EwokOS
.Author
Misa.Z misa.zhu@gmail.com
.About
A microkernel OS for learning operating system. versatilepb ported well, raspi2 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
Linux:
Ubuntu Linux 16.04 with "qemu-system-arm","gcc-arm-none-eabi","gdb-arm-none-eabi"
installed(can install by "apt")
Mac OSX(with brew installed):
brew tap PX4/homebrew-px4
brew install gcc-arm-none-eabi-49
brew install qemu
(set the right PATH environment after installed)
.make and run
"cd rootfs; make; ./mkfs.sh":
build EwokOS root filesystem.
"cd kernel; make versatilepb_defconfig; make":
build EwokOS kernel image.
"cd kernel; make run":
run EwokOS;
"qemu-system-arm -kernel build/EwokOS.bin -serial mon:stdio -sd ../rootfs/rootfs.ext2"
boot kernel file and mount SD card.
"cd kernel; make debug":
run EwokOS at debug server-mode.
"cd kernel; 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
kernel/asm/boot.S
kernel/src/mm/kalloc.c
kernel/src/mm/mmu.c
kernel/src/mm/trunkmalloc.c
kernel/src/mm/kmalloc.c
kernel/src/proc.c
kernel/src/sheduler.c
kernel/src/syscalls.c
kernel/src/mm/shm.c
kernel/src/ipc.c
rootfs/lib/src/stdlib.c
rootfs/lib/src/unistd.c
rootfs/lib/src/ipc.c
rootfs/lib/src/shm.c
rootfs/sbin/init/init.c
rootfs/sbin/vfsd/vfsd.c
rootfs/dev/initfs/initfs.c
rootfs/dev/fbd/fbd.c
rootfs/dev/ttyd/ttyd.c
rootfs/sbin/shell/shell.c
Tips: Don't fall in love with assembly too much;).
. Kernel init memory map
PhyMem VMem Desc
----------------------------------------------------
0x00000000 0xFFFF0000 interrupt table
0x00010000 0x80010000 Kernel start (load to)
*** *** (_init_stack, _irq_stack, _startup_page_dir)
*** *** Kernel end, Kernel PageDir Table start
+16KB +16KB Kernel PageDir Table end.
+32KB +32KB kernel malloc base
+2M +2M kernel malloc end (size=2M).
......
0x08000000 0x08000000 init ramdisk base (load initrd to)
0x08020000 0x08020000 init ramdisk end (size=2M).
......
physical ram top Share memory start base
......
MMIO_BASE_PHY MMIO_BASE MMIO base (arch)
......