There are two details here, one of them important. (1) The System ACE is one configuration option; you can also download a new bit file via the JTAG cable.
(2) Whether the bit file is obtained via System ACE or JTAG, the FPGA is initialized. This includes populating the block RAM. Note that your block RAM will almost certainly not be big enough to contain your Linux kernel. Sizes vary but in my experience they are measured in kilobytes -- e.g. 4KB to 64KB. For this reason, it is preferable to have the ELF file that is contained in your bitstream be a *small* executable that can fit in the block RAM. This small executable can *find* a larger executable (e.g. the Linux kernel image), from a flash device, compact flash, TFTP, etc., then load and run it. -----Original Message----- From: Scott Anderson [mailto:[EMAIL PROTECTED] Sent: Monday, June 02, 2003 1:36 PM To: ??? Cc: linuxppc-embedded at lists.linuxppc.org Subject: Re: bootstrap of virtex-ii pro eval board ML300 On Saturday, May 31, 2003, at 06:14 PM, ??? wrote: ?We have subscribe the ML300 demo board from xilinx,but it needs several > months to arrive. I remember someone has done some work in virtex II > pro demo boards.Will someone tell me some details about the bootstrap's > procedure of such systems. A quick high level description from my understanding: There is a piece of Xilinx hardware called System ACE which reads a rotary switch to determine which of eight possible files it should load from the first partition (which must be a FAT partition) of the IBM MicroDrive. System ACE initializes the FPGA, processor and memory by using the contents of this file to manipulate the JTAG chain. Xilinx provides tools so that you can combine an ELF image (e.g. a Linux kernel) with an FPGA bitstream so that when the processor comes out of reset, your image is already loaded into memory ready to go. For your development, I would suggest using a JTAG debugger (specifically, the Abatron BDI2000) to load your kernel into memory so that you don't have to keep mucking with the MicroDrive. Having the BDI2000 also gives you a good tool for debugging the kernel and drivers. Scott ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
