Hi Hector, Hector Palacios wrote:
> Apparently the problem was due to my platform suffering a hardware > specific VDDD brownout during the initialization. > > Just in case it helps anybody, the reason why I was not able to see > anything on the DUART port during SPL initialization, despite having > enabled CONFIG_SPL_SERIAL_SUPPORT and having serial_puts() on the SPL > code, was that my platform uses alternate pins for the DUART than the > default used by the BOOT ROM and the EVK, so apart from configuring the > correct IOMUX, I needed to unconfigure the pins used by BOOT ROM for the > DUART (on board/<vendor>/iomux.c): > > @@ -33,8 +33,12 @@ > > const iomux_cfg_t iomux_setup[] = { > /* DUART */ > - MX28_PAD_PWM0__DUART_RX, > - MX28_PAD_PWM1__DUART_TX, > + /* Unconfigure BOOT ROM default DUART */ > + MX28_PAD_PWM0__GPIO_3_16, > + MX28_PAD_PWM1__GPIO_3_17, > + /* Configure DUART on alternate pins */ > + MX28_PAD_I2C0_SCL__DUART_RX, > + MX28_PAD_I2C0_SDA__DUART_TX, > > /* MMC0 */ > MX28_PAD_SSP0_DATA0__SSP0_D0 | MUX_CONFIG_SSP0, > @@ -159,9 +163,6 @@ const iomux_cfg_t iomux_setup[] = { > MX28_PAD_SSP2_MISO__SSP2_D0 | MUX_CONFIG_SSP2, > MX28_PAD_SSP2_SS0__SSP2_D3 | > (MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP), > - /* I2C */ > - MX28_PAD_I2C0_SCL__I2C0_SCL, > - MX28_PAD_I2C0_SDA__I2C0_SDA, > }; > > #define HW_DRAM_CTL29 (0x74 >> 2) Thanks for sharing your solution. It seems that the other mx28 boards we currently have all use MX28_PAD_PWM0__DUART_RX / MX28_PAD_PWM1__DUART_TX for DUART and then we never faced this issue. It would be great if you can submit a patch for adding support to your board in U-boot. Regards, Fabio Estevam _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot