Tool/software:
Hi,I am currently working on a project using the TI AM335x EPC platform and have encountered an issue with booting from eMMC.
Below are the details of the current setup and the challenges I am facing.
■ Development Environment:
・Platform: TI AM3352
・Software Version: Yocto 2.4
・Boot Media: SD card, eMMC, SPI Flash (SPI0)
■ Problem Background:
I have built a new Yocto 2.4 image and successfully generated the corresponding MLO file.
When booting from the SD card, the new MLO file is loaded correctly, and the boot process works as expected.
However, when booting from eMMC, the device still loads the older MLO file that was originally pre-installed.
After investigation, I discovered that due to the hardware configuration, booting directly from eMMC is not possible. The MLO file must be copied to SPI Flash (SPI0) for the system to boot. The hardware setup involves the boot sequence SPI0 -> MMC0.
■ Challenges:
1.Is the MLO file generated for the SD card compatible with SPI Flash (SPI0) as is, or does it require specific modifications or settings?
2.What is the correct method to flash the MLO file to SPI Flash (SPI0)?（What is the correct offset or address for storing the MLO file in SPI Flash?）
3.To boot the root file system on eMMC from SPI0, I assume SPI0 must also include u-boot.bin, U-Boot parameters, DTB, and the Linux kernel.
How can these components be packaged into a single image, and how can this image be flashed to SPI0?
4.Alternatively, if it is possible to bypass SPI0 and boot directly from MMC0 (loading MLO, u-boot.bin, and the kernel from eMMC) without changing the hardware configuration, I would like to know how to achieve that.
■ Steps Already Taken:
・Built and verified the MLO file using Yocto.
・Successfully tested the MLO file on SD card boot.
■ Request: I would appreciate it if you could provide the following information:
1.Can the MLO file generated for the SD card be flashed directly to SPI Flash?
2.Detailed steps and tools for flashing the MLO file to SPI Flash, especially regarding the required offsets or configurations.
3.How to package and flash additional components (u-boot.bin, DTB, kernel, etc.) to SPI0 for booting eMMC root file system.
4.If possible, a method to skip SPI0 and boot directly from MMC0 without modifying the hardware.
Thank you for your support and guidance!
