Bruning bootloader on soc

Hi Everyone,

I have designed a custom board using Qualcomm 410e.
I’m facing some issues with the bootloader. Please help me out.
These are my questions:

  1. How to burn the Primary bootloader into the SOC.
  2. How to burn Secondary bootloader into EMMC.
    I have added a JTAG connector but I can’t find the steps for the primary and secondary bootloader process.
    Hoping to hear from you soon.
    Thanks in advance.

Anyhelp is appreciate, also let me know if Im wrong about anything in the process

It sounds like you just want to do a board recovery:

@danielt Thank you for the response, I think I didn’t elaborate on the problem enough my bad.

Actually I have fabricated board based on soc and it came to my knowledge afterwards that this soc apparently doesnt come with any type of code (pbl) on it.

Solution that you gave does cover half of my problem regarding the bootloader process but it starts with assuming that soc has pbl in it. How do I go about burning Pbl on soc? or Do I have some kind of misunderstanding about this process ?
Thank you again for the response and any help is appreciated.

The “apparently” in this sentence unerves me slightly. How did this become apparent and where does that information come from?

I have never heard anything that suggested that EDL mode requires a 410E to be pre-programmed (althought admittedly I’ve only ever had a DB410C so I have never really thought about it much).

The PBL is the primary boot loader, e.g. the SoC ROM code. So it is not possible to flash the PBL since it’s builtin in the SoC itself. The discussion is confusing.

Just expanding on what Nico said. The PBL is built into the ASIC, it is in ROM. It cannot be changed, it cannot be removed, it ALWAYS starts first when the chip comes out of reset. The PBL reads the boot mode pins (the DIP switch on the 410c) to determine the next steps in the boot process.

Your carrier board needs to be able to set the boot mode pins that the PBL reads. If the pins are set correctly the board will boot from eMMC, SDIO, or USB. you probably want eMMC for your production code, but to initially load code into the eMMC, you will need to boot from SDIO and use the SDCard recovery method, or boot from USB and use the edl recovery method to load the operating code into the eMMC.

Hope this helps.