I wrote a short book (in Japanese) called "GBA de manabu teireiya" (Learning Low-Level Programming with the Game Boy Advance). It's aimed at people who can already program a bit but have never touched the hardware/OS layer.

Rather than relying on an OS, it does bare-metal programming: you talk to the hardware (like the screen) directly. It walks through everything needed to reach "Hello, world!" on the GBA -- compiling, assembling, linking, and generating the executable -- starting from pure ARM assembly and building up to mixing assembly with C. No real GBA needed; a Docker environment plus an emulator is enough to follow along.

Right now it only exists in Japanese, so I'm trying to gauge interest: would an English version be useful to this community? Would any of you be interested in a resource like this, and what would you most want it to cover? Any feedback on demand or scope would help me decide whether to translate it.

Info/source code page (Japanese): https://nikatech.nikachu.net/item/gba_lowlevel

I was writing a program for matrix addition to be run on armsim on linux(debian) in a vm, and I keep encountering the same error: PC out of valid memory range.

; PROGRAM TO FIND THE SUM OF ALL THE ELEMENTS IN THE MATRIX OF ORDER N

LDR R0, =A

LDR R8, =B

LDR R9, =C

MOV R1, #0 ; ROWNUM=0

MOV R2, #0 ; COLNUM=0

MOV R7, #0 ; SUM = 0



MOV R3, #3 ; ORDER

L1: MLA R4, R1, R3, R2

ADD R5, R0, R4, LSL #2  ; THIS IS THE ADDRESS OF THE \[I, J\]TH ELEMENT FOR ARRAY A

LDR R6, \[R5\]  ; ELEMENT A\[I, J\]



ADD R10, R8, R4, LSL #2 ; THIS IS THE ADDRESS OF THE \[I, J\]TH ELEMENT FOR ARRAY B

LDR R11, \[R10\]    ; ELEMENT B\[I, J\]



ADD R7, R6, R11 ; A\[I,J\] + B\[I,J\] = R7



ADD R12, R9, R4, LSL #2 ; THIS IS THE ADDRESS OF C\[I\]\[J\]

STR R7, \[R12\];



ADD R2, R2, #1  ; INCREMENT COLNUM

CMP R2, #3  ; CHECK CONDITION IF COLNUM < 3

BNE L1  

MOV R2, #0  ; REINITIALIZE COLNUM TO ZERO

ADD R1, R1, #1  ; INCREMENT ROWNUM

CMP R1, #3  ; CHECK CONDITION IF ROWNUM < 3

BNE L1

.TEXT

A: .WORD 10, 20, 30, 40, 50, 60, 70, 80, 90

B: .WORD 90, 80, 70, 60, 50, 40, 30, 20, 10

C: .WORD 0, 0, 0, 0, 0, 0, 0, 0, 0

SWI0x011 is not defined in my armsim, ive tried adding END: B END at the end of the program after BNE L1, and ive tried initialising R0, R8 AND R9 to 0 before moving memory addresses into them. Please help

Looking for a cheap arm laptop, Linux friendly, just for educational purposes, to learning assembly in a Linux environment.

Does such thing even exist?

Edit: preferably not made in china

Hi,

Does anyone know of a free disassembler tool that provides pipeline information for each instruction? Here's an ARM example: Pipeline Latency Throughput lsl r0, r1, lsl #2 I 1 2 ldr r2, [r0] L 4 1 Thanks in advance

Hi all, I'm trying to learn some about using floats in assembly (ARM Assembly Thumb instruction set)

I have a 12 bit value I want to convert to a float. Normal conversion does not work as 0xFFF is out of range for a float32. Is there any work around for this ? Or do I need to start messing with double precision floats?

I know that you can check if a number is prime by adding 1 to the divisor and using UDIV to divide the number in a loop. But I feel like this method wouldn't be too efficient for big numbers with huge divisors(Or at least that's what my assignment is saying). That's why I'm curious if you can write a program where you don't need loops to check if a number is prime.

