efi_loader: return binary from efi_dp_from_lo()

For finding distro supplied device-trees we need to know from which device
we are booting. This can be identified via the device-path of the binary.

Up to now efi_dp_from_lo() only could return the initrd or fdt device-path.
Allow returning the binary device-path, too.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
This commit is contained in:
Heinrich Schuchardt 2024-04-26 16:13:19 +02:00
parent c946385950
commit b34528ebad

View file

@ -1133,17 +1133,18 @@ ssize_t efi_dp_check_length(const struct efi_device_path *dp,
} }
/** /**
* efi_dp_from_lo() - Get the instance of a VenMedia node in a * efi_dp_from_lo() - get device-path from load option
* multi-instance device path that matches
* a specific GUID. This kind of device paths
* is found in Boot#### options describing an
* initrd location
* *
* @lo: EFI_LOAD_OPTION containing a valid device path * The load options in U-Boot may contain multiple concatenated device-paths.
* @guid: guid to search for * The first device-path indicates the EFI binary to execute. Subsequent
* device-paths start with a VenMedia node where the GUID identifies the
* function (initrd or fdt).
*
* @lo: EFI load option containing a valid device path
* @guid: GUID identifying device-path or NULL for the EFI binary
* *
* Return: * Return:
* device path including the VenMedia node or NULL. * device path excluding the matched VenMedia node or NULL.
* Caller must free the returned value. * Caller must free the returned value.
*/ */
struct struct
@ -1154,6 +1155,9 @@ efi_device_path *efi_dp_from_lo(struct efi_load_option *lo,
struct efi_device_path_vendor *vendor; struct efi_device_path_vendor *vendor;
int lo_len = lo->file_path_length; int lo_len = lo->file_path_length;
if (!guid)
return efi_dp_dup(fp);
for (; lo_len >= sizeof(struct efi_device_path); for (; lo_len >= sizeof(struct efi_device_path);
lo_len -= fp->length, fp = (void *)fp + fp->length) { lo_len -= fp->length, fp = (void *)fp + fp->length) {
if (lo_len < 0 || efi_dp_check_length(fp, lo_len) < 0) if (lo_len < 0 || efi_dp_check_length(fp, lo_len) < 0)