b634477481
This patch extends the generated grub.cfg so that it can use the external environment block when the variable env_block is defined. During boot, if env_block is set, grub.cfg builds a device path for it, exports the variable, and then loads its contents in addition to the normal grubenv file. When GRUB writes variables such as next_entry or saved_entry, the save commands are changed to write into env_block if it is set, and to fall back to the grubenv file otherwise. In this way the external environment block is used automatically, and existing commands like savedefault or save_env do not need to change. Signed-off-by: Michael Chang <mchang@suse.com> Reviewed-by: Neal Gompa <ngompa13@gmail.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
All executable files in this directory are processed in shell expansion order. 00_*: Reserved for 00_header. 10_*: Native boot entries. 20_*: Third party apps (e.g. memtest86+). The number namespace in-between is configurable by system installer and/or administrator. For example, you can add an entry to boot another OS as 01_otheros, 11_otheros, etc, depending on the position you want it to occupy in the menu; and then adjust the default setting via /etc/default/grub.