• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 100 subscribers
  • Views 375 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Unable to run USB0 code from internal RAM?

Vishvajeet Godse
Intellectual 705 points


I have to develop my own boot-loader, that will run from internal RAM.
In boot-loader application I have to implement firmware upgrade functionality as well.
for that I have to read application/firmware image from PC using USB and write it to flash.
Currently I am booting from UART0(getting binary from UART) using XMODEM interface.
My main intenetion is to get the application image from PC using USB and write it into FLASH.

I don't want to run this boot-loader code from DDR because in final product,
my boot-loader will get copied/booted from NAND flash by '(On chip)ROM boot code' into SRAM(Internal RAM).

So My current problem is I am unable to read data over USB from PC.

While debugging I found following observation

1.Code get stuck at following function

MMUInit((unsigned int*)pageTable);

this function is called in MMUConfigAndEnable() function.

2. When I disable the MMUConfigAndEnable() function.
I dont get any timer ISR used for USB.

3. When I run the same code from DDR everything works very well
But when I disable the MMUConfigAndEnable() function.
Same is observed as mentioned in points 1 and 2.

So I think MMUConfigAndEnable() function is not working properly in internal RAM(SRAM)

Hardware used - EVM-SK(rev 1.2C)

TI startWare version - AM335X_StarterWare_02_00_01_01

Please suggest me solution.

  • 0
    Intellectual 705 points
    Hi,
    I Solved MMUConfigAndEnable() problem,now I am able to run code using MMU,now its working fine.but another problem is remains their,SRAM Code(Starterware bootloader)doesnt generate timer interrupt;I debugged code and I observed that it doesnt jumps to ISR.might be due to this usb enemeration process is not happening,So Please tell me how can I modify code so that I can jump to ISR routine.
    I checked code by changing stack size but its also not working.
    Please guide me how can I execute ISR inside SRAM.

    Regards,
    Vishvajeet