This is one part of the UVA-OS class (CS4414/CS6456).

OVERVIEW | LAB1 | LAB2 | LAB3 | LAB4 | LAB5

The OS now includes file abstraction and file systems. Userspace is built independently of the kernel and executed via exec(). The OS implements more I/O drivers, notably USB keyboard and sound device, exposing them via /proc and /dev to userspace. Userspace comprises a simplified libc and applications including Mario, slider, shell, and a sound tester.

This OS introduces virtual memory and user/kernel separation. It provides syscalls and can run one or multiple "Mario" applications concurrently in userspace.

✅ File abstractions

✅ A filesystem (xv6)

✅ procfs, devfs

✅ More syscalls: file related (open/close/read/write/lseek...)

✅ USB keyboard (can control Mario)

✅ Sound device

⛔ No FAT32 ⛔ No actual disks ⛔ No multicore

The "simple" userspace contains a minimalist "libc".

• Support filesystem (xv6).
• Programs will be built & linked as *.elf binaries, and packed into a filesystem image (mkfs.c) which is then packed into kernel8.img as a ramdisk.

libc-simple/
A minimalist "libc" that provides basic C functions and syscall stubs.

LiteNES/
The NES emulator that can load ROMs (e.g., Kung Fu, md5sum: 27e5c62c6c) from the filesystem (e.g., ramdisk). Executable: nes.

sysmon/
System resource monitor.

buzz.c
Plays raw waveform included in the C header; cannot load encoded files.

sh.c
Shell.

slider.c
Slide (static images) player.

(other *.c)
Command-line utilities.

mkfs.c
An x86 program for packing all userspace into a filesystem image, which goes to the ramdisk image included in kernel8.img.

export PLAT=rpi3qemu

export PLAT=rpi3

(One time): Prepare the SD card

https://github.com/fxlin/uva-os-main/tree/main/make-sd

Copy the kernel image kernel8.img to the partition named bootfs and boot.