Sortbootorder

This repository contains source code of sortbootorder payload that sorts and saves boot order in flash.

Theory of operation

Example menu view

Exact list may be different, depending on BIOS release version.

a USB 1 / USB 2 SS and HS
b SDCARD
c mSATA
d SATA
e mPCIe1 SATA1 and SATA2
f iPXE (disabled)

r Restore boot order defaults
n Network/PXE boot - Currently Disabled
t Serial console - Currently Enabled
l Legacy console redirection - Currently Enabled
u USB boot - Currently Enabled
h EHCI0 controller - Currently Disabled
o UART C - Currently Enabled
p UART D - Currently Enabled
x Exit setup without save
s Save configuration and exit

First part of the list is used to set boot device priorities. Second part of the list is used to enable/disable specific settings. Those information are stored in bootorder file, which is written back to flash after hitting s key.

bootorder file

Sortbootorder manages bootorder file which is initially shipped from coreboot repository This is binary file that has to be 4096 bytes long in order to entirely fill one FLASH sector.

Relevant content of this file may look like this:

/pci@i0cf8/usb@10/usb-*@1
/pci@i0cf8/usb@10/usb-*@2
/pci@i0cf8/usb@10/usb-*@3
/pci@i0cf8/usb@10/usb-*@4
/pci@i0cf8/*@14,7
/pci@i0cf8/*@11/drive@0/disk@0
/pci@i0cf8/*@11/drive@1/disk@0
/pci@i0cf8/pci-bridge@2,5/*@0/drive@0/disk@0
/pci@i0cf8/pci-bridge@2,5/*@0/drive@1/disk@0
/rom@genroms/pxe.rom
pxen0
scon1
usben1

Rest of this file is filled with characters to meet that 4096 bytes requirement.

When device is attached and detected by SeaBIOS, then SeaBIOS begins to check if such device node is written into bootorder file. If it is, it gains priority according to it's place on the list. You can refer to SeaBIOS documentation for more insight.

bootorder_map file

bootorder_map file is used to match device letter and description with corresponding node from bootorder file.

Default settings

• Bootorder list default settings:

  a USB 1 / USB 2 SS and HS
  b SDCARD
  c mSATA
  d SATA
  e mPCIe1 SATA1 and SATA2
  f iPXE
  

• Rest of default settings:

  Network/PXE boot - Disabled
  Serial console - Enabled
  Legacy console redirection - Enabled
  USB boot - Enabled
  EHCI0 controller - Disabled
  UART C - Enabled
  UART D - Enabled
  

Default bootorder list settings are taken from bootorder_def file. They can be restored by hitting r key. It only restores to default boot list order, not other specific settings such as USB enable or serial console enable.

Building

Recent automated building process

Please follow release process document to build complete coreboot binary, already including SeaBIOS and other payloads (such us sortbootorder).