Hello All,
I figured out how to run an application from external memory in Xilinx. I have EDK ver 8.2.01i and an ML403 board. What you do is "Mark to init BRAMs" on the default bootloop app in the Applications window pane, update your bitstream and then load it into the board using iMPACT. Change your linker script using "Generate Link Script" for your large application and set the .text section to SRAM. Rebuild your app.
You also have to set the .boot section (0x00000010) to SRAM. I was able to follow how to use XMD and GDB by reading the est_rm.pdf, but I couldn't find this information on how to set up your linker script in the installed help files that come with the software, or in the .pdf manuals that also come with the software.
It really seems to me that Xilinx could just mention that in their manuals and online help rather than make people guess or dig through examples.
Once I was running in external memory, I found I had to set the view to "Mixed" (source and assembly) and I could only put the breakpoints on the assembly code. I'm happy now, but this shouldn't have been such a guessing game or scavenger hunt.
Look at Using SDK file:///C:/EDK/doc/usenglish/help/platform_studio/platform_studio.htm#html/ps_p_app_using_ps_sdk.htm Look down on left pane for "Running an Application from External Memory". All it says is "The bitstream must first be initialized with a bootloop, and the FPGA configured with this information." Downloading a Design Using XMD: file:///C:/EDK/doc/usenglish/help/platform_studio/platform_studio.htm#html/ps_p_app_using_ps_sdk.htm "Use dow to download the software executable." and then they leave you to follow the rest of the documentation on how to set up XMD and GDB. You don't even have to do that latter; GDB will load your code for you when you click Run.
It really seems to me that they could put in what you need to know, and leave out what you don't need to do...