Related Work: bootimg, Two Kernel Monte (TKM)

• bootimg

  • allows a userspace program to read a file in and boot a new image via a system call
  • turns VM (paging) off (but not i386-style segmentation)
  • the user buffer (in VM) has to be copied into kernel memory accessible without VM
  • relies on kernel components being in physically contiguous memory
  • 1100 LOC (600 architecture-dependent), some structures (GDT) need to be maintained in sync with kernel
  • can be used with LinuxBIOS
  • thorough permissions checking, ramdisk support

• Two Kernel Monte (TKM)

  • turns off both VM and i386 segmentation
  • builds and internal virtual-to-physical page map (so it can still get to kernel)
  • relies on BIOS to reset hardware (e.g. video card) after reboot
  • cannot be used with LinuxBIOS (because of reliance on the BIOS)

• Both require an external program to boot a new image (LOBOS doesnג€™t)