AM3352: Flashing u-boot and Linux to the empty eMMC not using SD card

Adam Kozlowski

Part Number: AM3352
Other Parts Discussed in Thread: SEGGER, DP83822I

Hi,

I have a custom board with AM3352 and eMMC connected.
The board has three interfaces I can use to interact with it:
JTAG - 10pin needle segger
UART (uart0)
Ethernet - RMI in master mode (DP83822i)

Assuming I don't have an SD card socket installed, what are the available options to flash eMMC (mmc1)?
I have everything (U-boot, Linux) prepared and verified using this custom board version with the SD card socket installed.

Can anyone point me in the right direction?
What is the recommended (fast and straightforward) way to flash eMMC in such a configuration without SD card ?
Where can I find relevant information?

Regards
Adam

over 4 years ago

0 Bin Liu over 4 years ago

TI__Guru**** 172951 points

Hi Adam,

You can use Ethernet boot, load U-Boot and Kernel with ramfs from Ethernet, then you can use whatever the Linux utility to flash emmc. The tiny rootfs image in the Processor SDK Linux v6.03 can be used for the ramfs image.

0 Adam Kozlowski over 4 years ago in reply to Bin Liu

Expert 1805 points

Hi Bin,

Bin Liu said:
You can use Ethernet boot

Can I use Ethernet boot, once I have PHY connected using RMII in master mode?

Regards
Adam

0 Bin Liu over 4 years ago in reply to Adam Kozlowski

TI__Guru**** 172951 points

Hi Adam,

I know AM335x supports boot from Ethernet, but I know little about Ethernet itself. I am looping in our Ethernet expert for further support.

0 Adam Kozlowski over 4 years ago in reply to Bin Liu

Expert 1805 points

Hi Bin,

Take a look at the TRM.
Table 26-7. SYSBOOT Configuration Pins.
The SYSBOOT[7:6] bits are for interface choosing.

In 26.1.9.4 EMAC Boot Procedure, we can read:
"
ROM expects an external 50MHz reference clock requirement when using RMII
"
In Table 26-32. Pins Used for EMAC Boot in RMII Mode, there is also rmii1_refclk signal, so AM335x expects PHY to be in the master mode.

According to this information, it seems feasible.

Anyway, please confirm this information with "Ethernet" experts.
I look forward to this confirmation.

Regards
Adam

0 Bin Liu over 4 years ago in reply to Adam Kozlowski

TI__Guru**** 172951 points

Hi Adam,

I haven't heard response yet. But I believe the Ethernet boot function has been validated on AM335x GP EVM.

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AM3352: Flashing u-boot and Linux to the empty eMMC not using SD card