OpenWrt中的FEATURES:=broken jffs2

target/linux/goldfish中有：

FEATURES:=broken

或者其他的如：

FEATURES:=jffs2 squashfs

scripts/metadata.pl中有 ?关于FEATURES的定义：

1 利用这个perl脚本可以把下面的如jffs2，broken这些转化为BROKEN，USES_JFFS2这些实际的CONFIG_参数。

2 同时注意区别depends BROKEN ?和?select USES_JFFS2，这也就是为什么FEATURES:=broken的效果和FEATURES:=jffs2不一样的原因！

sub target_config_features(@) {
	my $ret;

	while ($_ = shift @_) {
		/broken/ and $ret .= "tdepends BROKENn";
		/audio/ and $ret .= "tselect AUDIO_SUPPORTn";
		/display/ and $ret .= "tselect DISPLAY_SUPPORTn";
		/gpio/ and $ret .= "tselect GPIO_SUPPORTn";
		/pci/ and $ret .= "tselect PCI_SUPPORTn";
		/pcie/ and $ret .= "tselect PCIE_SUPPORTn";
		/usb/ and $ret .= "tselect USB_SUPPORTn";
		/pcmcia/ and $ret .= "tselect PCMCIA_SUPPORTn";
		/squashfs/ and $ret .= "tselect USES_SQUASHFSn";
		/jffs2/ and $ret .= "tselect USES_JFFS2n";
		/ext2/ and $ret .= "tselect USES_EXT2n";
		/targz/ and $ret .= "tselect USES_TARGZn";
		/cpiogz/ and $ret .= "tselect USES_CPIOGZn";
		/ubifs/ and $ret .= "tselect USES_UBIFSn";
		/fpu/ and $ret .= "tselect HAS_FPUn";
		/ramdisk/ and $ret .= "tselect USES_INITRAMFSn";
		/powerpc64/ and $ret .= "tselect powerpc64n";
		/nommu/ and $ret .= "tselect NOMMUn";
	}
	return $ret;
}