RT-UFL is a universal flashloader, one .FLM file for all i.MXRT chips, it should be integrated into Segger driver (or Keil MDK), then you can download and debug MCUXpresso SDK XIP project by J-Link.
The main features of RT-UniversalFlashloader：
- Can run on all i.MXRT chips.
- Can support any serial NOR Flash that can be used as i.MXRT boot device .
- Can erase and program Flash connected to ROM specified pinmux.
- Can auto-detect serial NOR Flash type (QuadSPI, Octal-SPI, Hyperbus).
- Can auto-detect SFDP version of Flash.
- Can support Flash without SFDP.
- Can auto-detect default QE bit status of QuadSPI Flash.
- Can output necessary information of Flash for boot header.
The block diagram of RT-UniversalFlashloader：
RT-UniversalFlashloader contains three layers:
- [API Layer]: API is defined by Tool (Segger, Keil MDK).
- [Adapter Layer]: The key layer to support different i.MXRT chips and NOR Flash chips.
- [Driver Layer]: The low-level FlexSPI NOR driver.
To develop RT-UniversalFlashloader, we should be aware of below notes:
- Always use Cortex-M0 instruction set to build final .FLM file.
- There is no device ID in i.MXRT, we can take use of ROM content to find part number.
- Most i.MXRT chips contain ROM API, we can use ROM API as low-level NOR driver.
- Flash auto-probe feature is added in i.MXRT1060 BootROM, we can refer to this feature to develop key flash_auto_probe() function.
- soft reset command should be issued to reset Flash after every failed attempt in flash_auto_probe()