Improve the documentation of the bli module and explain in more detail what
it does. Make clear that GPT formatted drives are expected and other
partition formats are ignored. Also reorder and reword this section a bit.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The bli module has a "hidden" dependency on the part_gpt module, which
is not picked up automatically by the build system. One purpose of the
bli module is to communicate the GPT UUID of the partition GRUB was
launched from to Linux user-space (systemd-gpt-auto-generator).
Without the part_gpt module, bli is not able to obtain the UUID. Since
bli does its work in the module initialization function, the order in
which the modules are loaded is also important: part_gpt needs to be
loaded before the bli module.
To solve this, track this dependency explicitly.
Note that the Boot Loader Interface specification, which bli aims to
implement, requires GPT formatted drives. The bli module ignores all
other partition formats.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The build system deduces inter-module dependencies from the symbols
required and exported by the modules. This works well, except for some
rare cases where the dependency is indirect or hidden. A module might
not make use of any function of some other module, but still expect its
functionality to be available to GRUB.
To solve this, introduce a new file, currently empty, called extra_deps.lst
to track these cases manually. This file gets processed in the same way
as the automatically generated syminfo.lst, making it possible to inject
data into the dependency resolver.
Since *.lst files are set to be ignored by git, add an exception for
extra_deps.lst.
Additionally, introduce a new keyword for the syminfo.lst syntax:
"depends" allows specifying a module dependency directly:
depends <module> <depdendency>...
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add a new configuration drop-in file that loads the bli module and runs
the command if booting on the EFI platform.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add a new module named bli. It implements a small but quite useful part
of the Boot Loader Interface [0]. This interface uses EFI variables for
communication between the boot loader and the operating system.
When loaded, this module sets two EFI variables under the vendor GUID
4a67b082-0a4c-41cf-b6c7-440b29bb8c4f:
- LoaderInfo: contains GRUB + <version number>.
This allows the running operating system to identify the boot loader
used during boot.
- LoaderDevicePartUUID: contains the partition UUID of the EFI System
Partition (ESP). This is used by systemd-gpt-auto-generator [1] to
find the root partitions (and others too), via partition type IDs [2].
This module is available on EFI platforms only. The bli module relies on
the part_gpt module which has to be loaded beforehand to make the GPT
partitions discoverable.
Update the documentation, add a new chapter "Modules" and describe the
bli module there.
[0] https://systemd.io/BOOT_LOADER_INTERFACE/
[1] https://www.freedesktop.org/software/systemd/man/systemd-gpt-auto-generator.html
[2] https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add checks for NULL pointers to grub_device_close() and
grub_disk_close() to make these functions more robust.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reword some section headings, remove "The List of" from titles. While
grammatically correct, this phrase can be omitted to increase
readability, especially in the table of contents.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add a function that sets an EFI variable to a string value.
The string is converted from UTF-8 to UTF-16.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Create a new function for UTF-8 to UTF-16 conversion called
grub_utf8_to_utf16_alloc() in the grub-code/kern/misc.c and replace
charset conversion code used in some places in the EFI code. It is
modeled after the grub_utf8_to_ucs4_alloc() like functions in
include/grub/charset.h. It can't live in include/grub/charset.h,
because it needs to be reachable from the kern/efi code.
Add a check for integer overflow and remove redundant NUL-termination.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Use the new printf format specifier %pG.
Fixes the text representation of GUIDs in the output of the lsefisystab
command (missing 4th dash).
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Extend the printf format specifier for pointers (%p) to accept a suffix
specifier G to print GUIDs: %pG can be used to print grub_guid structs.
This does not interfere with the -Wformat checking of gcc. Note that
the data type is not checked though (%p accepts void *).
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
There are 3 implementations of a GUID in GRUB. Replace them with
a common one, placed in types.h.
It uses the "packed" flavor of the GUID structs, the alignment attribute
is dropped, since it is not required.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Add a function to the EFI module that allows setting EFI variables
with specific attributes.
This is useful for marking variables as volatile, for example.
Signed-off-by: Oliver Steffen <osteffen@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Oliver Steffen