Linux/AM5728: Code walk through for DDR3 configuration.

Tool/software: Linux

Hello,

I have started working on DDR configuration for our new custom board based on AM5728 Sotara processor, we have taken Am57xx EVM as starting reference and using "PROCESSOR-SDK-LINUX-AM57X  02_00_02_11" .

Before working on our custom design i want to explore the configuration and flow of SDRAM init , i am referring one old post which mention the details what are the changes we need for U-boot code. 

https://e2e.ti.com/support/arm/sitara_arm/f/791/t/464238

My doubt is, In void sdram_init(void) function code is return because "omap_hw_init_context() == OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL" , how can i change this i didn't understood the Configuration head concept.

As I would like to exlopre the DDR configuration with Existing EVM how i can go ahead, please provide me the pointer . how other configuration in take place like MMU configuration and AC timing setting.

Please find the below code snippet:

/*
 * SDRAM initialization:
 * SDRAM initialization has two parts:
 * 1. Configuring the SDRAM device
 * 2. Update the AC timings related parameters in the EMIF module
 * (1) should be done only once and should not be done while we are
 * running from SDRAM.
 * (2) can and should be done more than once if OPP changes.
 * Particularly, this may be needed when we boot without SPL and
 * and using Configuration Header(CH). ROM code supports only at 50% OPP
 * at boot (low power boot). So u-boot has to switch to OPP100 and update
 * the frequency. So,
 * Doing (1) and (2) makes sense - first time initialization
 * Doing (2) and not (1) makes sense - OPP change (when using CH)
 * Doing (1) and not (2) doen't make sense
 * See do_sdram_init() for the details
 */
void sdram_init(void)
{
        u32 in_sdram, size_prog, size_detect;
        struct emif_reg_struct *emif = (struct emif_reg_struct *)EMIF1_BASE;
        u32 sdram_type = emif_sdram_type(emif->emif_sdram_config);

        debug(">>sdram_init()\n");
        printf(">>sdram_init()\n");

        if (omap_hw_init_context() == OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL)
        {
        printf("+++++++++++>>sdram_init() Omap_hw_init = %d \n ",omap_hw_init_context());
        return;
        }

        in_sdram = running_from_sdram();
        debug("in_sdram = %d\n", in_sdram);

Thanks

Mishra80