Gentoo: crossdev avr

Cross compile ?

Cross compile is name of build process which produce machine code for different architecture. For example i am embed device developer and i am producing machine code for AVR platform on x86_64 workstation. Effectively i am doing cross compile on x86_64 to AVR target. I am writing source code in C language and partly in assembler.

Why sys-devel/crossdev ?

Because it is Gentoo specific tool to manage necessary software to perform cross compile (e.g. binutils, headers, libraries, and compiler). It is very simple to use so i save some of my time during installation of crossdev environment.

Installation of AVR target

sys-devel/crossdev

I recommend latest version of sys-devel/crossdev so first of all put this ebuild to package.keywords. This package don't have USE flags so it is enough to perform:

emerge crossdev

required configuration

crossdev is using own local portage overlay to build target specific configuration. Following line is necessarily in /etc/make.conf. Of course you can use different location :)

PORTDIR_OVERLAY="/opt/local/portage"

If directory dont exist then create it

mkdir -p /opt/local/portage

! crossdev is using new layout of /etc/portage/package.* . If you don't migrated to this layout then you should to it now. New layout is expecting to /etc/portage/package.keywords/ (and all others) to be a directory and configuration is included in files inside of it. For example for AVR target you can find cross-avr there.

build of target specific code

Just invoke:

crossdev -t avr

And you should see following:

 * crossdev version:      20120721
 * Host Portage ARCH:     amd64
 * Target Portage ARCH:   *
 * Target System:         avr
 * Stage:                 4 (C/C++ compiler)
 * ABIs:                  default

 * binutils:              binutils-[latest]
 * gcc:                   gcc-[latest]
 * libc:                  avr-libc-[latest]

 * CROSSDEV_OVERLAY:      /opt/local/portage
 * PORT_LOGDIR:           /var/log/portage
 * PORTAGE_CONFIGROOT:
 * Portage flags:
!!! WARNING - Cannot auto-configure CHOST avr
!!! You should edit /usr/avr/etc/portage/make.conf
!!! by hand to complete your configuration
 * Log: /var/log/portage/cross-avr-binutils.log
 * Emerging cross-binutils ...                                              [ ok ]
 * Log: /var/log/portage/cross-avr-gcc-stage1.log
 * Emerging cross-gcc-stage1 ...                                            [ ok ]
 * Log: /var/log/portage/cross-avr-avr-libc.log
 * Emerging cross-avr-libc ...                                              [ ok ]
 * Log: /var/log/portage/cross-avr-gcc-stage2.log
 * Emerging cross-gcc-stage2 ...                                            [ ok ]

# eix -c cross-avr/*
[I] cross-avr/avr-libc [1] (1.8.0[?]@03.08.2012): C library for Atmel AVR microcontrollers
[I] cross-avr/binutils [1] (2.22.90[?]@03.08.2012): Tools necessary to build programs
[I] cross-avr/gcc [1] (4.6.3(4.6)[?]@03.08.2012): The GNU Compiler Collection
[N] cross-avr/gdb [1] ((~)7.4.1): GNU debugger
[1] /opt/local/portage
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