Assembly language (asm) programming questions. Also specify the processor or instruction set your question is related to as well as what assembler you are using. **NOTE**: For .NET assemblies, use the tag [.net-assembly] instead.
0
votes
0answers
5 views
Assembly call to ExitProcess returns error code
I'm calling exit process but it fails
eax set to 2 and error code ERROR_INVALID_ID_PARAMETER
is this related to stack alignment ? What's causing this error ?
push 0
call [ebp + 8]; exit process
...
4
votes
0answers
26 views
what is has_zero and find_zero in word_at_a_time.h used for
In linux kernel, inlucde/linux/word_at_a_time.h, there are two functions:
static inline long find_zero(unsigned long mask)
{
long byte = 0;
#ifdef CONFIG_64BIT
if (mask >> 32)
...
0
votes
1answer
20 views
Create an array in asm java compiler
Iam trying to create an array of integers using bytecode instructions
http://en.wikipedia.org/wiki/Java_bytecode_instruction_listings
Any ideas how to do it?
Thanks in advanced
0
votes
0answers
11 views
PIC 10F322 reading from db table
I built an assembly program using mpasm for the pic 10f322, and I want the program to read off all characters in my TABLE: by placing these values back into my WREG. When my code executes, it is ...
0
votes
1answer
38 views
Understanding Assembly Code
Could anyone provide some insight into the following assembly code:
oc_60: ; CODE XREF: seg000:0052j
mov cx, 3FFFh
mov si, 800h
xor di, di
loc_68: ; CODE XREF: seg000:0071j
lodsw
and si, 0FFBFh
xor ...
0
votes
0answers
19 views
fasm assembly 64 bit programming in winasm studio showing empty screen when trying to assemble a program
I have been programming in winasm studio using fasm for about 2 months. I am now using a 64 bit computer so I wanted to convert some of my programs to 64 bit. I started with a timer example here is ...
-4
votes
1answer
64 views
What would be your output for this assembly code [closed]
I am learning Assembly on x86 and trying to understand a programe which will add two number.
This code and done some modification on top of it to understand it better.
section .data
message1 db ...
1
vote
1answer
22 views
Reading a two digit number in assembly and storing it in a variable
I need to a program in assembly to read a two digit number from the user, store it in a variable and later print it.
I have tried a lot, but could not get through.
Here is my coding.
.model small
...
1
vote
0answers
37 views
Do the MMX registers always exist in modern processors?
When I look at diagrams and overviews of recent processors[1], I never see mention of the MMX registers MM0 - MM7. But from the specs, it seems like they still exist. Can one depend on them being ...
0
votes
2answers
66 views
add inline asm into C macro
I'm using mingw 4.7.2.
Could someone please tell me what's wrong in this MACRO
All I want to do is a simple asm macro which add two int and puts the result into result variable
#define ...
0
votes
1answer
33 views
Details of Syscall.RawSyscall() & Syscall.Syscall() in Go?
I'm reading source code in package syscall now, and met some problems:
Since I'm totally a noob of syscall and assembly, so don't hesitate to share anything you know about it :)
First about func ...
0
votes
0answers
14 views
exception after `call far TSS descriptor:offset`
I have a big problem that's got me stuck for a month!
I'm writing assembly code to do a task switch by call far [es:esi + TCB.addr_tss] in bochs, like picture 1.
Now I step into the new task, so I ...
0
votes
1answer
41 views
How to pass value from rax to xmm register
I want to pass value from %rax or memory to %xmm0 and this value shoud be of double, so i can later multiply %xmm0 by sth.
Currently im using this:
movq $1, -72(%rbp)
movq -72(%rbp), %rax
...
0
votes
0answers
35 views
How to identify a loop on the instruction level?
Can a direct branch instruction with a lower target address than the address of the branch instruction itself be considered as the beginning of a loop? Is this condition sufficient, or are there are ...
-1
votes
0answers
48 views
Anyone can explain the linux source code get_free_page()? [closed]
unsigned long get_free_page(void)
{
register unsigned long __res asm("ax");
__asm__("std ; repne ; scasb\n\t"
"jne 1f\n\t"
"movb $1,1(%%edi)\n\t"
"sall $12,%%ecx\n\t"
"addl ...
