[U-Boot] Das U-Boot 'bootaux' command breaks USB communication from and to main CPU

Dear sir, madam,
Our product uses the i.MX 6SoloX SOC with a Cortex A9 and M4, U-Boot runs on the A9 and boots Linux. But before booting Linux it executes the 'bootaux 0x7F800' command to boot the M4. However, Linux is unable to initialize the USB when this command is executed.
This problem persist when:
- there is no binary loaded on the M4 (and thus it is not code on the M4 that's breaking the USB);
- the bootaux command is called with a different address (and thus not it is not booting the M4 that's breaking the USB).
The problem is solved when the bootaux command is removed from the boot sequence. However, this way only the A9 boots and we would like to boot the M4 as well.
Our U-Boot version is: 2015.04-master+gc75e0f3
We are currently looking into different ways to boot the M4 from Linux instead of U-Boot, however we were hoping you could help us too.
Hope te hear from you soon,
Lucan de Groot Embedded Software Engineer + 31 (0)6 409 170 21 lucan.degroot@quby.com | www.quby.comhttp://www.quby.com/ | subscribe to our newsletterhttps://mailchi.mp/66cc8a1f175c/subscribe
Quby is hiring! Join our ambitious team to outsmart energy - https://www.quby.com/careers

Hi Lucan,
Dear sir, madam,
Our product uses the i.MX 6SoloX SOC with a Cortex A9 and M4, U-Boot runs on the A9 and boots Linux. But before booting Linux it executes the 'bootaux 0x7F800' command to boot the M4. However, Linux is unable to initialize the USB when this command is executed.
This problem persist when:
- there is no binary loaded on the M4 (and thus it is not code on the
M4 that's breaking the USB);
- the bootaux command is called with a different address (and thus
not it is not booting the M4 that's breaking the USB).
The problem is solved when the bootaux command is removed from the boot sequence.
This is very strange. I thought that bootaux loads the binary to memory and points Cortex-M's PC to it.
However, this way only the A9 boots and we would like to boot the M4 as well.
Our U-Boot version is: 2015.04-master+gc75e0f3
Would there be any chance to check newest master ?
We are currently looking into different ways to boot the M4 from Linux instead of U-Boot, however we were hoping you could help us too.
I do have a HW with NXP's Vybrid SoC (Cortex-A5 and M3). However, my used case doesn't require loading M3 firmware.
Hope te hear from you soon,
Lucan de Groot Embedded Software Engineer
- 31 (0)6 409 170 21
lucan.degroot@quby.com | www.quby.comhttp://www.quby.com/ | subscribe to our newsletterhttps://mailchi.mp/66cc8a1f175c/subscribe
Quby is hiring! Join our ambitious team to outsmart energy - https://www.quby.com/careers
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Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
participants (2)
-
Lucan de Groot
-
Lukasz Majewski