Jumping from application running on internal ram to Boot Rom

[niranjanbc]

below are the functions i perform now on IMx6Solox board.

1. i have U-boot.2016 running which loads simple binary to internal ram. below are the steps performed.

      a. fatload mmc ${mmcdev}:${mmcpart} 0x00907000 simplebinary.bin

      b. dcache off

      c. icache off

      d. go 0x907000

2. now in simple binary fimrware executing out of internal, i do ddr ram test( writing and reading back to memory area)

3. once i finish the ram test, i jump back to boot rom has below.

        void (*bootRom)(void) = 0x000;

        (*bootRom)();

4. now it jumps back and start u-boot fine, but what i observe is i am not control GPIO pins at all.

 i tried all gpio commands gpio set 8,  gpio clear 8.... nothing works.

the same gpio control works fine in u-boot before starting simple binary firmware from internal ram.

i have recycle the power to make it work again.

[niranjanbc]

looks like problem with software get_gpio_value() function

or i need to set the mux mode sion else which will not read gpio back properly.

problem solved 

thanks for your response

[igorpadykov]

Hi niranjanbc

one can attach jtag debugger and try to toggle gpios, to check

if this is not related to hardware. Recycling power board, makes all

board components to be in predefined (reset) state, while uboot may change

their states. Rerunning boot rom from 0 is similar to software reset,  for its issues may

be useful to look at AN5161 Powering an i.MX 6SX-based system p.24, ENGR00338067

https://www.nxp.com/docs/en/application-note/AN5161.pdf 

Best regards
igor
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[niranjanbc]

I can toggle the gpio from debugger, but not through the u-boot