raspi-as

Assembly projects on Raspberry Pi 4 model B

blinky_42

Blinky on built-in led

blinky_17

Blinky using a GPIO (17 randomly chosen)

Connect a led with 1k resistor in series from GPIO17 to ground

uart_write

UART peripheral used to write strings to usb via TTL

uart_read

UART peripheral used to read strings from usb via TTL

Uart reads are use to control the built-in LED.

pwd_blinky

Control an led with pwd peripheral

pwd_motor

Control a motor with pwd peripheral

To compile and boot

First, format an SD card in FAT32 format and name it "BOOT." To make this card bootable, a few more files are required:

bcm2711-rpi-4-b.dtb
bootcode.bin
start.elf
start4.elf

These can be downloaded from https://github.com/raspberrypi/firmware/tree/master/boot

Generate program with

arm-none-eabi-as blinky.s -o blinky.o
arm-none-eabi-ld --no-undefined blinky.o -o blinky.elf
arm-none-eabi-objcopy blinky.elf -O binary kernel7l.img

You can now copy your generated "kernel7i.img" file to the boot partition of the SD card. Now insert the card into the Raspberry Pi and boot the Raspberry Pi