mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-25 04:23:46 +00:00
45029758be
Provide information about - overview of file system firmware loader driver model - describe storage device and partition in device tree source - describe fie system firmware loader API Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com> Reviewed-by: Simon Glass <sjg@chromium.org>
133 lines
4.3 KiB
Text
133 lines
4.3 KiB
Text
# Copyright (C) 2018 Intel Corporation <www.intel.com>
|
|
#
|
|
# SPDX-License-Identifier: GPL-2.0
|
|
|
|
Introduction
|
|
============
|
|
|
|
This is file system firmware loader for U-Boot framework, which has very close
|
|
to some Linux Firmware API. For the details of Linux Firmware API, you can refer
|
|
to https://01.org/linuxgraphics/gfx-docs/drm/driver-api/firmware/index.html.
|
|
|
|
File system firmware loader can be used to load whatever(firmware, image,
|
|
and binary) from the storage device in file system format into target location
|
|
such as memory, then consumer driver such as FPGA driver can program FPGA image
|
|
from the target location into FPGA.
|
|
|
|
To enable firmware loader, CONFIG_FS_LOADER need to be set at
|
|
<board_name>_defconfig such as "CONFIG_FS_LOADER=y".
|
|
|
|
Firmware Loader API core features
|
|
---------------------------------
|
|
|
|
Firmware storage device described in device tree source
|
|
-------------------------------------------------------
|
|
For passing data like storage device phandle and partition where the
|
|
firmware loading from to the firmware loader driver, those data could be
|
|
defined in fs-loader node as shown in below:
|
|
|
|
Example for block device:
|
|
fs_loader0: fs-loader@0 {
|
|
u-boot,dm-pre-reloc;
|
|
compatible = "u-boot,fs-loader";
|
|
phandlepart = <&mmc 1>;
|
|
};
|
|
|
|
<&mmc 1> means block storage device pointer and its partition.
|
|
|
|
Above example is a description for block storage, but for UBI storage
|
|
device, it can be described in FDT as shown in below:
|
|
|
|
Example for ubi:
|
|
fs_loader1: fs-loader@1 {
|
|
u-boot,dm-pre-reloc;
|
|
compatible = "u-boot,fs-loader";
|
|
mtdpart = "UBI",
|
|
ubivol = "ubi0";
|
|
};
|
|
|
|
Then, firmware_loader property would be set with the path of fs_loader
|
|
node under /chosen node such as:
|
|
/{
|
|
chosen {
|
|
firmware_loader = &fs_loader0;
|
|
};
|
|
};
|
|
|
|
However, this driver is also designed to support U-boot environment
|
|
variables, so all these data from FDT can be overwritten
|
|
through the U-boot environment variable during run time.
|
|
For examples:
|
|
"storage_interface" - Storage interface, it can be "mmc", "usb", "sata"
|
|
or "ubi".
|
|
"fw_dev_part" - Block device number and its partition, it can be "0:1".
|
|
"fw_ubi_mtdpart" - UBI device mtd partition, it can be "UBI".
|
|
"fw_ubi_volume" - UBI volume, it can be "ubi0".
|
|
|
|
When above environment variables are set, environment values would be
|
|
used instead of data from FDT.
|
|
The benefit of this design allows user to change storage attribute data
|
|
at run time through U-boot console and saving the setting as default
|
|
environment values in the storage for the next power cycle, so no
|
|
compilation is required for both driver and FDT.
|
|
|
|
File system firmware Loader API
|
|
-------------------------------
|
|
|
|
int request_firmware_into_buf(struct device_platdata *plat,
|
|
const char *name,
|
|
void *buf, size_t size, u32 offset,
|
|
struct firmware **firmwarep)
|
|
--------------------------------------------------------------------
|
|
Load firmware into a previously allocated buffer
|
|
|
|
Parameters:
|
|
|
|
1. struct device_platdata *plat
|
|
Platform data such as storage and partition firmware loading from
|
|
|
|
2. const char *name
|
|
name of firmware file
|
|
|
|
3. void *buf
|
|
address of buffer to load firmware into
|
|
|
|
4. size_t size
|
|
size of buffer
|
|
|
|
5. u32 offset
|
|
offset of a file for start reading into buffer
|
|
|
|
6. struct firmware **firmwarep
|
|
pointer to firmware image
|
|
|
|
return:
|
|
size of total read
|
|
-ve when error
|
|
|
|
Description:
|
|
The firmware is loaded directly into the buffer pointed to by buf and
|
|
the @firmwarep data member is pointed at buf
|
|
|
|
Note: Memory would be allocated for firmware image, hence user should
|
|
free() *firmwarep and *firmwarep->priv structs after usage of
|
|
request_firmware_into_buf(), otherwise it will always leak memory
|
|
while subsequent calls of request_firmware_into_buf() with the same
|
|
*firmwarep argument. Those arguments can be free through calling API
|
|
below release_firmware();
|
|
|
|
Example of creating firmware loader instance and calling
|
|
request_firmware_into_buf API:
|
|
if (uclass_get_device(UCLASS_FS_FIRMWARE_LOADER, 0, &dev)) {
|
|
request_firmware_into_buf(dev->plat, filename, buffer_location,
|
|
buffer_size, offset_ofreading, &fw);
|
|
}
|
|
|
|
void release_firmware(struct firmware *firmware)
|
|
------------------------------------------------
|
|
Release the resource associated with a firmware image
|
|
|
|
Parameters:
|
|
|
|
1. struct firmware *firmware
|
|
Firmware resource to release
|