EwokOS

.Author

Misa.Z [email protected]

.About

A microkernel OS for learning operating system. versatilepb / raspi1,2,3 ported well, raspi4 todo....
-mmu
-multi processes
-multi thread
-ipc
-virtual fs service(everythig is a file)
-very simple ramdisk for initrd
-framebuffer device service for graphics
-uart device service
-SD card

.Environment & Tools

QEMU: 
    brew install glib
    brew install pixman
    brew install pkg-config
    download modified qemu-4.2.0 from https://github.com/MisaZhu/qemu_raspi
    ./configure --enable-kvm --enable-hax --target-list=arm-softmmu
    make and make install
Linux:  
    Ubuntu Linux 16.04 with "libglib2.0-dev","libpixman-1-dev","libsdl2-dev","gcc-arm-none-eabi","gdb-arm-none-eabi" or "gdb-multiarch","fuseext2"
    installed(can install by "apt")

Mac OSX(with brew installed):
    brew tap PX4/homebrew-px4
    brew install gcc-arm-none-eabi-49
    (set the right PATH environment after installed)
    download usb to ttl driver https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
    brew install python
    pip install pyserial
How to create/mount ext2 image in macosx
    ===============prepair================
    brew install e2fsprogs
    brew cask install osxfuse
    brew install libtool 
    brew install autoconf
    brew install automake
(download https://github.com/alperakcan/fuse-ext2)
./autogen.sh
CFLAGS="-idirafter/opt/gnu/include -idirafter/usr/local/include/osxfuse/ -idirafter/$(brew --prefix e2fsprogs)/include" LDFLAGS="-L/usr/local/opt/glib -L/usr/local/lib -L$(brew --prefix e2fsprogs)/lib" ./configure
sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
make
sudo make install
=================example==============
dd if=/dev/zero of=img bs=1024 count=16384
mke2fs img
mkdir -p tmp
fuse-ext2 -o force,rw+ img tmp
(copy files)
umount ./tmp
rm -r tmp

.tty debug

install miniterm.py
miniterm.py /dev/xxxUSBTTY 115200

.make and run

"cd system; make/make full(with XGUI)":
  build EwokOS rootfs apps and sd file system.
"cd kernel/build/{arch}; make":
  build EwokOS kernel image.
"make run":
  run EwokOS;
"make debug":
  run EwokOS at debug server-mode.
"make gdb":
  debug EwokOS (debug client-mode).

.commands

Most of commands are in 'rootfs/sbin' directory, like:
ls, ps, pwd, test ......

.Source code read-guide Tips: Don't fall in love with assembly too much;).

. Kernel init memory map

PhyMem        VMem         Desc
----------------------------------------------------
0x00000000    0xFFFF0000   interrupt table
0x00008000    0x80008000   Kernel start (load to)
***           ***          (_init_stack, _irq_stack, _startup_page_dir)
***           ***          Kernel end, Kernel PageDir Table start
+16KB         +16KB        Kernel PageDir Table end.
+128KB        +128KB        kernel malloc base
+32M           +32M          kernel malloc end (size=2M).
......
physical ram top           Share memory start base               
......
MMIO_BASE_PHY MMIO_BASE    MMIO base (arch)
......