3 9bootfat, 9bootiso, 9bootpxe \- PC bootloader for FAT, ISO and PXE network booting
5 Started by PC BIOS or chainloaded by partition bootsector
7 9boot is the bootloader used on PCs to start the Plan 9 kernel.
8 Its task is to read and parse the
10 configuration file, gather some basic system information like
11 the amount of usable system memory, do some basic system
12 initialization and load the kernel from the boot media into memory.
14 After reading the configuration, the loader will automatically
15 attempt to boot the kernel that was specified by the
17 parameter. If there is no such parameter, a key
18 gets pressed on the keyboard or the kernel file was not
19 found then the loader enters the interactive
22 The syntax of the boot console is the same as in the
26 pairs setting boot parameters. In addition a few command
27 words are recognized that are intended for interactive use:
30 can be used to remove parameters from the configuration.
33 is specified, the first parameter that matches the prefix
36 argument is omitted, the whole configuration will be reset.
39 displays the current configuration in memory.
42 will return to the console prompt after processing the
43 configuration file preventing automatic boot.
46 will end the console and attempt booting the kernel.
48 There are many ways to boot a PC so
50 was split into a number of distinct programs one for each boot
53 When booting Plan 9 from a harddisk or USB pen drive, a
56 is used to store the kernel and
58 configuration. Due to size limitations, instead of loading
59 the kernel directly, the bootsector
61 of the FAT partition loads
62 a 2nd stage bootloader
64 from the root directory of the filesystem.
66 Booting from CD-ROM requires only the
68 bootloader to be included in the ISO-9660 image under
70 set as a non-emulation bootblock (see
72 Boot parameters are read from
75 With a PXE capable BIOS and network card one can download
77 and boot the kernel from a TFTP server (see
81 for details). Once started,
85 or, if this file is not present,
87 from the tftp server, where
89 is the MAC address of the client's network card
90 in lower case hex, and uses this as its