initial SERV integration.

diff --git a/litex/soc/cores/cpu/__init__.py b/litex/soc/cores/cpu/__init__.py
index db9fdab7b8a5b56507190aeb3151f297313fad81..d0b11a50efd3ddd103d161f85cbd02890122a41a 100644 (file)
--- a/litex/soc/cores/cpu/__init__.py
+++ b/litex/soc/cores/cpu/__init__.py
@@ -37,17 +37,19 @@ from litex.soc.cores.cpu.minerva import Minerva
 from litex.soc.cores.cpu.rocket import RocketRV64
 from litex.soc.cores.cpu.microwatt import Microwatt
 from litex.soc.cores.cpu.blackparrot import BlackParrotRV64
+from litex.soc.cores.cpu.serv import SERV
 
 CPUS = {
-    "None"       : CPUNone,
-    "lm32"       : LM32,
-    "mor1kx"     : MOR1KX,
-    "picorv32"   : PicoRV32,
-    "vexriscv"   : VexRiscv,
-    "minerva"    : Minerva,
-    "rocket"     : RocketRV64,
-    "microwatt"  : Microwatt,
+    "None"        : CPUNone,
+    "lm32"        : LM32,
+    "mor1kx"      : MOR1KX,
+    "picorv32"    : PicoRV32,
+    "vexriscv"    : VexRiscv,
+    "minerva"     : Minerva,
+    "rocket"      : RocketRV64,
+    "microwatt"   : Microwatt,
     "blackparrot" : BlackParrotRV64,
+    "serv"        : SERV
 }
 
 # CPU Variants/Extensions Definition ---------------------------------------------------------------

diff --git a/litex/soc/cores/cpu/serv/__init__.py b/litex/soc/cores/cpu/serv/__init__.py
new file mode 100644 (file)
index 0000000..b46284a
--- /dev/null
+++ b/litex/soc/cores/cpu/serv/__init__.py
@@ -0,0 +1 @@
+from litex.soc.cores.cpu.serv.core import SERV

diff --git a/litex/soc/cores/cpu/serv/core.py b/litex/soc/cores/cpu/serv/core.py
new file mode 100644 (file)
index 0000000..8128fda
--- /dev/null
+++ b/litex/soc/cores/cpu/serv/core.py
@@ -0,0 +1,91 @@
+# This file is Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
+
+# License: BSD
+
+import os
+
+from migen import *
+
+from litex.soc.interconnect import wishbone
+from litex.soc.cores.cpu import CPU
+
+
+CPU_VARIANTS = ["standard"]
+
+
+class SERV(CPU):
+    name                 = "serv"
+    data_width           = 32
+    endianness           = "little"
+    gcc_triple           = ("riscv64-unknown-elf", "riscv32-unknown-elf", "riscv-none-embed",
+                            "riscv64-linux", "riscv-sifive-elf", "riscv64-none-elf")
+    linker_output_format = "elf32-littleriscv"
+    io_regions           = {0x80000000: 0x80000000} # origin, length
+
+    @property
+    def gcc_flags(self):
+        flags =  "-march=rv32i "
+        flags += "-mabi=ilp32 "
+        flags += "-D__serv__ "
+        return flags
+
+    def __init__(self, platform, variant="standard"):
+        assert variant in CPU_VARIANTS, "Unsupported variant %s" % variant
+        self.platform  = platform
+        self.variant   = variant
+        self.reset     = Signal()
+        self.ibus      = ibus = wishbone.Interface()
+        self.dbus      = dbus = wishbone.Interface()
+        self.buses     = [self.ibus, dbus]
+        self.interrupt = Signal(32)
+
+        # # #
+
+        self.cpu_params = dict(
+            # clock / reset
+            i_clk   = ClockSignal(),
+            i_i_rst = ResetSignal(),
+
+            # timer irq
+            i_i_timer_irq = 0,
+
+            # ibus
+            o_o_ibus_adr = ibus.adr,
+            o_o_ibus_cyc = ibus.cyc,
+            i_i_ibus_rdt = ibus.dat_r,
+            i_i_ibus_ack = ibus.ack,
+
+
+            # dbus
+            o_o_dbus_adr = dbus.adr,
+            o_o_dbus_dat = dbus.dat_w,
+            o_o_dbus_sel = dbus.sel,
+            o_o_dbus_we  = dbus.we,
+            o_o_dbus_cyc = dbus.cyc,
+            i_i_dbus_rdt = dbus.dat_r,
+            i_i_dbus_ack = dbus.ack,
+        )
+        self.comb += [
+            ibus.stb.eq(ibus.cyc),
+            dbus.stb.eq(dbus.cyc),
+        ]
+
+        # add verilog sources
+        self.add_sources(platform)
+
+    def set_reset_address(self, reset_address):
+        assert not hasattr(self, "reset_address")
+        self.reset_address = reset_address
+        self.cpu_params.update(p_RESET_PC=reset_address)
+
+    @staticmethod
+    def add_sources(platform):
+        # FIXME: add SERV as submodule
+        os.system("git clone https://github.com/olofk/serv")
+        vdir = os.path.join("serv", "rtl")
+        platform.add_source_dir(vdir)
+        platform.add_verilog_include_path(vdir)
+
+    def do_finalize(self):
+        assert hasattr(self, "reset_address")
+        self.specials += Instance("serv_top", **self.cpu_params)

