Newbie want to learn Assembly on Raspberry Pi B 2.0 running Debian

Hi and wecome, you're in the right place

Welcome on the community

Hi krynobosman and welcome to the community!

Though I don't have a RasPi myself and can't recommend any books, I'm programming in assembly language myself on the Cortex-M.

I have a CubieBoard2 running Cubian Linux, which I use for testing Cortex-M code (it can be compiled and run on the Cortex-A), thus my environment would be similar to yours.

What I use is GCC-4.7.2 (the default compiler for Cubian), and I've made a few tests in assembly language. I run these programs on the command-line (via SSH).

First of all, I recommend that you go to the ARM Information Center and download the ARMv7AR Reference Manual.

Because the Cortex-M User Guides are so easy/quick to read, I also suggest that you take a look at the Cortex-M4 instruction set, because it gives you a quick overview of each instruction. Also the Table of Processor Instructions might be interesting. This should give you a quick start.

-But of course, your Cortex-A7 based Raspberry Pi can do much more than the Cortex-M4, so you'll also be interested in GPU and vector programming.

Since I don't know any books myself, I'll let other people recommend books; you may want to follow people like peterharris, daith, jyiu and chrisshore (though Joseph is a Cortex-M expert, he oftens answers questions about or related to assembly language, and his answers gives a good understanding on how the ARM architecture works).

In addition, I'd like to post a small quick-start on how you can compile a minimal assembly language program on the command-line.

This example shows you a few things; including how to build without writing a Makefile, how to call functions written in assembly language from C and how to call C functions from assembly language (including that parameters are passed in registers):

File: 'b'. After saving, issue a 'chmod 755 b' command:

#!/bin/bash

DEVICE="cortex-a7"
DEV_FLAGS="-mcpu=${DEVICE} -mtune=${DEVICE}"
FLAGS="${DEV_FLAGS} -mthumb"
ASFLAGS="${FLAGS} -Wa,-mimplicit-it=always -x assembler-with-cpp"
GCFLAGS="${FLAGS} -mthumb-interwork -Wall -Wextra -Wimplicit -Wcast-align -Wpointer-arith -Wredundant-decls -Wshadow -Wcast-qual -Wcast-align -Wnested-externs --std=gnu99"
LDFLAGS="${FLAGS} -lc -lm -lgcc -lstdc++"

gcc ${GCFLAGS} -c main.c -o main.o && \
gcc ${ASFLAGS} -c example.s -o example.o && \
g++ ${LDFLAGS} *.o -o example && \
./example

File: 'main.c':

#include <stdint.h>
#include <stdio.h>

void example(void);

int main(int argc, const char *argv[])
{
  example();
  return(0);
}

File: 'example.s'

                    .syntax             unified             /* use modern syntax */
                    .text                                   /* place our code in the text-section */

                    .func               example             /* (for debugging info) */
                    .global             example             /* make 'example' symbol global */
                    .type               example,%function   /* 'example' is a function */
                    .thumb_func                             /* a function, which uses thumb instructions */

example:            push                {r4-r7,lr}          /* save r4-r7 and return address */
                    ldr                 r0,=string          /* point to format string */
                    movs                r1,#1               /* parameter 1 value */
                    movw                r2,#777             /* parameter 2 value */
                    bl                  printf              /* call printf */
                    pop                 {r4-r7,pc}          /* restore saved registers and return */
                    .pool                                   /* allow the assembler to place a literal pool here */
                    .size               example,.-example   /* tell linker how large this function is */
string:             .asciz              "Value 1:%ld \nValue 2:%ld\n"     /* a format-string for printf */

                    .endfunc                                /* (for debugging info) */

To build, just type ./b on the command-line. The files should then be compiled and executed.

Hi krynobosman,

This is not an exact answer but close to the kind of book that you are looking for, Raspberry Pi ASSEMBLY LANGUAGE RASPBIAN BEGINNERS by BRUCE SMITH.

It's for RASPBIAN and only available in print. It's more than a year since you opened this discussion but I hope my reply will also be helpful to others who will find themselves in your context.

Regards,

Goodwin