LainOS

QEMU Raspberry Pi 3

Layers

1. kernel layer
2. root single user layer
3. userpsace containers layer

In the root layer live system demons. ABI/syscalls is not stable here.

In the user layer live common programms. Only cloudabi is available here.

File Hierarchy

• /bin/ contains executables
• /etc/ configuration files
• /lib/ shared libraries
• /sys/ virtual file system
• /usr/ home directories
• /var/ contains variable files

Memory layout for AArch64

4KB pages + 3 levels	Sizeof	Use
00000000_00000000 - 0000007f_ffffffff	512GB	user
ffffff80_00000000 - ffffffff_ffffffff	512GB	kernel

4KB pages + 4 levels	Sizeof	Use
00000000_00000000 - 0000ffff_ffffffff	256TB	user
ffff0000_00000000 - ffffffff_ffffffff	256TB	kernel

64KB pages + 2 levels	Sizeof	Use
00000000_00000000 - 000003ff_ffffffff	4TB	user
fffffc00_00000000 - ffffffff_ffffffff	4TB	kernel

64KB pages + 3 levels	Sizeof	Use
00000000_00000000 - 0000ffff_ffffffff	256TB	user
ffff0000_00000000 - ffffffff_ffffffff	256TB	kernel

References

• https://web.stanford.edu/class/cs140e/
• https://github.com/shacharr/videocoreiv-qpu-driver
• https://github.com/raspberrypi
• http://jaystation2.maisonikkoku.com/
• https://github.com/NuxiNL/cloudabi
• https://nanomsg.github.io/nng/index.html