diff --git a/litex/soc/integration/soc_core.py b/litex/soc/integration/soc_core.py
index 3eb0016c70560ec2d71809c154cb07b8ca3d617c..ab8704ced39065ffd0c56cb8ebccd17ce6bf8ae1 100644 (file)
--- a/litex/soc/integration/soc_core.py
+++ b/litex/soc/integration/soc_core.py
@@ -132,6 +132,9 @@ class SoCCore(LiteXSoC):
         self.cpu_type                   = cpu_type
         self.cpu_variant                = cpu_variant
 
+        if cpu_type == "serv":
+            self.add_constant("UART_POLLING") # FIXME: use UART in polling mode for SERV bringup
+
         self.integrated_rom_size        = integrated_rom_size
         self.integrated_rom_initialized = integrated_rom_init != []
         self.integrated_sram_size       = integrated_sram_size

diff --git a/litex/soc/software/bios/boot-helper-serv.S b/litex/soc/software/bios/boot-helper-serv.S
new file mode 100644 (file)
index 0000000..e8bd5c7
--- /dev/null
+++ b/litex/soc/software/bios/boot-helper-serv.S
@@ -0,0 +1,4 @@
+       .section .text, "ax", @progbits
+       .global boot_helper
+boot_helper:
+       jr x13

diff --git a/litex/soc/software/bios/main.c b/litex/soc/software/bios/main.c
index 0d2e6d863e8dfab1a1b94507baec8563b8078c38..1d68210c9a1edf4a3dfcf72b8bf0eca5c2967405 100644 (file)
--- a/litex/soc/software/bios/main.c
+++ b/litex/soc/software/bios/main.c
@@ -647,6 +647,8 @@ int main(int i, char **c)
        printf("RocketRV64[imac]");
 #elif __blackparrot__
         printf("BlackParrotRV64[ia]");
+#elif __serv__
+       printf("SERV");
 #else
        printf("Unknown");
 #endif

diff --git a/litex/soc/software/bios/sdram.c b/litex/soc/software/bios/sdram.c
index 53333cd84b1fe1cb6e52328cefca33041c12f39c..de49a942dddac2b882c84e3c8fe382cb3adea836 100644 (file)
--- a/litex/soc/software/bios/sdram.c
+++ b/litex/soc/software/bios/sdram.c
@@ -48,6 +48,8 @@ __attribute__((unused)) static void cdelay(int i)
                __asm__ volatile("nop");
 #elif defined (__blackparrot__)
                __asm__ volatile("nop");
+#elif defined (__serv__)
+               __asm__ volatile("nop");
 #else
 #error Unsupported architecture
 #endif

