How to switch the legs of the UART in u-boot, into which the boot log is displayed?

Question

linux

Good afternoon, we are
developing a custom board based on a TI SITARA processor, namely AM5728.
Their evaluation was bought to play around. They played enough with it, and when developing a custom board, the circuit engineer was told: "In order not to rewrite the UART firewood, connect it exactly the same as on the evaluation."
On evaluation, UART and Linux log output is implemented via UART3. But the legs of the C28 and D27 processor are used there.
Our frame hung UART3 on the legs of AB3 and Y1.
Haven't worked with fresh linux based on dts yet. Therefore, they shook it up thoroughly.
We dug up U-BOOT to such an interesting moment:
in the file arch/arm/dts/am57xx-beagle-x15.dts we found a choice of UART3 legs:

uart3_pins_default: uart3_pins_default {
    pinctrl-single,pins = <
      0x3f8 (PIN_INPUT_SLEW | MUX_MODE2) /* uart2_ctsn.uart3_rxd */
      0x3fc (PIN_INPUT_SLEW | MUX_MODE1) /* uart2_rtsn.uart3_rxd */
    >;
  };

We turned off the default legs, turned on the ones we needed:

uart3_pins_default: uart3_pins_default {
    pinctrl-single,pins = <
      0x24c (PIN_OUTPUT_PULLUP | MUX_MODE0) /* uart3_txd.uart3_txd */
      0x34c (PIN_INPUT_PULLUP | MUX_MODE4) /* mcasp_axr0.uart3_rxd */
      0x3f8 (PIN_INPUT_SLEW | MUX_MODE15) /* uart2_ctsn.uart3_rxd */
      0x3fc (PIN_INPUT_SLEW | MUX_MODE15) /* uart2_rtsn.uart3_txd */
    >;
  };

But surprisingly, it didn't change anything.
this uboot on the evaluation still outputs the log to the console, but there is no log on our custom board.
This file is definitely used by the system, because. if you change the uart, for example, from the third to the second, then the log disappears on the evaluation.
Of course, I don’t even hope to hear what specific bits where to write so that our custom uart comes to life.
But I will be very glad to any hints, who have already worked with a fresh ubut, why the legs do not switch.
I will also be glad to any fresh manuals for assembling custom boots.
ps
Please do not offer to kick the circuitry =)
ZZY.
Of course, they wrote to the ti forum, but they apparently don’t know themselves, because. they only offer to read the manuals, which have already been studied up and down.
z.z.z.y
without a working output of the U-BOOT log, there is nowhere further, because. without it, we cannot load Linux and the file system via y-modem.
Thank you!

Answer 1

It turned out that we switched legs correctly.
But in the configuration of this evaluation, there is a check for compliance with the fit of the image
CONFIG_SPL_LOAD_FIT = y,
respectively, the check was disabled and u-boot booted.
Well, the same thing started with Linux))