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Merge pull request #2098 from enjoy-digital/urv 

Add initial uRV CPU support.
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enjoy-digital 2024-10-17 19:45:44 +02:00 committed by GitHub
parent c82fddf635 5f463dba87
commit c1225736a8
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8 changed files with 348 additions and 1 deletions
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3
CHANGES.md
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@ -6,7 +6,8 @@
[> Added
--------
- cpu/zynqmp : Added SGMII support via PL andoptional PTP (#2095).
- liteeth/phy : Improved 1000BaseX/2500BaseX PCS/PHYs (https://github.com/enjoy-digital/liteeth/pull/174).
- liteeth/phy : Improved 1000BaseX/2500BaseX PCS/PHYs (https://github.com/enjoy-digital/liteeth/pull/174).*
- cpu/urv : Added uRV CPU support (RISC-V CPU use in White Rabbit project).
[> Changed
----------

1
litex/soc/cores/cpu/urv/__init__.py Normal file
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from litex.soc.cores.cpu.urv.core import uRV

4
litex/soc/cores/cpu/urv/boot-helper.S Normal file
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.section .text, "ax", @progbits
.global boot_helper
boot_helper:
jr x13

238
litex/soc/cores/cpu/urv/core.py Normal file
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#
# This file is part of LiteX.
#
# Copyright (c) 2024 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause
import os
from migen import *
from litex.gen import *
from litex.soc.interconnect import stream
from litex.soc.interconnect import wishbone
from litex.soc.cores.cpu import CPU, CPU_GCC_TRIPLE_RISCV32
# Variants -----------------------------------------------------------------------------------------
CPU_VARIANTS = {
"standard": "urv",
}
# GCC Flags ----------------------------------------------------------------------------------------
GCC_FLAGS = {
# /------------ Base ISA
# | /------- Hardware Multiply + Divide
# | |/----- Atomics
# | ||/---- Compressed ISA
# | |||/--- Single-Precision Floating-Point
# | ||||/-- Double-Precision Floating-Point
# i macfd
"standard": "-march=rv32i2p0_m -mabi=ilp32",
}
# uRV ------------------------------------------------------------------------------------------
class uRV(CPU):
category = "softcore"
family = "riscv"
name = "urv"
human_name = "urv"
variants = CPU_VARIANTS
data_width = 32
endianness = "little"
gcc_triple = CPU_GCC_TRIPLE_RISCV32
linker_output_format = "elf32-littleriscv"
nop = "nop"
io_regions = {0x8000_0000: 0x8000_0000} # Origin, Length.
# GCC Flags.
@property
def gcc_flags(self):
flags = GCC_FLAGS[self.variant]
flags += " -D__urv__ "
return flags
def __init__(self, platform, variant="standard"):
self.platform = platform
self.variant = variant
self.human_name = f"uRV-{variant.upper()}"
self.reset = Signal()
self.ibus = ibus = wishbone.Interface(data_width=32, address_width=32, addressing="byte")
self.dbus = dbus = wishbone.Interface(data_width=32, address_width=32, addressing="byte")
self.periph_buses = [ibus, dbus] # Peripheral buses (Connected to main SoC's bus).
self.memory_buses = [] # Memory buses (Connected directly to LiteDRAM).
# uRV Signals.
# ------------
im_addr = Signal(32)
im_rd = Signal()
im_data = Signal(32)
im_valid = Signal()
dm_addr = Signal(32)
dm_data_s = Signal(32)
dm_data_l = Signal(32)
dm_data_select = Signal(4)
dm_store = Signal()
dm_load = Signal()
dm_load_done = Signal()
dm_store_done = Signal()
# uRV Instance.
# -------------
self.cpu_params = dict(
# Parameters.
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,
p_g_with_hw_debug = 0,
p_g_with_ecc = 0,
p_g_with_compressed_insns = 0,
# Clk / Rst.
i_clk_i = ClockSignal("sys"),
i_rst_i = ResetSignal("sys") | self.reset,
# Instruction Mem Bus.
o_im_addr_o = im_addr,
o_im_rd_o = im_rd,
i_im_data_i = im_data,
i_im_valid_i = im_valid,
# Data Mem Bus.
o_dm_addr_o = dm_addr,
o_dm_data_s_o = dm_data_s,
i_dm_data_l_i = dm_data_l,
o_dm_data_select_o = dm_data_select,
o_dm_store_o = dm_store,
o_dm_load_o = dm_load,
i_dm_load_done_i = dm_load_done,
i_dm_store_done_i = dm_store_done,
)
# uRV Instruction Bus.
# --------------------
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")
)
)
# uRV Data Bus.
# -------------
self.dm_fifo = dm_fifo = stream.SyncFIFO(
layout = [("addr", 32), ("we", 1), ("data", 32), ("sel", 4)],
depth = 16,
)
self.comb += [
dm_fifo.sink.valid.eq(dm_store | dm_load),
dm_fifo.sink.we.eq(dm_store),
dm_fifo.sink.addr.eq(dm_addr),
dm_fifo.sink.data.eq(dm_data_s),
dm_fifo.sink.sel.eq(dm_data_select),
]
self.dm_fsm = dm_fsm = FSM(reset_state="IDLE")
dm_fsm.act("IDLE",
If(dm_fifo.source.valid,
If(dm_fifo.source.we,
NextState("WRITE")
).Else(
NextState("READ")
)
)
)
dm_fsm.act("WRITE",
dbus.stb.eq(1),
dbus.cyc.eq(1),
dbus.we.eq(1),
dbus.adr.eq(dm_fifo.source.addr),
dbus.sel.eq(dm_fifo.source.sel),
dbus.dat_w.eq(dm_fifo.source.data),
If(dbus.ack,
dm_fifo.source.ready.eq(1),
dm_store_done.eq(1),
NextState("IDLE")
)
)
dm_fsm.act("READ",
dbus.stb.eq(1),
dbus.cyc.eq(1),
dbus.we.eq(0),
dbus.adr.eq(dm_fifo.source.addr),
dbus.sel.eq(dm_fifo.source.sel),
If(dbus.ack,
dm_fifo.source.ready.eq(1),
dm_load_done.eq(1),
dm_data_l.eq(dbus.dat_r),
NextState("IDLE")
)
)
# Add Verilog sources.
# --------------------
self.add_sources(platform, variant)
def set_reset_address(self, reset_address):
assert reset_address == 0
self.reset_address = reset_address
@staticmethod
def add_sources(platform, variant):
if not os.path.exists("urv-core"):
os.system(f"git clone https://ohwr.org/project/urv-core/")
vdir = "urv-core/rtl"
platform.add_verilog_include_path("urv-core/rtl")
platform.add_sources([
"urv-core/rtl/urv_cpu.v",
"urv-core/rtl/urv_exec.v",
"urv-core/rtl/urv_fetch.v",
"urv-core/rtl/urv_decode.v",
"urv-core/rtl/urv_regfile.v",
"urv-core/rtl/urv_writeback.v",
"urv-core/rtl/urv_shifter.v",
"urv-core/rtl/urv_multiply.v",
"urv-core/rtl/urv_divide.v",
"urv-core/rtl/urv_csr.v",
"urv-core/rtl/urv_timer.v",
"urv-core/rtl/urv_exceptions.v",
"urv-core/rtl/urv_iram.v",
"urv-core/rtl/urv_ecc.v",
])
def do_finalize(self):
self.specials += Instance("urv_cpu", **self.cpu_params)

