手機 - N900 - PostMarketOS - Unpack uInitrd-postmarketos-stable

參考資訊：
http://h-wrt.com/en/mini-how-to/uInitrd

方式如下：

$ file uInitrd-postmarketos-stable
    uInitrd-postmarketos-stable: u-boot legacy uImage, uInitrd, Linux/ARM, RAMDisk Image (Not compressed), 6172013 bytes, Thu Nov  7 06:37:51 2019, Load Address: 0x00000000, Entry Point: 0x00000000, Header CRC: 0xA31D3D89, Data CRC: 0x36BB5FB5

$ mkimage -l uInitrd-postmarketos-stable 
    Image Name:   uInitrd
    Created:      Thu Nov  7 01:37:51 2019
    Image Type:   ARM Linux RAMDisk Image (uncompressed)
    Data Size:    6172013 Bytes = 6027.36 kB = 5.89 MB
    Load Address: 00000000
    Entry Point:  00000000

$ dd if=uInitrd-postmarketos-stable of=initrd skip=64 bs=1
$ file initrd 
    initrd: gzip compressed data, max compression, from Unix

$ mv initrd initrd.gz
$ gunzip initrd.gz
$ file initrd 
    initrd: ASCII cpio archive (SVR4 with no CRC)

$ cpio -i -F initrd