xref: /plan9-contrib/sys/src/boot/vt5/words (revision 98a68993d685eb89080b5d73dba0a8f0a226848c)
1This bootstrap is intended to load a Plan 9 kernel via bootp and tftp
2into a Xilinx Virtex 5 ML510 board.  Most of its source is in ../vt4.
3The mkfile generates an elf file which is then fed into the Xilinx CAD
4tool to generate a bitstream for loading into the FPGA on the ML510.
5
6This bootstrap will almost certainly not work for you without some
7changes.  In particular, the addresses of the I/O registers in
8physmem.h will have to be changed to match yours and you'll need to
9make sure that they are mapped if you have more than 512K of them.
10
11Because of pecularities of the PowerPC 440, there's a `micro
12bootstrap' in microboot.s that kicks everything off.  The bootstrap
13runs with the MMU on, because it's always on on a 440.
14
15This bootstrap does not use dma but in principle it could, by
16replacing calls to fifocpy with calls to dmacpy.  dma is one more
17thing that could go wrong, so we ended up using the cpu to copy words
18to and from ethernet fifos.
19
20This code runs in high memory (above 0xfffe0000) and its global data
21is thus in sram.
22