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soc/cores/cpu/urv: Move ROM init to builder and allow switching betwe…
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…en classical ROM or ROM integrated in CPU.
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enjoy-digital committed Oct 17, 2024
1 parent 9449d25 commit aab8912
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Showing 2 changed files with 39 additions and 42 deletions.
76 changes: 34 additions & 42 deletions litex/soc/cores/cpu/urv/core.py
Original file line number Diff line number Diff line change
Expand Up @@ -86,8 +86,8 @@ def __init__(self, platform, variant="standard"):
# -------------
self.cpu_params = dict(
# Parameters.
p_g_timer_frequency = 1000,
p_g_clock_frequency = 100000000,
p_g_timer_frequency = 1000, # FIXME.
p_g_clock_frequency = 100000000, # FIXME.
p_g_with_hw_div = 1,
p_g_with_hw_mulh = 1,
p_g_with_hw_mul = 1,
Expand Down Expand Up @@ -119,47 +119,39 @@ def __init__(self, platform, variant="standard"):

# uRV Instruction Bus.
# --------------------
from litex.soc.integration.common import get_mem_data

try:
# FIXME.
rom_init = get_mem_data("build/sim/software/bios/bios.bin",
data_width = 32,
endianness = "little"
if True:
from litex.soc.integration.common import get_mem_data
self.rom = Memory(32, depth=131072//4)
self.rom_port = self.rom.get_port()

self.sync += im_valid.eq(1),
self.comb += [
self.rom_port.adr.eq(im_addr[2:]),
im_data.eq(self.rom_port.dat_r),
]
else:
# FIXME: Try to implement im_bus -> Wishbone correctly (if possible).
im_addr_d = Signal(32, reset=0xffffffff)
self.sync += im_addr_d.eq(im_addr)
self.i_fsm = i_fsm = FSM(reset_state="IDLE")
i_fsm.act("IDLE",
If(im_addr != im_addr_d,
NextValue(im_valid, 0),
NextState("READ")
)
)
i_fsm.act("READ",
ibus.stb.eq(1),
ibus.cyc.eq(1),
ibus.we.eq(0),
ibus.adr.eq(im_addr),
ibus.sel.eq(0b1111),
If(ibus.ack,
NextValue(im_valid, 1),
NextValue(im_data, ibus.dat_r),
NextState("IDLE")
)
)
except:
rom_init = []
rom = Memory(32, depth=131072//4, init=rom_init)
rom_port = rom.get_port()
self.specials += rom, rom_port

self.sync += im_valid.eq(1),
self.comb += [
rom_port.adr.eq(im_addr[2:]),
im_data.eq(rom_port.dat_r),
]

# im_addr_d = Signal(32, reset=0xffffffff)
# self.sync += im_addr_d.eq(im_addr)
# self.i_fsm = i_fsm = FSM(reset_state="IDLE")
# i_fsm.act("IDLE",
# If(im_addr != im_addr_d,
# NextValue(im_valid, 0),
# NextState("READ")
# )
# )
# i_fsm.act("READ",
# ibus.stb.eq(1),
# ibus.cyc.eq(1),
# ibus.we.eq(0),
# ibus.adr.eq(im_addr),
# ibus.sel.eq(0b1111),
# If(ibus.ack,
# NextValue(im_valid, 1),
# NextValue(im_data, ibus.dat_r),
# NextState("IDLE")
# )
# )

# uRV Data Bus.
# -------------
Expand Down
5 changes: 5 additions & 0 deletions litex/soc/integration/builder.py
Original file line number Diff line number Diff line change
Expand Up @@ -339,6 +339,11 @@ def _initialize_rom_software(self):
# Initialize SoC with with BIOS data.
self.soc.init_rom(name="rom", contents=bios_data)

# FIXME: Remove uRV ROM Init Workaround.
from litex.soc.cores.cpu.urv import uRV
if isinstance(self.soc.cpu, uRV):
self.soc.cpu.rom.init = bios_data

def build(self, **kwargs):
# Pass Output Directory to Platform.
self.soc.platform.output_dir = self.output_dir
Expand Down

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