TMDXSK437X: Boot from uart and loading application via uart

Thanks for the fast response

your information indeed helped me a lot

a quick complementary question :

in the links you sent , I found the following table : 

while the GPEVM supports boot from uart , the SK does not.

looking at the schematics , the both use DDRs , but the GPEVM DDR is twice the side as the SK DDR (other than that they seems the same)

does the table refers only for the HW limitations : for example @ the starter kit I had to manipulated the sysboot resistors , or does it refers to boot loader software?

or from a different angle : Can I use the boortoader image "bootloader_boot_uart_a9host_debug.bin" on the SK ? 

or am I missing something ?

Hi inno,

inno said:

Can I use the boortoader image "bootloader_boot_uart_a9host_debug.bin" on the SK ? 

This is a good question. I haven't tried to use the UART bootloader on an AM437x StarterKit EVM.

inno said:

while the GPEVM supports boot from uart , the SK does not.

I checked the SYSBOOT pin connections on the hardware platforms in the table.

• The default SYSBOOT resistor connections on the AM437x IDK and SK don't provide UART as a boot source, and these platforms don't support UART boot.
• The default SYSBOOT resistor connections on the AM335x SK and BBB provide UART as a boot source, and these platforms support UART boot.
• The AM335x ICEv2 SYSBOOT resistors (and jumper) allow selecting UART0 as a boot source, but UART0 is connected to a CAN transceiver. This platform doesn't support UART boot.
• The SYSBOOT connections for the remaining is configurable via DIP switches, and UART boot is supported.

inno said:

but the GPEVM DDR is twice the side as the SK DDR

The smaller DDR size shouldn't be a problem, as long as the application image isn't loaded to DDR that does exist on the platform. Inspecting the bootloader source code, I see the following:

            main()
                SBLPlatformConfig()
                    SBLPlatformDdrInit()
                        else if(BOARD_EVMSK == boardId) /* For IDK EVM - DDR3 */
                        {
                            ddrCfg = EVMSK_DDR3_CONFIG;
                            memType = SBL_PLATFORM_MEM_TYPE_DDR3;
                        }

Hence I think bootloader should properly configure DDR for the StarterKit.

I don't have an SK board, but I tried loading bootloader_boot_uart_a9host_debug.out and bootloader_boot_uart_a9host_release.out to an AM437x IDK via JTAG to see if it would work.  The loader unexpectedly throws an error:

CortexA9: Trouble Writing Memory Block at 0x402f0074 on Page 0 of Length 0x7ff0: (Error -1065 @ 0x3D5A) Unable to access device memory. Verify that the memory address is in valid memory. If error persists, confirm configuration, power-cycle board, and/or try more reliable JTAG settings (e.g. lower TCLK). (Emulation package 8.4.0.00006)

This memory is listed as unavailable in the TRM, but I don't see anything linked to this memory range in the the bootloader .map files. I'll try to figure this out in the next few days.

Can you see if you can load bootloader_boot_uart_a9host_debug.out to your SK board? If you can load the bootloader, then you can debug it like any other application. Please see: https://software-dl.ti.com/processor-sdk-rtos/esd/docs/06_03_00_106/AM437X/rtos/index_Foundational_Components.html#software-debug-steps, Emulator based debugging of boot.

Regards,
Frank