avionic design with actual uboot and tooling
submodule of avionic design uboot bootloader and with included tools to get you started , read readme.md and readme-tk1-loader.md
This commit is contained in:
47
u-boot/doc/SPI/README.ti_qspi_flash
Normal file
47
u-boot/doc/SPI/README.ti_qspi_flash
Normal file
@@ -0,0 +1,47 @@
|
||||
QSPI U-Boot support
|
||||
------------------
|
||||
|
||||
Host processor is connected to serial flash device via qpsi
|
||||
interface. QSPI is a kind of spi module that allows single,
|
||||
dual and quad read access to external spi devices. The module
|
||||
has a memory mapped interface which provide direct interface
|
||||
for accessing data form external spi devices.
|
||||
|
||||
The one QSPI in the device is primarily intended for fast booting
|
||||
from Quad SPI flash devices.
|
||||
|
||||
Usecase
|
||||
-------
|
||||
|
||||
MLO/u-boot.img will be flashed from SD/MMC to the flash device
|
||||
using serial flash erase and write commands. Then, switch settings
|
||||
will be changed to qspi boot. Then, the ROM code will read MLO
|
||||
from the predefined location in the flash, where it was flashed and
|
||||
execute it after storing it in SDRAM. Then, the MLO will read
|
||||
u-boot.img from flash and execute it from SDRAM.
|
||||
|
||||
SPI mode
|
||||
-------
|
||||
SPI mode uses mtd spi framework for transfer and reception of data.
|
||||
Can be used in:
|
||||
1. Normal mode: use single pin for transfers
|
||||
2. Dual Mode: use two pins for transfers.
|
||||
3. Quad mode: use four pin for transfer
|
||||
|
||||
Memory mapped read mode
|
||||
-----------------------
|
||||
In this, SPI controller is configured using configuration port and then
|
||||
controller is switched to memory mapped port for data read.
|
||||
|
||||
Driver
|
||||
------
|
||||
drivers/qspi/ti_qspi.c
|
||||
- Newly created file which is responsible for configuring the
|
||||
qspi controller and also for providing the low level api which
|
||||
is responsible for transferring the datas from host controller
|
||||
to flash device and vice versa.
|
||||
|
||||
Testing
|
||||
-------
|
||||
A seperated file named README.dra_qspi_test has been created which gives all the
|
||||
details about the commands required to test qspi at U-Boot level.
|
||||
Reference in New Issue
Block a user