riscvchisel

Unable to get the RoCC accelerator built with the default Accumulator example for zed board


Tried building the RoCC accelerator default accumulator example for zed board, but getting an error of "illegal instruction"

I tried the below config in the configs.scala file:-

class WithAccumRocc extends Config(
(pname,site,here) => pname match {
case RoccNMemChannels => 1
case RoccMaxTaggedMemXacts => 0
case BuildRoCC => {
Some((p: Parameters) =>
Module(new AccumulatorExample()(p.alterPartial({ case CoreName => "AccumRocc" }))))
}

}
)
class WithRoCCConfig extends Config(new WithAccumRocc ++ new DefaultFPGAConfig)

The bitstream was generated successfully but when i ran the dummy_rocc_test binary generated from the example given in riscv-isa-sim, i got the following error on the zed board.

root@zynq:~# ./fesvr-zynq pk /sdcard/Custom\ elfs/dummy_rocc 
z 0000000000000000 ra 0000000000010044 sp 000000000feffb10 gp 0000000000017880
tp 0000000000000000 t0 0000000000017178 t1 0000000000017178 t2 0000000000000000
s0 000000000feffb40 s1 0000000000000000 a0 0000000000000001 a1 000000000feffb48
a2 0000000000000000 a3 0000000000000000 a4 0000000000000000 a5 000000000000007b
a6 0000000000000000 a7 0000000000000001 s2 0000000000000000 s3 0000000000000000
s4 0000000000000000 s5 0000000000000000 s6 0000000000000000 s7 0000000000000000
s8 0000000000000000 s9 0000000000000000 sA 0000000000000000 sB 0000000000000000
t3 0000000000000000 t4 0000000000000000 t5 0000000000000000 t6 0000000000000000
pc 0000000000010168 va 0000000000010168 insn 0027e00b sr 8000000000003008
An illegal instruction was executed!

Any help here would be greatly appreciated.

P.S. :- The dummy_rocc_test example is working fine with spike and has been compiled with riscv64-unknown-elf-gcc


Solution

  • Hello guys this issue has been resolved, once the change was made the rocket needs to be built with the new pga configuration and the vivid project must also be updated accordingly in order to generate the new bitstream.