Re: to test SDRAM

The bootloader nearly always runs from RAM, not flash. One reason is that
you can't reflash the bootloader if it is running from flash. Instead of
finding all the things you'll need to change in order to run from flash,
just do your RAM test in assembly code during system initialization.

Not too much point in doing a RAM test well after the system is up and
running, already using the RAM...

--
Dean Ramsier - eMVP
BSQUARE Corporation


"Jeyanthi Jayakumar" <JeyanthiJayakumar@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:D9681EEB-22E5-4D57-933A-F66B5CF94D00@xxxxxxxxxxxxxxxx
Hi everyone,

I am new to WinCE5.0 and i have understood some of things from PB and the
code. Now i have to test the SDRAM by writing some values and reading it
back, so that i shall verify it is working. For this we have the code
modified in in Blcommon.c Bootloader main function, where i have included
writing 0xAA to SDRAM and reading it back.

// relocate globals to RAM
if (!KernelRelocate (pTOC))
{
// spin forever
HALT (BLERR_KERNELRELOCATE);
}

// (1) Init debug support. We can use OEMWriteDebugString afterward.
if (!OEMDebugInit ())
{
// spin forever
HALT (BLERR_DBGINIT);
}

// output banner
EdbgOutputDebugString (NKSignon, CURRENT_VERSION_MAJOR,
CURRENT_VERSION_MINOR);

// (3) initialize platform (clock, drivers, transports, etc)
if (!OEMPlatformInit ())
{
// spin forever
HALT (BLERR_PLATINIT);
}

// system ready, preparing for download
EdbgOutputDebugString ("System ready!\r\nPreparing for
download...\r\n");
I have added my code in the function after the above line.

In startup.s OALstartup function, there they are copying the file from
FLASH
to RAM and start running from RAM and after that they are maping the
cached
and uncached memory. I don't want to copy the file to SDRAM so i have
commented till BUILDTTB that is till the line

add r11, pc, #g_oalAddressTable - (.+8)

But if i do all these i am not getting any debug messages from the UART
and
i am not sure whether the processor is running or hanging.

Can anyone tell me what to do in startup.s or somewhere, to run the Eboot
in
Flash itself instead of copying to RAM.

Kindly reply me ASAP
Thanks in advance.



.

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