i.MX ProcessorsのトピックuBoot Hardware Awareness

uBoot Hardware Awareness

danielbujak — Tue, 11 Jul 2017 19:03:37 GMT

I'm trying to understand how uBoot knows where to find the necessary hardware and peripherals on the IMX6. For example, when I build the default image uBoot outputs over UART1, but is it possible to have default output on UART2, 3,.. etc. Is there something similar to the DTB that uBoot uses to know what hardware it has available?

Re: uBoot Hardware Awareness

igorpadykov — Tue, 11 Jul 2017 23:34:49 GMT

Hi danielbujak

there is no dtb in uboot, typically some modifications can be set in

uboot/include/configs/board_name.h file. Other hardware changes are

manually entered in code, please also look at attached Porting Guide.

Best regards
igor
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Re: uBoot Hardware Awareness

danielbujak — Wed, 12 Jul 2017 13:31:02 GMT

I found the changes required for the UART:

mx6ul_14x14_evk.h:

#define CONFIG_MXC_UART_BASE UART2_BASE

and

mx6ul_14x14_evk.c:

static iomux_v3_cfg_t const uart2_pads[] = {
MX6_PAD_NAND_DATA04__UART2_DCE_TX | MUX_PAD_CTRL(UART_PAD_CTRL),
MX6_PAD_NAND_DATA05__UART2_DCE_RX | MUX_PAD_CTRL(UART_PAD_CTRL),
};