Kojima-san,
On Mon, May 16, 2022 at 08:00:41PM +0900, Masahisa Kojima wrote:
The bootmenu enumerates the UEFI boot options for boot device selection.
This commit adds the description how the UEFI boot work in bootmenu. This commit also adds "Synopsis", "Description" and "Configuration" sections to follow the U-Boot command documentation format.
Signed-off-by: Masahisa Kojima masahisa.kojima@linaro.org
Changes in v6:
- remove distro boot related contents because the distro boot
support in bootmenu is dropped
? I rejected it in my comment. I don't think we have enough consensus yet.
- update uefi entry example
- add [delay] argument of bootmenu command
- add description to enable uefi boot entry
Changes in v5:
- follow the cmd documentation format same as other command, add "Synopsis", "Description" add "Configuration" sections
Newly created in v4
doc/usage/cmd/bootmenu.rst | 55 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+)
diff --git a/doc/usage/cmd/bootmenu.rst b/doc/usage/cmd/bootmenu.rst index 9430f8c9aa..6b154d9655 100644 --- a/doc/usage/cmd/bootmenu.rst +++ b/doc/usage/cmd/bootmenu.rst @@ -4,6 +4,16 @@ bootmenu command ================
+Synopsis +--------
+::
- bootmenu [delay]
+Description +-----------
The "bootmenu" command uses U-Boot menu interfaces and provides a simple mechanism for creating menus with different boot items. The cursor keys "Up" and "Down" are used for navigation through @@ -79,6 +89,35 @@ The above example will be rendered as below:: The selected menu entry will be highlighted - it will have inverted background and text colors.
+UEFI boot variable enumeration +''''''''''''''''''''''''''''''
+The bootmenu automatically generates the UEFI boot variable("BOOT####") +in order of "BootOrder".
To be strict, the bootmenu command *does not* create UEFI boot variables (except ones for removable media). So, I would suggest you to modify the text like:
If enabled, the bootmenu command will automatically generate and add UEFI-related boot menu entries for * possible bootable media with default file names * user-defined UEFI boot options
Then,
+The bootmenu automatically enumerates the possible bootable +media devices supporting EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. +This auto generated entry is named as "<interface> <devnum>:<part>" format. +(e.g. "usb 0:1")
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".
+Example bootmenu is as below::
- *** U-Boot Boot Menu ***
mmc 0:1mmc 0:2debiannvme 0:1ubuntunvme 0:2usb 0:2
If I understand your patch correctly, menus are initially sorted out in the order of * user-defined bootmenu_xxx variables * removable bootable media * user-defined UEFI boot options
The example above looks odd.
That said, it would be worth mentioning that users can changes the order among UEFI-related menus. (Right?)
In addition, please describe the default action if users do not select anything.
-Takahiro Akashi
+Configuration +-------------
The "bootmenu" command is enabled by::
CONFIG_CMD_BOOTMENU=y@@ -88,3 +127,19 @@ To run the bootmenu at startup add these additional settings:: CONFIG_AUTOBOOT_KEYED=y CONFIG_BOOTDELAY=30 CONFIG_AUTOBOOT_MENU_SHOW=y
+UEFI boot variable enumeration is enabled by::
- CONFIG_AUTOBOOT_MENU_SHOW=y
+To improve the product security, entering U-Boot console from bootmenu +can be disabled by::
- CONFIG_CMD_BOOTMENU_ENTER_UBOOT_CONSOLE=n
+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"
-- 2.17.1