This program is no longer needed.
The `openocd_vexriscv` package natively supports `etherbone`, and now
that the vexriscv debug module is available on Wishbone instead of as a
CSR, this module no longer works.
This change simplifies both tooling (because there is one fewer program
to run) and integration (because you don't need to modify your CSRs
anymore, just `register_mem()`.)
Signed-off-by: Sean Cross <sean@xobs.io>
If the CPU is resetting during a Wishbone transfer, assert the ERR line.
Because the resetOut line is likely multiple cycles long, this should
give Wishbone enough time to finish its transfer, which will cause d.stb
and i.stb to go to 0, which will return d_err and i_err to 0.
Signed-off-by: Sean Cross <sean@xobs.io>
By placing the VexRiscv debug bus on the Wishbone bus, the Etherbone
core can access 32-bit values directly from the core. Additionally,
both reading and writing are supported without the need to do a SYNC
register as before.
Additionally, the address of the Wishbone bus won't move around anymore,
as it's fixed when doing `self.register_mem()`.
Signed-off-by: Sean Cross <sean@xobs.io>
CSR access widths can be different from register widths. 8-bit
registers are common.
The runtime-generated `read()` and `write()` functions handle this
mapping correctly. When direct register accesses are handled, this
mapping is lost.
Use the accessor functions rather than directly accessing the memory
addresses, so that we work on platforms other than 32-bit-wide.
Signed-off-by: Sean Cross <sean@xobs.io>
The REFRESH register accepts an 8-bit address and determines which
register to refresh. Since there are only two addresses currently in
use, this register can be either 0x00 or 0x04.
A refactor replaced the compare with one that checked for any 0 bits.
Since both 0x00 and 0x04 have 0 bits, this check always evaluated as
true, causing the logic to always refresh the CORE register.
Replace this check with an explicit check for 0x00.
Signed-off-by: Sean Cross <sean@xobs.io>
Add the vexriscv_debug program to the list of scripts created when
installing this module. This program is a simple bridge that allows
openocd to talk to the vexriscv core so it can be debugged.
Signed-off-by: Sean Cross <sean@xobs.io>
Florent Kermarrec
Peter Gielda
Sean Cross