Instead of discovering the ID of the device and call two different
functions for a block device or a partition, we can rewrite
efi_disk_remove() and handle the minor differences between the two
variants internally.  As a results we can simplify efi_disk_remove()
a lot and get rid of the extra efi_disk_delete_raw/blk calls.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

If a handle is not found, return 0 to let the device be removed.

Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

part_get_info() may return an error code. Check it.
Update function description of dp_part_node().

Addresses-Coverity-ID: 184067 ("Unchecked return value")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

* When called from efi_dp_from_name() we miss to append the filename
  for non-block devices.
* expand_media_path() could be simplified by using efi_dp_from_file to
  prepend the device path of the boot device.

This can be avoided by passing a device path to efi_dp_from_file() instead
of a block device descriptor and a partition number.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Don't do the same check and assignment in multiple places.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Use EFI_OUT_OF_RESOURCES if the device path cannot be constructed.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

* Improve variable name usage: Use pos instead of buf to indicate the
  current position in a buffer.
* Avoid double assignment in a single code line.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

efi_dp_from_name() has duplicate code to replace slash by backslash.
path_to_uefi() called by efi_dp_from_file() already does this.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

According to our coding style guide #ifdef should be avoided.
Use IS_ENABLED() instead.

Sort string comparisons alphabetically.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Executing an EFI binary fails for files loaded via semihosting.

Construct a dummy device path for EFI binaries loaded via semihosting.

A future complete solution may include the creation of a handle with a
simple file system protocol.

Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Helloworld.efi should print the file path even if the boot device is
not set.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>