only by entering the kernel, the tick counter will be updated
=> by using this feature, MetalSVM supports only LwIP's raw interface,
because we have no guarantee that the tcpip thread will get computation time
=> no NETCONN & BSD socket support
=> no load balancing support
New features:
- support of kernel tasks in 64bit mode
- support of LwIP in 64bit mode
Missing features in 64bit mode
- user-level support
- APIC support => SMP support
To create a 64bit version of the MetalSVM kernel, the compiler flags “-m64 -mno-red-zone” and the assembler flags “-felf64” has to be used. Please use qemu-system-x86_64 as test platform.
Notice, metalsvm.elf is a 32bit ELF file. However, it contains (beside the startup code) only 64bit code. This is required because GRUB doesn’t boot 64bit ELF kernels. Therefore, for disassembling via objdump the flag “-M x86-64” has to be used.
As seen in some BSD operating systems, you can now push and pop foreground and background colors onto a stack to change the colors you see on the screen whenever kprintf/kputchar is used.
This could become useful if one wants to see kernel space kprintfs in other colors than user space printfs or error messages in red and other debugging purposes.
Beware: This is just a small and dirty hack which protects the colorstack with locks and so on. But on task switching the color will not be switched. That makes different colors for different colors persistent for all the time difficult/impossible. But I considered adding colors to the task structures a bit overdone for a small debugging-help.
[Sorry for those commit-and-pull-back-mails. Forgot that I had this stuff on the master branch while pushing my own branch onto the server.]
