BOOT(3) BOOT(3)
NAME
boot - reboot under program control
SYNOPSIS
bind -a #B /dev
/dev/boot
/dev/kexec
/dev/mem
DESCRIPTION
Boot serves a directory containing three files that control
a reboot of the system. The files can only be opened by the
host owner (see eve(10.2)).
Boot is a write-only file that accepts 4 bytes representing
a kernel address, high-order byte first. The system will
transfer control to that address, which is assumed to be the
start of low-level reboot code. There is no return from the
write on success or failure.
Kexec is a write-only file to which an uncompressed kernel
image can be written, a chunk at a time. When the file is
closed, the system will transfer control to the start of the
image, which again is assumed to be low-level reboot code.
Mem copies data to and from kernel memory, taking the cur-
rent file offset as an address therein.
Boot flushes caches as necessary to ensure that writes to
kernel memory through any of these files will be visible
when subsequently executed as instructions.
SOURCE
/os/port/devboot.c
SEE ALSO
tftp(2), cons(3)
DIAGNOSTICS
Invalid addresses are diagnosed, but otherwise there is no
error return.