Low-level programming language used to send instructions (machine code) directly to a microprocessor. For assembling hardware, use [computer-building] instead.
Questions tagged [assembly]
69 questions
29
votes
5 answers
How to check if a binary requires SSE4 or AVX on Linux
On Linux,/proc/cpuinfoallows one to check all the CPU flags the machine has in a simple way.
Usually, if a program requires a superset of a machine's instruction set, the easiest way to determine this is to run it and see whether it raises…
user2284570
- 2,020
21
votes
3 answers
Latency of CPU instructions on x86 and x64 processors
I'm looking for some table or something similar that could help me to calculate efficiency of assembly code.
As I know bit shifting takes 1 CPU clock, but I really looking how much takes addition (subtraction should take the same), multiplication…
ST3
- 785
19
votes
1 answer
What actually happens when I run "cli; hlt" on my Linux system?
So I recently figured out that there's a HLT opcode for halting the CPU. Cool, let's see what happens!
user@box:~$ cat > test.c
int main(void)
{
__asm__("HLT");
return 0;
}
user@box:~$ gcc -o test test.c
user@box:~$ ./test
Segmentation fault…
secretpow
- 301
11
votes
3 answers
Why can't we understand the content of a binary file after compiled?
As far I know, every program consists of a pack of processor instructions with some specific data variables(float, int, char...) to work on the processor registers.
So, the first thing that I thought about it(a long time ago) is that if you know…
Diogo
- 30,792
11
votes
3 answers
How prevalent are old x64 processors lacking the cmpxchg16b instruction?
The cmpxchg16b instruction for doing atomic 128 bit memory exchanges is not supported on old versions of the x64 processor but it seems like this has been supported by newer versions of the processor for several years now. How likely am I to…
Christopher Barber
- 211
- 1
- 2
- 7
7
votes
2 answers
How to see all the bits of a file?
I'm looking for a way to see all the bits of a file. I want to see all the 01's in my file, because I want to know what changes exactly happen when I edit a file using a closed-source application.
Mostafa Farzan
- 143
- 1
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- 5
5
votes
4 answers
Vim assembly formatting
Vim is not properly indenting assembly code, regardless of if I want it to do it automatically or if I try gg=G it'll just says ## lines indented even though it didn't change anything and all my text is still left-aligned.
user339365
- 195
5
votes
5 answers
Old Technologies About Floppy
I have a floppy disk with an unknown FS-(FileSystem). I want to make a copy from it but I can't because both Windows and Linux seem to be unable to read from it.
I tried many of the most popular apps to make image files (for example isomeric,…
repozitor
- 61
5
votes
1 answer
Windows --> Assembly folder typical size: aka GAC
I am a .net developer on a Win 7 RC1 (x64) machine and I happened to notice that my GAC(Global Assembly Cache) folder is 1.2 GBs in size(1700 files).
This got me wondering what the "normal" size is and what implications having one this large may…
4
votes
1 answer
IDE for assembly on pendrive
I need a portable IDE for assembly.
What can you recommend me ?
oneat
- 3,401
3
votes
2 answers
Intel assembler/architecture documentation?
Would anyone know where the best "official" Intel documentation regarding the low level architecture/assembler internals would be? How the ESP works, the various registers- fetching values from RAM etc?
The Intel website is massive and I could find…
Ian
- 31
3
votes
2 answers
Is there any way to see what my CPU is doing at the "assembly level"?
I was looking at how Assembly Language works, because I want to learn how the complex and fancy things my computer does actually happen at the CPU register/hardware levels. Is there any way to see what's going on during normal computer use?
I want…
MetaGuru
- 3,799
3
votes
1 answer
Understanding the nop byte(s)
Ok, so I was reading through the AMD64 manuels and knowing that nop is really an xchg eax, eax, I looked at the xchg and found something interesting, that it seems a byte can be encoded into the instruction for specifying the registers (apologies…
Cole Tobin
- 626
2
votes
4 answers
What is the maximum addressable memory?
I just started learning assembly.
My laptop specification says:
Microprocessor: Intel Core Duo processor T2300
Microprocessor Cache: 2MB L2 Cache
Memory Max: 2048MB
Memory: 1024MB 667MHz DDR2 System Memory (2 Dimm)
"Intel Core Duo processor…
mlguy
2
votes
1 answer
Would x86 assembly work on x64 processors?
Would x86 assembly compile on an x64 machine and still work properly? If not, what is the difference between x86 assembly and x64 assembly?
verymessi
- 85