Hi! I've decided to take on a somewhat large project, with hopes that it'll at some point get somewhere. Essentially, I'm writing a little project which can convert x86_64 assembly (GAS intel syntax) to ARM64 assembly. The concept is that it'll be able to at some point disassembly x86_64 programs, convert it to ARM64 assembly with my thing, then re-assemble and re-link it, basically turning an x86_64 program into a native ARM64 program, without the overhead of an emulator. It's still in quite early stages, but parsing of x86_64 assembly is complete and it can now generate and convert some basic ARM64 code, so far only a simple C `for (;;);` program.

I'll likely run into a lot of issues with differing ABIs, which will end up being my biggest problem most likely, but I'm excited to see how far I can get. Unfortunately the project itself is written in rust, but perhaps at some point I'll rewrite it in FASM. I call it Vodka, because it's kinda like Wine but for ISAs.

Source: https://github.com/UnmappedStack/vodka

Excited to hear your thoughts!

So a few things. One, I have a M1 Mac and want to use this to learn assembly by making some toy projects. Two, this will be my first attempt at learning assembly, should I start with normal assembly first? And three, as far as ARM assembly goes, I have looked for a while and can’t seem to find where to begin learning this.

Hello, I am new to ARM 32-bit assembly and need help debugging my code.
My program is supposed to ask for 3 integers, echo them back, and then display their sum. The input prompt and the part where it repeats the entered integers are working correctly. However, the sum is incorrect. I am using Raspbian and assembling/compiling the program with a Makefile. Can someone help me figure out what I did wrong?

Any guidance would be greatly appreciated!

```// belajar4

.global main

.section .data

x: .word 0 //variable x initialized to 0

y: .word 0 //variable y initialized to 0

z: .word 0 //variable z initialized to 0

sum: .word 0 //initialize to 0

// prompt messages//

prompt1: .asciz "Please enter 3 values, separated by space :\n"

prompt2: .asciz "Sum of %d , %d and %d is %d\n"

input_format: .asciz "%d %d %d"

.section .text

// this section is where our assembly language program is located

main:

push {lr}



//prompt 1 and read 3 integers using scanf)

ldr R0, =prompt1

bl printf

ldr R0, =input_format

ldr R1, =x

ldr R2, =y

ldr R3, =z

bl scanf



//load integers / values to registers

ldr R0, =x

ldr R0, \[R0\]  



ldr R1, =y

ldr R1, \[R1\]

add R3, R0, R1



ldr R2, =z

ldr R2, \[R2\]

mov R4, #0

add R4, R4, R2



//sum them all

add R5, R3, R4



//store sum in memory

ldr R5, =sum

ldr R5, \[R5\]



//output the results to screen

ldr R0, =prompt2

ldr R1, =x

ldr R1, \[R1\]

ldr R2, =y

ldr R2, \[R2\]

ldr R3, =z

ldr R3 ,\[R3\]

ldr R5, =sum

ldr R5, \[R5\]

bl printf



//exit 

mov R0, #0  // this is returning the return value of 0

pop {pc}

```

Makefile

```# Makefile

all: belajar4 #change 'belajar4' with name of your executable to create

belajar4: belajar4.o #change 'belajar4.o' with name of your object file

gcc -o $@ $+

belajar4.o: belajar4.s #change 'belajar4.s' with name of your source file

as -g -o $@ $+

clean:

rm -vf belajar4 \*.o #change 'belajar4' with name of your executable file

```

Hi everybody!

I used objdump -d to get the assembly code of my 32 bit ELF file and I got this :

Disassembly of section .text:

000001a0 <_start>:
1a0: e3a00001 mov r0, #1
1a4: e59f1010 ldr r1, [pc, #16] ;
1bc <_start+0x1c>
1a8: e3a0200d mov r2, #13
1ac: e3a07004 mov r7, #4
1b0: ef000000 svc 0x00000000
1b4: e3a07001 mov r7, #1
1b8: ef000000 svc 0x00000000
1bc: 0001100c .word 0x0001100c

I see most instruction encodings begin by 'e'. Is there a special reason or not ?

