Questions tagged [assembly]
A low-level programming language providing symbolic representation of machine code.
32
questions
2
votes
1answer
38 views
Does the Raspberry Pi 4's processor support ARM's SHA256 instructions?
According to Wikipedia, every Armv8 processor should support sha256 hashing instructions however /proc/cpuinfo doesn't list it. Could there be a failure to identify the feature by the kernel?
...
0
votes
1answer
26 views
ArmV7 Assembly returning 1 for basic add function call
I'm trying to get into Assembly development for the purposes of better understanding lower level development and I'm doing this with my Raspberry Pi Model 4B. I am going through this tutorial at the ...
0
votes
0answers
68 views
raspberry pi4 mini uart (uart1) not working in barebone code
I'm trying to get the mini UART in a Raspberry Pi 4 (8GB) working. I used the example baremetal kernel from mini uart example and changed the MMIO base in gpio.h to 0xFE000000 for the RPi4. But when I ...
4
votes
1answer
414 views
How do I read the cpuid in aarch64 asm?
In armv7 / 32bit mode I can read the cpuid using
uint32_t arm_cpuid;
__asm__("mrc p15, 0, %0, c0, c0, 0" : "=r"(arm_cpuid));
This gives 0x410FD034 for RPi3 and 0x410FD083 ...
2
votes
1answer
399 views
BCM2835 GPIO Pins vs. Physical Pin Numbers
Good morning.
I am attempting some low-level assembly coding for Raspberry Pi. Using the BCM2835 Peripherals Doc, I have successfully been able to work with the GPIO controller on my RPi Model B rev. ...
2
votes
1answer
37 views
BCM2835 datasheet addressing system
I've been interested in writing a kernel for my old Raspberry Pi for quite a while, and managed to make work some ARM assembly code I found on the famous "Baking Pi" course by the University ...
0
votes
3answers
645 views
How can I run 32-bit compiled assembly code on Rasberry PI 4 B, if possible at all?
I bought the PI 4 B for a university project, as I have to make small 32-bit ARM assembly program. However I realized it too late, that it comes with an aarch64 architecture ARM processor.
I would ...
1
vote
0answers
275 views
Lighting an LED through Pi 4 Model B using Assembly
I have been struggling to light an LED using my raspberry pi 4 model b but have not been able to find a solution.
My assembly code :
.section .init
.globl _start
_start:
mov r0, #0xF0000000
orr r0, ...
4
votes
1answer
61 views
gcc does not compile code that compiles in 'as'
I'm trying to learn assembly using the raspberry pi. I have code that compiles using as but will not compile with gcc. I thought that as was the backend for gcc assembly so I'm confused why it is not ...
1
vote
1answer
88 views
Radio Transmission
Yes, I pretty much a noob, but I was wondering if there is a way to program the Raspberry Pi in Assembly Code to transmit data via radio frequencies (like remote control) between itself and another ...
1
vote
1answer
214 views
Read/Write GPIO
I wrote an assembly code for my Raspberry Pi to read an I/O with a button and switch an LED according to the state of the button. It seems that the I/O with the LED is toggling all the time and I don´...
2
votes
1answer
715 views
bootcode.bin RPi 3
I've been reading this document:
https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/bootflow.md
About the boot process of the Raspberry Pi. I want to make a simple "Hello, ...
3
votes
1answer
211 views
Why does adding a nop or constant break my code?
I am learning the ARM architecture via bare metal programming on the Raspberry Pi 3. I have a booting "kernel" that prints out some info. I have reached a point that I don't understand what is ...
1
vote
2answers
1k views
Is there a program to execute assembly code and check registers?
In our university we have a computer's technology subject in which we have to program in ARM's assembly language.
We have the chance to use a simulator but I was wondering if I was able to execute ...
3
votes
1answer
175 views
OS-less raspberry pi 2 debugging of Assembly language
I have a Raspberry Pi 2 without an OS installed. I have an assignment where I have to create and display some code in assembly language for the Pi 2.
The lab that we have set up at school has ...
