Hi,
How do you store an entire program in external sdram, is it possible to declare all sections in the linker script to sdram (eventually the boot section to bram) ? Or is there another way to get all data in the sdram ?
thanks
Tom
Hi,
How do you store an entire program in external sdram, is it possible to declare all sections in the linker script to sdram (eventually the boot section to bram) ? Or is there another way to get all data in the sdram ?
thanks
Tom
Which MCU, DSP, or CPU are you using? Is it part of some other system, for example a Basic Stamp?
Most MCU's use external SDRAM for data storage not progam storage. A lot of DSP's use external RAM for both data and program storage. CPU's are pretty much all external RAM for both data and program space.
I am using a memec development board (2vp4) with a virtex II pro fpga with powerpc. On the board 32 Mb sdram is available. At this point we use the bram to store our programs that's 64k. But what if we want to implement an rtos ?
Tom
Atmels Linux port does just that, so I assume that this is pretty standard for Embedded (ARM) Linux.
At boot, the internal BootROM looks for the second level boot. This is linked to internal SRAM; and is loaded by the RomBoot from the SPI Dataflash. After loading the CPU jumps to the SRAM address 0.
The third level boot (U-Boot) is linked to SRAM and loaded from SPI dataflash by the second level boot. U-Boot is compressed, so the image is decompressed in the process.
U-Boot will run the "bootcmd" script which loads Linux from SPI Dataflash to SDRAM and decompresses the kernel and the RAMDrive. Both the Kernel and the RAMdrive are linked to SDRAM.
So in order to do what you want, you need to have one or more levels of boot which are executed to load your SDRAM image.
-- Best Regards Ulf at atmel dot com
Sorry I don't know anything about that board. The
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