75
litex/soc/cores/cpu/urv/crt0.S Normal file
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#define MIE_MEIE 0x800
.global _start
_start:
j reset_vector
reset_vector:
la sp, _fstack
la t0, trap_vector
csrw mtvec, t0
// initialize .data
la t0, _fdata
la t1, _edata
la t2, _fdata_rom
1: beq t0, t1, 2f
lw t3, 0(t2)
sw t3, 0(t0)
addi t0, t0, 4
addi t2, t2, 4
j 1b
2:
// initialize .bss
la t0, _fbss
la t1, _ebss
1: beq t0, t1, 3f
sw zero, 0(t0)
addi t0, t0, 4
j 1b
3:
// enable external interrupts
li t0, MIE_MEIE
csrs mie, t0
call main
1: j 1b
trap_vector:
addi sp, sp, -16*4
sw ra, 0*4(sp)
sw t0, 1*4(sp)
sw t1, 2*4(sp)
sw t2, 3*4(sp)
sw a0, 4*4(sp)
sw a1, 5*4(sp)
sw a2, 6*4(sp)
sw a3, 7*4(sp)
sw a4, 8*4(sp)
sw a5, 9*4(sp)
sw a6, 10*4(sp)
sw a7, 11*4(sp)
sw t3, 12*4(sp)
sw t4, 13*4(sp)
sw t5, 14*4(sp)
sw t6, 15*4(sp)
call isr
lw ra, 0*4(sp)
lw t0, 1*4(sp)
lw t1, 2*4(sp)
lw t2, 3*4(sp)
lw a0, 4*4(sp)
lw a1, 5*4(sp)
lw a2, 6*4(sp)
lw a3, 7*4(sp)
lw a4, 8*4(sp)
lw a5, 9*4(sp)
lw a6, 10*4(sp)
lw a7, 11*4(sp)
lw t3, 12*4(sp)
lw t4, 13*4(sp)
lw t5, 14*4(sp)
lw t6, 15*4(sp)
addi sp, sp, 16*4
mret

4
litex/soc/cores/cpu/urv/irq.h Normal file
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#ifndef __IRQ_H
#define __IRQ_H
#endif /* __IRQ_H */

19
litex/soc/cores/cpu/urv/system.h Normal file
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#ifndef __SYSTEM_H
#define __SYSTEM_H
#ifdef __cplusplus
extern "C" {
#endif
__attribute__((unused)) static void flush_cpu_icache(void){}; /* No instruction cache */
__attribute__((unused)) static void flush_cpu_dcache(void){}; /* No instruction cache */
void flush_l2_cache(void);
void busy_wait(unsigned int ms);
void busy_wait_us(unsigned int us);
#ifdef __cplusplus
}
#endif
#endif /* __SYSTEM_H */

5
litex/soc/integration/builder.py
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@ -339,6 +339,11 @@ class Builder:
# 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