Control GPIO from boot loader (am3517)

I need to control an GPIO from the boot loader.

I modify the function board_init() in

u-boot-2009.11-psp03.00.01.06.sdk/board/ti/var-am35xx/var-am35xx.c

int board_init(void)
{
        unsigned int Teo1;
        DECLARE_GLOBAL_DATA_PTR;

    gpmc_init(); /* in SRAM or SDRAM, finish GPMC */
    /* board id for Linux */
    gd->bd->bi_arch_number = MACH_TYPE_OMAP3517EVM;
    /* boot param addr */
    gd->bd->bi_boot_params = (OMAP34XX_SDRC_CS0 + 0x100);

        Teo1 = (*(volatile unsigned int *)(OMAP34XX_GPIO5_BASE + OMAP24XX_GPIO_OE));//set direction
        Teo1 = Teo1 | 0b1000;   //4 I/O (gpio_131) is an input
        (*(volatile unsigned int   *)(OMAP34XX_GPIO5_BASE + OMAP24XX_GPIO_OE)) = Teo1;
        while (1)
        {
                unsigned int nTeo2 = (*(volatile unsigned int   *)(OMAP34XX_GPIO5_BASE + OMAP24XX_GPIO_DATAOUT));
                unsigned int nTeo3 = (*(volatile unsigned int   *)(OMAP34XX_GPIO5_BASE + OMAP24XX_GPIO_DATAIN));
                printf("nTeo2 %d\n",nTeo2);
                printf("nTeo3 %d\n",nTeo3);
        }
        return 0;

}

The outuput string doesn't change even if I change the the input.
Where Is the error?

Is there another modality?

Thanks

Teo