#Piker Monolithic Kernel for the Raspberry Pi

##About This is a kernel I've been working on in some of my spare time for fun. My hope is to create a basic plan9-like operating system.

The name itself is just a portmanteau of "Pi" and "Kernel". I'm studying computer science after all, not creative writing.

Harry.

##Todo list

• Finish memory management
  • Implement paging for user space
• Start handling interrupts
  • Add some basic syscalls
• Run some code in userspace
  • Add contexts
  • Add scheduling
• Implement VFS
  • Load initramfs
  • Interface for virtual files for drivers
• Add some drivers
  • SD driver
  • FAT driver
  • uart driver
• Become self hosted
  • Port newlib/libc
  • Run userspace programs

##Design

###Philosophy The design philosophy is based off of unix, and some of plan9. The core principle is that everything is a file or file system, and that is the universal interface.

###Notes

• Applications/software are packages
• Security
  • Single user system, but have permissions defined per package
  • Packages can only read/write their own data
  • Packages can only access devices if given permission

###Memory Map

####Virtual Memory

--------------------- USERSPACE
0x00000000-0x3FFFFFFF paged for userspace
--------------------- USERSPACE

--------------------- KERNELSPACE
0x40000000-0xBFFFFFFF unmapped
0xC0000000-0xDFFFFFFF raw memory mapping
0xE0000000-0xF1FFFFFF unmapped
0xF2000000-0xF2FFFFFF raw peripheral mapping
0xF3000000-0xFFFFFFFF unmapped
--------------------- KERNELSPACE

####Physical Memory

0x00000000-0x1FFFFFFF raw memory
0x20000000-0x20FFFFFF io memory