Programming in assembler?

Yes. Writing assembly on linux is easy.

You should have an assembler already installed. There are tons of references and howtos on google to get you going.

If you want to do bare metal (no linux or Risc-OS) then it is still possible but a bit more involved.

I assume Pis come with Gcc.

That will assemble OK

Yes, you can. The assembler is included in the C compiler suite, actually it is a part of the binutils package (binary utilities).

The assembler is called 'as' and the linker is 'ld'. However, you may need to call C routines in the standard runtime library, libc, to access operating system facilities.

On x86, at least, "as" is a bit of a pain to use. It is more suited to the output of gcc than for humans to use.

Is "as" as bad on Arm? Is there no more helpful free assembler for the RPi?

It doesn't look too bad, especially if you set up a makefile to manage compilations.

At a glance, its worst feature would seem to be its apparent insistence on using C-compatible entry points and exit methods.

ARM supports their multi-OS assembler armasm but a quick search failed to find a Raspbian package of that name.

compile from source that one.

ARM is a kind of a RISC computer, and they are notoriously hard to program in assembler, but it is not as bad as Sparc or MIPS.

The problem is not in the assembler, but in the machine instruction set. I leave most of the programs to C, and insert embedded assembly when nothing else helps.

Anyway, ARM's instruction set is far more regular than what we have on x86.

!!!!???

You must be joking! I don't know the others but ARM is a dream.

It has an instruction set so short you can memorise it in a day.

Every operation can be performed on any register.

The way you can perform multiple operations on multiple registers in a single instruction is positively inspired!

In order of niceness: (IMHO)

ARM

6809 is a nice instruction set but I've never used it with gusto on a commercial job so if feels wrong to include it. Likewise PowerPC and MIPS4k.

Yes, there will be a small need for assembler, but these days, is there any pressing need to program in assembler for the vast majority of folk? I've looked at some of the code produced by compilers in the last 5 years or so and it's really quite good. Yes, you can shave a little time off it by hand coding, but you would likely get a much greater saving by tuning your algorithms. Use a code profiler to see where the bottlenecks are, and work on those. That's my experience, anyway.

I used 6809 a bit - mainly C, but some asm. Its OK. Not much to it really.

Hey, this is amateur stuff. Assembler is FUN

The 6809 was nice but my favourite was the MOS Tech 6502 - simple, elegant and did everything. Mind you I was brought up on the KDF9 and IBM assemblers so anything was simple after that.

Another Dave

I've done a reasonable amount with 68xxx, 6809 and 6800 MPUs. I'd put them in that order (descending order of niceness, obviously).

Apart from them, my main assembler experience was with ICL 1900 machines. They had a surprisingly nice assembler even if they did lack a stack - it was very regular (you could often guess the mnemonic rather than looking it up) and orthogonal (use any address mode and/or stack reference with any instruction where the combination made programming sense). In short, not dissimilar from the 68xx and 68xxx assemblers.

A 'detail' that seems to pass right over the heads of so many people.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^accumulator

sorry about the obvious typo.

'accumulator' is the 1900 term for register.

of so many people.

Agree, but you sometimes need to qualify 'fun', e.g. I normally classify programming in BASIC as 'not fun' - unless the target system is a STAMP or a PicAxe and the project is mine.

I wrote a BASIC interpreter for fun - does that count? :-)

(It doesn't support in-line assembler though, sorry)

Gordon

I have used 6809 in a commercial project & liked it pretty much an enhanced 6083 which is what we normaly used i also liked the 6502 which was used in many home micros @ the time & quite similar