[crossdev][Gentoo] use crossdev to build own toolchain

Install crossdev
emerge sys-devel/crossdev

Build the folder of portage
mkdir -p /usr/local/portage/

crossdev –ov-output /usr/local/portage/ -S -t armv7a-hardfloat-linux-gnueabi

 * crossdev version:      20150602
 * Host Portage ARCH:     amd64
 * Target Portage ARCH:   arm
 * Target System:         armv7a-hardfloat-linux-gnueabi
 * Stage:                 4 (C/C++ compiler)
 * ABIs:                  

 * binutils:              binutils-[stable]
 * gcc:                   gcc-[stable]
 * headers:               linux-headers-[stable]
 * libc:                  glibc-[stable]

 * CROSSDEV_OVERLAY:      /usr/local/portage/
 * PORT_LOGDIR:           /var/log/portage
 * PORTAGE_CONFIGROOT:    
 * Portage flags:         

Reference:

• 在 Gentoo Linux 下使用 crossdev 建立自己的 toolchain

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Meet Problem
Q:
* You need to specify an output overlay. Please use –ov-output, or consult
* https://wiki.gentoo.org/wiki/Overlay/Local_overlay for more details.


A:
add following parameter to crossdev -S -t armv7a-hardfloat-linux-gnueabi
–ov-output /usr/local/portage/
Reference:

• 在gentoo上安装 mips64el-st-linux-gnu-交叉编译工具链