bootsvc is (typically) the first program loaded by usermode (contrast with
userboot, which is loaded by the kernel). bootsvc provides
several system services:
- A filesystem service with the contents of the bootfs (/boot)
- A loader service that loads from that bootfs
After preparing these services, it launches one program from the bootfs. The
program may be selected with a kernel command line argument
bootsvc.next (this default to bin/devmgr currently). The launched program
is provided with the bootfs mounted at /boot and the loader service. The
kernel command line arguments are provided to it via envp. See the
documentation in system/core/bootsvc/main.cpp:LaunchNextProcess() for more
details.