Internal Boot mode of Imx6

[prathamrahate]

I have custom board with imx6qp with similar configuration as of imx6q sabre sd. It is currently set to boot mode 10 i.e. internal boot and reads boot configuration from GPIOs. I am setting boot switches to boot from SD card, but board does not boot from sd card.

So through JTAG, i tried to read PLL registers. After reading registers, it looks like PLLs have not been locked or enabled. So is it that when in internal boot mode clocks/PLLs will be disabled ???

I have imx6q sabresd board also, it is also in internal boot mode. But if i read PLL registers , i see PLLs are being locked. So who is enabling the PLLs for sabre sd board??

[jan_spurek]

Hello Pratham,

do you have BT_FUSE_SEL set to 0? If not, then even in internal boot, the boot configuration is read only from eFuses, not from GPIOs.

Best regards,

Jan

[prathamrahate]

Hi Jan,

currently BT_FUSE_SEL = 0, so it is reading boot configuration from GPIOs.

Here are the SBMR1 and  SBMR2 values

SBMR1= 0xf7005040

SBMR2=0x12000001

Thanks,

Prathamesh

[jan_spurek]

SMBR2 looks fine - the same as for the Sabre SD board. However SBMR1 may be configured incorrectly. The value for the Sabre SD board is 0x1040 - BOOT_CFG4 is configured differently (mostly regarding the recovery boot device). Some of the settings are board specific - please check if there are no issues. I think that the probable cause is that Infinite loop is activated. If your board is based on Sabre SD and you didn't make any changes in this area, the same register value should work.

[prathamrahate]

Hi Jan,

Will BOOT_CFG4 affect the clocks ??

observation :

if boot mode is 00 i.e boot from fuses the clocks are coming up as it is falling back to serial downloader mode.

if boot mode is 10 i.e. internal boot mode clocks are not getting configured, also PLLs are not getting locked.

when I halt through JTAG in internal boot mode, PC is

target halted in ARM state due to debug-request, current mode: Supervisor
cpsr: 0x600001d3 pc: 0x0000fe78

So my question is why clocks are not coming up or PLLs are not geeting locked by boot ROM code in internal boot mode???

Will the boot ROM code initialise clocks ??

Thanks,

Prathamesh