U-Boot SPL not jumping to U-Boot location on RAM on AM335x

Hi Brigols,

Are there any error messages after you load u-boot.img?

Please enable SPL/U-Boot's debug messages. Add the following to <u-boot_dir>/include/configs/am335x_evm.h:

#define DEBUG

Best regards,
Miroslav

Hi Miroslav

  I added the DEBUG and recompile but it becomes very weird, please see below console snapshot; (added some puts() for debug)

Jumping to spl_ymodem_load_image() function

Starting YMODEM Load Image:

CStarting s_init(void) function /arch/arm/cpu/armv7/am335xx folder:

Disbaling Watchdog /arch/arm/cpu/armv7/am335xx folder:

Done Disbaling Watchdog /arch/arm/cpu/armv7/am335xx folder:

Starting uart_soft_reset(void) function /arch/arm/cpu/armv7/am335xx folder

When the SPL reaches spl_ymodem_load_image fucntion it loops back to s_init function and hang at uart_soft_reset function, could this be a linker or compiler issue? We are using gcc-linaro-arm-linux-gnueabihf-4.7-2013.03-20130313_linux cross compiler, we did not use the ti_sdk installer and run ubuntu 14.04 on virtual box.

Brigols,

The reason it jumps to s_init() again is that both SPL and U-Boot start with s_init(). After all, they are both built from almost the same source code. The difference is that the SPL version of s_init() has a few more steps to execute like:

   /*
     * Save the boot parameters passed from romcode.
     * We cannot delay the saving further than this,
     * to prevent overwrites.
     */
#ifdef CONFIG_SPL_BUILD
    save_omap_boot_params();
#endif

and

#elif defined(CONFIG_SPL_BUILD)
    gd = &gdata;
    preloader_console_init();
#endif

Check inside the uart_soft_reset() function for where exactly is it hanging. The problem is most probably related to reading/writing to a register, but I need to know which one, in order to ask our hardware engineer for the possible reason.

Best regards,
Miroslav

Hi Miroslav,

    Thank you for your support, I will look into that function where it hangs and feedback to you asap...

Thanks

Brigols

Hi Miroslav,

   One more thing why did it jump directly to s_init( ) function where it should wait first for the u-boot.img to be loaded?

Thanks

Regards,

Hi Miroslav

        I checked the uart soft_reset_function, put some debug message to see if it execute the function and it stuck at SYSC register, see below.

static void uart_soft_reset(void)
{
	struct uart_sys *uart_base = (struct uart_sys *)DEFAULT_UART_BASE;
	u32 regval;

	debug("Starting uart_soft_reset(void) function /arch/arm/cpu/armv7/am335xx folder:\n");

	regval = readl(&uart_base->uartsyscfg);
	printf("uartsyscfg value is 0x%X\n", regval);
	regval |= UART_RESET;
	debug("Resetting UART module:\n");
	writel(regval, &uart_base->uartsyscfg);
	debug("..........:\n");
	writel(regval, &uart_base->uartsyscfg);
	debug("Reset in progress...:\n");
	while ((readl(&uart_base->uartsyssts) & UART_CLK_RUNNING_MASK) != UART_CLK_RUNNING_MASK);
	debug("Done resetting UART module:\n");

	/* Disable smart idle */
	debug("Disable Smart Idle module:\n");
	regval = readl(&uart_base->uartsyscfg);
	regval |= UART_SMART_IDLE_EN;
	writel(regval, &uart_base->uartsyscfg);
	debug("Smart Idle disabled:\n");
	
	debug("Done uart_soft_reset(void) function /arch/arm/cpu/armv7/am335xx folder:\n");
}

And this is the post message when u-boot-spl is running;

Done TPS65910 PMIC congfiguration:

Setting MPU Frequency...
Setting MPU Frequency Successful.

Done am33xx_spl_board_init(void) funtion:
boot device - 65
boot device - 65
Jumping to spl_ymodem_load_image() function
Starting YMODEM Load Image:
CStarting s_init(void) function /arch/arm/cpu/armv7/am335xx folder:
Disbaling Watchdog /arch/arm/cpu/armv7/am335xx folder:
Done Disbaling Watchdog /arch/arm/cpu/armv7/am335xx folder:
Starting uart_soft_reset(void) function /arch/arm/cpu/armv7/am335xx folder:
uartsyscfg value is 0x8
Resetting UART module:

And also it didnt wait for the u-boot.img to be loaded into ram, it jump directly into s_init() and then hang at uart_soft_reset().

I removed the #define DBUG in am335x_evm.h and the post message becomes like this;

Done TPS65910 PMIC congfiguration:

Setting MPU Frequency...
Setting MPU Frequency Successful.

Done am33xx_spl_board_init(void) funtion:
boot device - 65
Jumping to spl_ymodem_load_image() function
Starting YMODEM Load Image:
CCCCCCxyzModem - CRC mode, 0(SOH)/363(STX)/0(CAN) packets, 8 retries
Loaded 370596 bytes
Load Image Done:
Exiting spl_ymodem_load_image() function
Jumping to U-Boot
Jumping to U-Boot Image:
Transferring Controll to U-Boot Image Location
image entry point: 0x80800000

In this case the u-boot-spl wait and load the u-boot.img successfully into ram (confirmed through CCS memory view) but after that it hangs.

Hi：

    did you solve the problem?how to?

thanks