Questions tagged [intel]

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1answer
177 views

Understand the CPU cycles of x86 instruction bsr/bsf

I am on the hook to analysis some "timing channels" of some x86 binary code. I am posting one question to comprehend bsf/bsr opcode. So high-levelly, these two opcodes can be modeled as a "loop", ...
2
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1answer
196 views

How do the PSHUFLW and PSHUFD instructions work?

I have been trying to figure out exactly what is happening with these instructions and can't make sense of them. I can see that the PSHUFLW instruction acts upon the first 16 bytes of the XMM register ...
3
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1answer
115 views

Undocumented MSR Machine Specific register

I'm reversing the BIOS of my laptop, for fun and for learning something new. Inside it, I just stepped into this piece of code: mov ecx, 13Ah rdmsr and eax, 1 jnz SkipCacheAsRAM Looking ...
3
votes
1answer
123 views

Basic hello world stack manipulation troubles

I'm a beginner in reverse engineering, and as a beginner I started to read "Reverse Engineering for beginers". Here is the hello world program from the book (taken from chapter 3, page 12) : Now ...
1
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1answer
536 views

NASM, MASM, Intel, AT&T' syntax?

I see word NASM, MASM, Intel, AT&T. I am confused between them. Is it different types of assembly?
0
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1answer
248 views

IDA Pro Address doesn't correlate to Immunity Debugger address

I'm trying to use immunity debugger to step through a confusing binary. When I open it in IDA Pro, I see certain addresses next to the instructions: .text:01001392 inc eax When I ...
3
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2answers
1k views

What does XREF mean?

I have been learning about the x86 assembly language by analyzing a binary using radare2 that is stored on a Intel 80386 machine. When I have been analyzing functions on the binary, I noticed that "...
1
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2answers
192 views

Intel PIN (TracerPIN): adding modification of registers

Basically I just would like to modify the following code: https://github.com/SideChannelMarvels/Tracer/tree/master/TracerPIN (based on Intel PIN) in order to be able to modify the content of some ...
1
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0answers
545 views

Reverse Intel hex to programming code

I have a file in the Intel hex format, which was taken of from a pic16F1705 chip. I need to find a way to disassemble it into some form of human friendly programming language in order to make some ...
0
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1answer
308 views

How to debug Portable executable for AMD64 in IDA PRO?

How can I debug Portable executable for AMD64 in IDA PRO if I have Intel processor?
1
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1answer
449 views

Optimized vs Unoptimized code comparison

After reading a number of blog posts, forums, and watching tutorials I figured I would start learning to reverse software the old fashion way. Creating simple C files and looking at their disassembly....
1
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1answer
355 views

Basic assembly query [closed]

I wrote a program which will add two numbers in assembly. When I do a system call for scanf(), the instruction looks like this: mov rcx, num1 Note: I have defined num1 in the bss section as: num1 ...
0
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1answer
129 views

Detecting user<->kernel transitions with hypervisor

Is it possible to use a hypervisor to trap all ring0<->ring3 transitions (both 0->3 and 3->0)?
2
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1answer
300 views

igdlh64.inf modify custom resolution

I have some dead pixels in top couple of rows of my cheap Win 10 tablet. To alleviate that, I wanted to use the custom resolution option in Intel graphics management panel, however, I cannot choose ...
0
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1answer
98 views

Intel PIN and nm unable to capture binary symbols

I'm trying to generate a log of all identified symbols in a binary file. The application i'm trying to inspect is busybox. I've created a Pin Tool that successfully captures symbols (no demangling) ...
0
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2answers
1k views

Intel syntax - Meaning of jmp/call instruction with $+5 operand

I'm currently parsing a lot of assembly files and don't understand a specific jmp or call with $+5 as operand: call $+5 jmp $+5 To provide more context I grepped some of the occurrences: mov esp, [...