0
votes
1answer
190 views
unable to set GPIO 17 as an output by assembly program
I am trying to st GPIO 17 as an output. I am using Pi 2 model B. By searching for the base address of peripherals, I found that it is 0x3F000000. I want to write a code in assembly language, Following ...
3
votes
1answer
273 views
Regarding assembly language programming in Raspberry Pi
I am learning assembly language programming in Raspberry Pi 2 model B. I know about Code::Blocks and gdb. Using assembly language the processor's register can be controlled, but I want to control the ...
1
vote
0answers
260 views
RPi2 bare metal blinker
This is my first assembly program. I have a FAT32 formatted SD card with latest bootcode.bin, start.elf, and a flat binary named kernel7.img converted from the following dumped ELF file:
build/kernal....
2
votes
2answers
1k views
On-board LED connection to GPIO
I stumbled on this tutorial: http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok01.html
Unfortunately this is only made for the B rev2 board, whereas I got a B+ board and the board setup is ...
3
votes
1answer
568 views
Disassemble i386 in Raspbian?
I want to disassemble i386 machine instructions into human readable text in Raspbian.
I am a rookie Linux user and don't know the configuration of installed tools, but from what I understand I need ...
2
votes
1answer
954 views
Windows IoT Core GpioController - assembly 'Windows' causes a cycle
I am trying my new Raspberry Pi with Windows 10 IoT Core.
I have fallowed the steps of the installations and cofigurations, and every thing was fine until I've got to Blanky tutorial
http://ms-iot....
0
votes
1answer
74 views
Baking Pi OK05 - Why "ldr" twice to make the pattern work?
I'm carefully following Baking Pi with my model B, making sure I fully understand everything going on. I am now at lesson 5, to flash the SOS Morse code. It works fine, but I am curious why it needs ...
1
vote
2answers
2k views
Pi 2 CPU Documentation
I'm interested in processor architecture, and assembly programming, but I can't seem to find any documentation, or even the datasheet on the CPU of the Pi 2 (BCM2836). The document I'm looking for ...
3
votes
1answer
805 views
Baking Pi Lesson 02 does not work on B+
I would like to comprehend lesson 2 of Baking Pi, but I am not able to get the LED blinking.
I am using Windows and have installed Cygwin and the ARM tool chain. As explained in the requirements, I ...
3
votes
1answer
809 views
ASM - how do I write graphics straight to the screen
I have some old RISC OS assembly programmes I wrote a few years back and I want to port them to Raspberry Pi.
I ran Mode 28 and wrote output directly to the screen using the memory address where v-...
2
votes
0answers
2k views
Assembly - set gpio as input
I have 2 leds and one button.
both green and yellow led off when booting from card.
When the button is pressed, i want to turn green led off and yellow led on.
However, I have to write assembly. I ...
1
vote
0answers
144 views
Memory addresses
I am writing an assembly program, assembling it and replacing the kernel.img file on a SD card with raspbian installed on it.
Will the memory address of the first instruction be zero? Either because ...
2
votes
3answers
3k views
Assembly code on Raspberry Pi
What's the file extension for assembly code? Can it even be written by a text editor?
My plan was to use nano to write the program (for syntax highlighting), so would that work? If not, what do I ...
2
votes
1answer
711 views
Run program on Baking Pi ARM ASM OS
I am following the Baking Pi Raspberry Pi ASM OS tutorial here, and I thought that it would be cool if I could create a compiler/runner for like, BASIC or a language I create. I don't have the skill ...
0
votes
2answers
2k views
Kernel module assembly output
I compiled the kernel modules written in C directly on my Raspberry Pi using this Makefile:
obj-m := HelloWorld.o
all:
$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
...
20
votes
5answers
26k views
Write an OS for Raspberry Pi in C
I already found the Baking Pi tutorials, but they only use assembly language. I followed the first lessons, but I am already wondering how to use C instead. I mean, there is a reason they invented ...
1
vote
1answer
453 views
Assembling Thumb on Rasparian
Has anyone been successful in assembling, compiling and running thumb or thumb-2 on Rasparian. Here is an example of my assembly code:
.text
.global main
.code 16
main:
MOV r3,#1
finish:
...
