Hang problem when switching UART debug port from UART3 to UART2

Luan Le said:

During the XLDR/EBOOT/NK.BIN download, there were debug outputs coming from UART2.  However, the EVM hangs at "Launch Windows CE image by jumping to 0x8001XXXX..."

When you say it hangs, do you mean that WinCE never finishes booting and you see nothing on the LCD, or just that the output on the UART2 stops happening? It sounds like what you are doing here is reasonable, so my initial thought would be that there is just some problem with the serial port configuration and not WinCE as a whole, though I am not intimately familiar with the BSP so I will have to leave it to the BSP folks to comment further.

Hi Bernie,

You are right.  WinCe never finishes booting, output from UART2 stops, and nothing is shown on the LCD.

We are about to go to production testing of WinCE and our OMAP custom board, so it is very critical to us to have this problem fixed asap.

I appreciate all the helps from the TI's team.

Regards,

Luan

Luan,

I am able to reproduce the issue, the problem is caused by debug serial clock is not enabled for UART1/UART2 in OAL. The OAL code use hard coded value for UART3.

One way to solve the issue is to keep debugserial clock enabled in Eboot.

Here are the changes you will need :

1. Change debug port to UART1/UART2 in bspcfg.c

2. Enable corresponding UART PAD configurations in XLDR.(PinMuxSetup() in platform.c)

3. Enable corresponding UART PAD configuration in OAL (init.c)

    ConfigurePadArray(BSPGetDevicePadInfo(OMAP_DEVICE_UART2));

4. enable debug serial clock before launch the Kernel.(OEMLaunch() in main.c)

    EnableDeviceClocks(BSPGetDebugUARTConfig()->dev, TRUE);

    JumpTo(OALVAtoPA((UCHAR*)launch));

If debug serial is not used (Retail message is disabled from Eboot menu), then the clock for debug serial port will be disabled in Init.c.

Thanks,

Tao

Hi Tao,

Following your instructions, the hang problem is now fixed when using UART2 for debug serial.  However, from somewhere during the booting, RETAILMSG and OALMSG stop working.  For instance, the lines below are no longer output :

SDHC: CPU revision 0x6
Init Touch Controller with GPIO 162 and INT 290

even though in sdhc.cpp,

"SDHC: CPU revision 0x%x\r\n", m_dwCPURev));

and in touchscreen.cpp,

"Init Touch Controller with GPIO %d and INT %d\r\n", s_TouchDevice.nPenGPIO, s_TouchDevice.nPenIRQ));

When UART3 is used, these two lines are output.

Hi Tao,

Thank you very much for the tip - yes, I have UART2 checked in my catalog.

I unchecked it and the COM2 debug is working now.

Thanks for your help,

Luan

Luan,

I am glad the problem is solved.  I am not sure what solution you have used, I just want to remind you that I have added a cleaner way to solve the issue on the wiki FAQ page. We will use that approach in ARM_A8 BSP.

Thanks,

Tao

Hi Tao,

I am using the (b) option in which startup.s is modified to pass the debug port to EnableDebugSerialClock().  I also thought it is cleaner way.

Thanks,

Luan