[[PageOutline]]

 * [http://wiki.openwrt.org/about/toolchain OpenWrt Buildroot – About - OpenWrt Wiki]
 * [http://d.hatena.ne.jp/sdkt4a/20080814/1218655463 OpenWrtのクロスコンパイル環境をDebianに構築してhello,worldするよ！ - sdkt4aの日記]
 * [https://wiki.projectmeshnet.org/Build_for_OpenWRT Build for OpenWRT - meshwiki]
 * [http://d.hatena.ne.jp/nyaxt/20120212#1329014697 FON2100E openwrt backfire 10.03.1用クロスコンパイル環境の構築 2012-02-12 - nyaxtのPC作業ログ]

 = buildroot =
 * Ubuntu 12.04 LTS x86_64

 * mitty@precise:~$ sudo aptitude install subversion build-essential libncurses5-dev zlib1g-dev gawk gcc-multilib flex git-core gettext libssl-dev xsltproc bison

 * mitty@precise:~$ mkdir openwrt

 * mitty@precise:~/openwrt$ svn co svn://svn.openwrt.org/openwrt/trunk/
{{{
(snip)

 U   trunk
Checked out revision 32026.
}}}

 * mitty@precise:~/openwrt/trunk$ wget http://downloads.openwrt.org/snapshots/trunk/ar71xx/config
 * mitty@precise:~/openwrt$ cp config trunk/.config

 * mitty@precise:~/openwrt/trunk$ make prereq
{{{
Collecting package info: done
Collecting target info: done
Checking 'working-make'... ok.
Checking 'case-sensitive-fs'... ok.
Checking 'getopt'... ok.
Checking 'fileutils'... ok.
Checking 'working-gcc'... ok.
Checking 'working-g++'... ok.
Checking 'ncurses'... ok.
Checking 'zlib'... ok.
Checking 'gawk'... ok.
Checking 'flex'... ok.
Checking 'unzip'... ok.
Checking 'bzip2'... ok.
Checking 'patch'... ok.
Checking 'perl'... ok.
Checking 'python'... ok.
Checking 'wget'... ok.
Checking 'git'... ok.
Checking 'gnutar'... ok.
Checking 'svn'... ok.
Checking 'gnu-find'... ok.
Checking 'getopt-extended'... ok.
Checking 'non-root'... ok.
}}}

 * mitty@precise:~/openwrt/trunk$ make -j 5 V=99 2>&1 | tee build.log | grep -i error
{{{
(snip)

make[2]: [package/rootfs-prepare] Error 2 (ignored)
Compression errors: 0
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wpe72.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
Compression errors: 0
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wp543.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
[mkmylofw] Error: file /home/mitty/openwrt/trunk/build_dir/linux-ar71xx_generic/tmp/vmlinux-wpe72.bin.lzma is too big
make[5]: [install] Error 1 (ignored)
make[3]: [/home/mitty/openwrt/trunk/bin/ar71xx/OpenWrt-ImageBuilder-ar71xx_generic-for-Linux-x86_64.tar.bz2] Error 1 (ignored)
make[3]: [/home/mitty/openwrt/trunk/bin/ar71xx/OpenWrt-ImageBuilder-ar71xx_generic-for-Linux-x86_64.tar.bz2] Error 1 (ignored)
}}}

 * mitty@precise:~/openwrt$ cat > test.c
{{{#!cc
#include <stdio.h>

int main(void) {
        printf("char        -> %ld\n", sizeof(char));
        printf("short       -> %ld\n", sizeof(short));
        printf("int         -> %ld\n", sizeof(int));
        printf("long        -> %ld\n", sizeof(long));
        printf("long long   -> %ld\n", sizeof(long long));
        printf("float       -> %ld\n", sizeof(float));
        printf("double      -> %ld\n", sizeof(double));
        printf("long double -> %ld\n", sizeof(long double));

        return 0;
}
}}}
 * mitty@precise:~/openwrt$ gcc test.c -o test.x86
 * mitty@precise:~/openwrt$ ./trunk/staging_dir/toolchain-mips_r2_gcc-4.6-linaro_uClibc-0.9.33.2/bin/mips-openwrt-linux-gcc test.c -o test
{{{
mips-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
mips-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
mips-openwrt-linux-gcc: warning: environment variable 'STAGING_DIR' not defined
}}}

 * mitty@precise:~/openwrt$ file test test.x86
{{{
test:     ELF 32-bit MSB executable, MIPS, MIPS32 rel2 version 1, dynamically linked (uses shared libs), with unknown capability 0x41000000 = 0xf676e75, with unknown capability 0x10000 = 0x70403, not stripped
test.x86: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0x53177842cbc614b1f4c71bae24df294892906443, not stripped
}}}

 * mitty@precise:~/openwrt$ ./test.x86
{{{
char        -> 1
short       -> 2
int         -> 4
long        -> 8
long long   -> 8
float       -> 4
double      -> 8
long double -> 16
}}}

 * mitty@precise:~/openwrt$ ./test
{{{
bash: ./test: cannot execute binary file
}}}

 * mitty@starseed:~$ uname -a
{{{
Linux starseed 3.3.6 #1 Thu May 17 02:19:20 PDT 2012 mips GNU/Linux
}}}
 * mitty@starseed:~$ ./test
{{{
char        -> 1
short       -> 2
int         -> 4
long        -> 4
long long   -> 8
float       -> 4
double      -> 8
long double -> 8
}}}

 = build others =

 == zlib ==
 * [http://www.crosscompile.org/static/pages/ZLib.html How to Cross Compile Zlib Compression Library - Step by Step Guide (crosscompile.org)]

 == openssl ==
 * [http://www.crosscompile.org/static/pages/OpenSSL.html How to Cross Compile OpenSSL a Step by Step Guide (crosscompile.org)]