3 9bootfat, 9bootiso, 9bootpxe, bootia32.efi, bootx64.efi, efiboot.fat \- PC bootloader for FAT, ISO and PXE network booting
5 Started by PC BIOS/EFI 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
74 Boot parameters are read from
77 With a PXE capable BIOS and network card one can download
79 and boot the kernel from a TFTP server (see
83 for details). Once started,
87 or, if this file is not present,
89 from the tftp server, where
91 is the MAC address of the client's network card
92 in lower case hex, and uses this as its
96 EFI firmware looks for the files
102 in the boot media and executes them.
103 For local disk media, these files are located in the directory
107 formated boot partition.
110 media, the boot partition is provided
119 In the network boot case, the
123 files are used as the
127 Once started, the boot media
133 configuration is read from from it in the same way as
155 .BR /sys/src/boot/efi
163 9boot first appeared in 9front (April, 2011).
164 EFI support first appeared in 9front (Oct, 2014).