1. Building your own toolchain
~ Chaitannya Mahatme

2. Overview of ARM architectures.

ARM 7

ARM 9

ARM 11

3. ARM7TDMI

ARM7TDMI
(ARM7+Thumb+Debug+Multiplier+ICE)

This generation introduced the Thumb 16­
bit instruction set
Audio controller in the SEGA Dreamcast

D­Link DSL­604+ Wireless ADSL Router.

iPod ,iRiver

Most of Nokia's mobile phone range.

4. ARM 9

ARM moved from a von Neumann
architecture (Princeton architecture) to a
Harvard architecture with separate
instruction and data bus (and caches),
significantly increasing its potential speed.

Most important change was introduction of
MMU, POSIX complaint OS could be
ported.

All smart phones

5. ARM 11

SIMD instructions which can double
MPEG­4 and audio digital signal
processing algorithm speed

Cache is physically addressed, solving
many cache aliasing problems and
reducing context switch overhead.

TI OMAP2 series processors.

All touch based smart phones.

6. Steps of Cross­Compilation

gcc: Run the cross­compiler on the host
machine to produce assembler files for the
target machine.

as: Assemble the files produced by the
cross­compiler.

ld: Link those files to make an executable.
You can do this either with a linker on the
target machine, or with a cross­linker on
the host machine.

7. Specifing target for your toolchain

arm­linux

Armv4l : This makes support for the ARM
v4 architecture, as used in the StrongARM,
ARM7TDMI, ARM8, ARM9.

Armv5l : This makes support for the ARM
v5 architecture, as used in the XScale and
ARM10.

8. EABI target

arm­eabi

arm­none­eabi

In practice the target name makes almost
no practical difference to the toolchain you

9. Other EABI options

arm­none­gnueabi: this is the name as arm­
none­eabi (specific to GNU compiler)

arm­unknown­eabi: bare metal

arm­linux­eabi: Designed to be used to
build programs with glibc under a Linux
environment. This would what you would
use to build programs for an embeded
linux ARM device.

10. CPU options

arm7, arm7tdmi, arm720t,

arm9', arm9e, arm920, arm920t

arm1136j­s, arm1176jz­s

11. Other configure options

­­enable­interwork This allows for
assembling Thumb and ARM code mixed
into the same binaries (for those chips that
support that)

­­enable­multilib Multilib allows the use of
libraries that are compiled multiple times
for different targets/build types.

12. EABI for Linux

GNU EABI is a new Application Binary
Interface (ABI) for Linux a.k.a Embedded
ABI.

EABI specifies standard conventions for file
formats, data types, register usage, stack
frame organization, and function
parameter passing of an embedded
software program.

13. Why switch to EABI?

Compilers that support the EABI create
object code that is compatible with code
generated by other such compilers, thus
you can link libraries generated with with
object code generated with a different
compiler.

14. 
Allows use of optimized hardfloat
functions with the system's softfloat
libraries

Uses a more efficient syscall convention,
hence faster performance.

Since it's a newly adopted standard, will be
more compatible with future tools.

15. Setting up build envoirnment.

Preferably use virtual box / Vmware.

Create a new user for the installation.

Set up the configure parameters in the
.profile

Create separate dir for build and source.

Set PREFIX dir

16. Compilation process

Binutils

glibc

gcc

gdb

17. Bootstrapping gcc

Install all the dependencies.

The list of dependencies is on gcc.org

Mandatory dependencies are GMP and
MPFR.

The configure option ­­with­newlib tells gcc
we are using newlib (see below) and
­­without­headers tells GCC not to rely on
any C library (standard or runtime) being
present for the target.

18. Installing glibc

Before doing any configuring or compiling,
you must set the C compiler that you’re
using to be your cross­compiler, otherwise
glibc will compile as a horrible mix of ARM
code and native code

Make all­gcc.

Make install­gcc

19. Installing gcc: Part II

Make

Make install

Add compiler to path variable

20. Get more info on
 http://wiki.openarmlab.org/

http://wiki.openarmlab.org/index.php?
title=Building_your_own_toolchain

21. That's all Folks … Thank you