efi_loader: description EFI_LOAD_FILE2_PROTOCOL

U-Boot offers a EFI_LOAD_FILE2_PROTOCOL which the Linux EFI stub can use to
load an initial RAM disk. Update the function comments of the
implementation.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
This commit is contained in:
Heinrich Schuchardt 2020-10-03 12:44:31 +02:00
parent b24550accd
commit 5cd28e1760

View File

@ -47,9 +47,9 @@ static const struct efi_initrd_dp dp = {
/**
* get_file_size() - retrieve the size of initramfs, set efi status on error
*
* @dev: device to read from. i.e "mmc"
* @part: device partition. i.e "0:1"
* @file: name fo file
* @dev: device to read from, e.g. "mmc"
* @part: device partition, e.g. "0:1"
* @file: name of file
* @status: EFI exit code in case of failure
*
* Return: size of file
@ -78,15 +78,16 @@ out:
}
/**
* load_file2() - get information about random number generation
* efi_load_file2initrd() - load initial RAM disk
*
* This function implements the LoadFile service of the EFI_LOAD_FILE2_PROTOCOL
* in order to load an initial RAM disk requested by the Linux kernel stub.
*
* This function implement the LoadFile2() service in order to load an initram
* disk requested by the Linux kernel stub.
* See the UEFI spec for details.
*
* @this: loadfile2 protocol instance
* @file_path: relative path of the file. "" in this case
* @boot_policy: must be false for Loadfile2
* @this: EFI_LOAD_FILE2_PROTOCOL instance
* @file_path: media device path of the file, "" in this case
* @boot_policy: must be false
* @buffer_size: size of allocated buffer
* @buffer: buffer to load the file
*
@ -128,7 +129,13 @@ efi_load_file2_initrd(struct efi_load_file_protocol *this,
goto out;
}
/* expect something like 'mmc 0:1 initrd.cpio.gz' */
/*
* expect a string with three space separated parts:
*
* * a block device type, e.g. "mmc"
* * a device and partition identifier, e.g. "0:1"
* * a file path on the block device, e.g. "/boot/initrd.cpio.gz"
*/
dev = strsep(&s, " ");
if (!dev)
goto out;
@ -168,23 +175,20 @@ out:
}
/**
* efi_initrd_register() - Register a handle and loadfile2 protocol
* efi_initrd_register() - create handle for loading initial RAM disk
*
* This function creates a new handle and installs a linux specific GUID
* to handle initram disk loading during boot.
* See the UEFI spec for details.
* This function creates a new handle and installs a Linux specific vendor
* device path and an EFI_LOAD_FILE_2_PROTOCOL. Linux uses the device path
* to identify the handle and then calls the LoadFile service of the
* EFI_LOAD_FILE_2_PROTOCOL to read the initial RAM disk.
*
* Return: status code
* Return: status code
*/
efi_status_t efi_initrd_register(void)
{
efi_handle_t efi_initrd_handle = NULL;
efi_status_t ret;
/*
* Set up the handle with the EFI_LOAD_FILE2_PROTOCOL which Linux may
* use to load the initial ramdisk.
*/
ret = EFI_CALL(efi_install_multiple_protocol_interfaces
(&efi_initrd_handle,
/* initramfs */