gotta get back to wokr.
<6> common pleeese. just this one last question. I will be forever grateful
<6> I'm already grateful actually. I shouldn't bother you
<6> yah. Thanks for helping me.
<5> if you can't figure it out from what i have said, and that doc, then your problem is you, and some learning about ASM shall be required.
<6> I think the answer will be movw $0x00, %bx
<6> weather correct or not, that is my first line of asm. Brilliant!
<6> I think I'm ready to write an OS now
<5> yeah, call it Otanix.
<2> Hi all
<2> I'm confused about what .comm does
<2> I have f1.c and f2.c
<2> both files declare and define "static int blarg = 125" at the top
<2> well.. one does = 125, the other does = 562
<2> but anyway
<2> I do gcc -S f1.c f2.c
<8> then .comm isn't used. it'll be local symbol, defined in .data normally.
<2> and both f1.c and f2.c define blarg and set it to the appropriate value
<2> mwk: but .comm is used
<2> mwk: I mean... it's there in both .s files
<8> how?
<2> .comm blarg,4,4
<2> in both files
<9> rutski: which version of gcc?
<2> lindi-: 4.1.1
<2> Here's both f1.s and f2.s concatenated into the same file: http://www.rutski89.com:31597/upload/both-files.s
<2> oh
<2> shoot
<8> umm...
<2> .comm isn't there anymore
<8> where's .comm?
<2> hmm, well that was a test case I just wrote up
<9> ;)
<2> so I must have done something differently originally
<2> I wonder what it was
<2> oh
<2> my bad
<2> I forgot to do revert-buffer in emacs after recompiling the C source into ASM
<2> so I was looking at an older version of the .s
<2> so in that case
<2> each file's .data section is local to that file?
<8> no.
<8> .data sections are global
<8> it's just symbol names that can be local
<2> but unless you declare them .globl, they symbols aren't, are they?
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