This makes the control bus currently going out of "soc" towards
litedram more generic for external IO devices added by the
top-level rather than inside the SoC proper.
This is mostly renaming of signals and a small change on how the
address decoder operates, using a separate "cascaded" decode for
the external IOs.
We make the region 0xc8nn_nnnn be the "external IO" region for
now.
This will make it easier / cleaner to add more external devices.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
That way the top-level's don't need to assign them
Also remove generics that are set to the default anyways
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This require the s25fl128s.vhd flash model and FMF libraries,
which will be built when passed to the Makefile via the
FLASH_MODEL_PATH argument. Otherwise a dummy module is used
which ties MISO to '1'.
The model isn't included as I'm not sure its licence (GPL) is
at this point, but it can be obtained from
https://github.com/ozbenh/microspi
FLASH_MODEL_PATH=<path to microspi>/model
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We still had some wires bringing an extra serial port out of
litedram for the built-in riscv processor. This is all gone now
so take them out.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds an option to disable the main BRAM and instead copy a
payload stashed along with the init code in the secondary BRAM
into DRAM and boot from there
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds a simulated litedram model along with the necessary
Makefile gunk to verilate it and wrap it for use by ghdl.
The core_dram_tb test bench is a variant of core_tb with
LiteDRAM simulated. It's not built by default, an explicit
make core_dram_tb
is necessary as to not require verilator to be installed for
the normal build process (also it's slow'ish).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Benjamin Herrenschmidt