diff --git a/litex/soc/software/include/base/irq.h b/litex/soc/software/include/base/irq.h
index 7ff9b40338628d60ee2fd501648635b42b4db1d7..00dad8a2bcd6059d1ddc6219956971df17cfde4e 100644 (file)
--- a/litex/soc/software/include/base/irq.h
+++ b/litex/soc/software/include/base/irq.h
@@ -75,6 +75,8 @@ static inline unsigned int irq_getie(void)
        return 0; // FIXME
 #elif defined (__blackparrot__) 
        return (csrr(mstatus) & CSR_MSTATUS_MIE) != 0;//TODO
+#elif defined (__serv__)
+       return 0; /* FIXME */
 #else
 #error Unsupported architecture
 #endif
@@ -104,6 +106,8 @@ static inline void irq_setie(unsigned int ie)
        // FIXME
 #elif defined (__blackparrot__)
        if(ie) csrs(mstatus,CSR_MSTATUS_MIE); else csrc(mstatus,CSR_MSTATUS_MIE);//TODO:BP
+#elif defined (__serv__)
+       /* FIXME */
 #else
 #error Unsupported architecture
 #endif
@@ -135,6 +139,8 @@ static inline unsigned int irq_getmask(void)
        return 0; // FIXME
 #elif defined (__blackparrot__)
        //TODO:BP
+#elif defined (__serv__)
+       return 0; /* FIXME */
 #else
 #error Unsupported architecture
 #endif
@@ -160,6 +166,8 @@ static inline void irq_setmask(unsigned int mask)
        // FIXME
 #elif defined (__blackparrot__)
        //TODO:BP
+#elif defined (__serv__)
+       /* FIXME */
 #else
 #error Unsupported architecture
 #endif
@@ -189,6 +197,8 @@ static inline unsigned int irq_pending(void)
        return 0; // FIXME
 #elif defined (__blackparrot__)
        return csr_readl(PLIC_PENDING) >> 1;//TODO:BP
+#elif defined (__serv__)
+       return 0;/* FIXME */
 #else
 #error Unsupported architecture
 #endif

diff --git a/litex/soc/software/libbase/crt0-serv.S b/litex/soc/software/libbase/crt0-serv.S
new file mode 100644 (file)
index 0000000..6f6e9e6
--- /dev/null
+++ b/litex/soc/software/libbase/crt0-serv.S
@@ -0,0 +1,63 @@
+#define MIE_MEIE       0x800
+
+       .global _start
+_start:
+       j reset_vector
+
+reset_vector:
+       la sp, _fstack
+       la t0, trap_vector
+       csrw mtvec, t0
+
+       // initialize .bss
+       la t0, _fbss
+       la t1, _ebss
+1:     beq t0, t1, 2f
+       sw zero, 0(t0)
+       addi t0, t0, 4
+       j 1b
+2:
+       // 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

diff --git a/litex/soc/software/libbase/system.c b/litex/soc/software/libbase/system.c
index e8b3e50553ed067f397690f1b612eafc34febdc9..49d23ac6db696eb92679416e7d7132ba3f045cbc 100644 (file)
--- a/litex/soc/software/libbase/system.c
+++ b/litex/soc/software/libbase/system.c
@@ -62,6 +62,8 @@ void flush_cpu_icache(void)
 #elif defined (__blackparrot__)
        /* TODO: BP do something useful here! */
        asm volatile("nop");
+#elif defined (__serv__)
+       /* no instruction cache */
 #else
 #error Unsupported architecture
 #endif
@@ -114,6 +116,8 @@ void flush_cpu_dcache(void)
 #elif defined (__blackparrot__)
        /* FIXME: do something useful here! */
        asm volatile("nop");
+#elif defined (__serv__)
+       /* no data cache */
 #else
 #error Unsupported architecture
 #endif