Re: [PATCH v4 11/11] doc:bootmenu: add UEFI boot variable and distro boot support

On 3/24/22 14:54, Masahisa Kojima wrote:

The bootmenu enumerates the UEFI boot variable and distro boot (boot_targets) for boot device selection.

Signed-off-by: Masahisa Kojima masahisa.kojima@linaro.org

Newly created in v4

doc/usage/bootmenu.rst | 65 ++++++++++++++++++++++++++++++++++++++++++

In origin/master the file is called doc/usage/cmd/bootmenu.rst.

1 file changed, 65 insertions(+)

diff --git a/doc/usage/bootmenu.rst b/doc/usage/bootmenu.rst index 1f094ad6ed..dc1d22062b 100644 --- a/doc/usage/bootmenu.rst +++ b/doc/usage/bootmenu.rst @@ -93,3 +93,68 @@ When you intend to use the bootmenu on a color frame buffer console, make sure to additionally define::

  CONFIG_CFB_CONSOLE_ANSI=y

+UEFI boot variable enumeration +==============================

+The bootmenu automatically generates the UEFI boot variable("BOOT####")

How do you ensure that those variables that are autogenerated are not saved?

+in order of "BootOrder". When the user selects the UEFI boot +variable entry, bootmenu sets the selected boot variable index +to "BootNext", then call the uefi boot manager with the command +"bootefi bootmgr".

+The bootmenu automatically enumerates the possible bootable +media devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.

+The bootmenu prints the EFI_LOAD_OPTION.Description[] as title +of the entry together with "UEFI" prefix and BOOT#### variable name.

+Example bootmenu is as below::

• *** U-Boot Boot Menu ***

•   UEFI BOOT0000 : mmc0:1
  

•   UEFI BOOT0001 : mmc0:2
  

•   UEFI BOOT0002 : debian
  

•   UEFI BOOT0003 : nvme0:1
  

•   UEFI BOOT0004 : ubuntu
  

•   UEFI BOOT0005 : nvme0:2
  

•   UEFI BOOT0006 : usb0:2
  

+To scan the discoverable devices connected to the buses such as +USB and PCIe prior to bootmenu showing up, CONFIG_PREBOOT can be +used to run the command before showing the bootmenu, i.e.::

• CONFIG_USE_PREBOOT=y
• CONFIG_PREBOOT="pci enum; usb start; scsi scan; nvme scan; virtio scan"

+distro boot command enumeration +===============================

+The bootmenu also automatically generates the entries for +distro boot command. The bootmenu shows the devices in boot_targets +environment variable. +When the user selects the distro boot command entry, the bootmenu +runs the command defined in "bootcmd_xxx" environment variable. +As an example, if user selects "usb0" entry, bootmenu runs the +command defined in "bootcmd_usb0".

+Example boot_targets::

• usb0, scsi0, nvme0, dhcp

+Example bootmenu is as below::

• *** U-Boot Boot Menu ***

•   distro_boot   : usb0
  

•   distro_boot   : scsi0
  

•   distro_boot   : nvme0
  

•   distro_boot   : dhcp
  

+Disable to enter the U-Boot console +===================================

+To improve the product security, U-Boot console can be disabled by::

• CONFIG_CMD_BOOTMENU_ENTER_UBOOT_CONSOLE=n

The man page should have a section 'Configuration' which lists all relevant configuration options for the bootmenu command.