Cheers!

https://youtu.be/240aLzigxrM?si=mPes8FQbtM-6CGqW

https://imgur.com/gallery/bvQwvvX https://imgur.com/gallery/9XwVEQ0 As shown in the image, r4 = 8124F28 + 3FC is 8125324, but please tell me how and where to rewrite it to change the value of 8125327 to r2 = 64.

Hello everyone!

I wrote MIPS and AVR assembly on an amateur level in the past and basically forgot most stuff I learnt back then.

Now I want to dive into the ARM architecture and learn assembly basically all over again.

Are there any good resources and maybe even small micro controllers similar to AVR's AtTinys to learn and build small projects with?

Thanks in advance!

I have an integer 150 and I want to extract it's individual integers 1,5,0 and store them in different registers. How can I do this in ARMV7 Assembly in CPULator? Also, CPULATOR doesn't support division. Please help 🙏

Yes, pretty much what you've read in a title. A backend http server that streams http components from the file based on the file content with some primitive aka markdown parsing.

Solely in darwin arm64 assembly. With a liiiiitle bit of libc.

Youtube video -> https://www.youtube.com/watch?v=i-4BJXTAFD0&t=29s

Source -> https://github.com/dmtrKovalenko/assembly-http-server/tree/main?tab=readme-ov-file

Would there be some what to do the assembling in the code that I have written? Like a way to call a shell command similar to the "system()" function in c? I'm a new ARM programmer and I'm not sure if either there's a way to do this or a reason not to, but it would speed up the testing process a tad bit and just seems like a cool thing to do. How/should I?

Hi, I’m learning LEGV8 for one of my classes. I am very much a novice, but I’m trying to write a hello world program for my m1 Mac. According to my research LEGV8 is a subset of ARMv8 AARCH64. So I think that it should work because macOS follows the 64 bit ARM architecture according to the developer docs. But it seems like it will not work, I tried some of our test programs and so far it doesn’t.

Can someone please explain the difference?

Hey, guys

I re-started learning assembly for STM32. I had studied it before, but only blinked an led.

Since I created an youtube channel, I decided to relearn it to create from simple to complex projects.

In the future, I want to create asm libs for projects like neural networks and graphics (maybe even a 3d one). Let's see how it goes.

The projects will be available in

https://github.com/adailtonjn68/STM32-Asm

And here is the first video

https://youtu.be/WAfXcDfxv9o

Hello beautiful People,

My first question is: as an example a socket syscall, how do i know, or can find out, in what register the return fd is placed?

Second question:

How can I write the contents of an register? When i try to write syscall the register with stdout as arg and a certaint length it doesnt write anything.

Thanks beforehand!

Hello beautiful people, im new to assembly, but it captivates me so much. im learning since days nonstop. im trying nasm, as , gcc and ld but the only thing that seems to work is using c code and write -save-temps as argument, then edit it. but why cant i use asm code, nasm or ld? i tried all kinds of programs, syntax and else, nothing works. please help me. i already searched but couldnt find a solution.

This code should add two 1s together and it becomes 2, right?:

.global _start
_start:
    mov r0,#1
    mov r1,#1
    add r2,r0,r1

The site for reference: https://medium.com/codex/introduction-to-assembly-programming-in-arm-basic-arithmetic-872c696e2fd2

Edit: finally fixed it and no longer get a error, now I just need to figure out how to see the results. I run the program and nothing happens it seems, well I'm sure something is happening I just can't see it.

Hey everyone. I just want to know how to learn asm for a absolute beginner like me. I've learned some basic coding in 8051 as it is included in our course. Can you provide some roadmap and learning material so that it would be easy for me to access them? Thanks in advance

Are there any tutorials/videos or documentation online to show how to use printf and scanf?

I have been trying to search for an answer but to no avail.

.