Add lm32 "lite" variant, remove mult/div from "minimal" and update compiler flags accordingly.

litex/soc/cores/cpu/lm32/core.py

@@ -7,7 +7,7 @@ from litex.soc.interconnect import wishbone
 
 class LM32(Module):
     def __init__(self, platform, eba_reset, variant=None):
-        assert variant in (None, "minimal"), "Unsupported variant %s" % variant
+        assert variant in (None, "lite", "minimal"), "Unsupported variant %s" % variant
         self.reset = Signal()
         self.ibus = i = wishbone.Interface()
         self.dbus = d = wishbone.Interface()
@@ -84,5 +84,7 @@ class LM32(Module):
                 "lm32_dtlb.v")
         if variant == "minimal":
             platform.add_verilog_include_path(os.path.join(vdir, "config_minimal"))
+        elif variant == "lite":
+            platform.add_verilog_include_path(os.path.join(vdir, "config_lite"))
         else:
             platform.add_verilog_include_path(os.path.join(vdir, "config"))

litex/soc/cores/cpu/lm32/verilog/config_lite/lm32_config.v

@@ -0,0 +1,199 @@
+`ifdef LM32_CONFIG_V
+`else
+`define LM32_CONFIG_V
+
+//
+// EXCEPTION VECTORS BASE ADDRESS
+//
+
+// Base address for exception vectors
+`define CFG_EBA_RESET 32'h00000000
+
+// Base address for the debug exception vectors. If the DC_RE flag is
+// set or the at_debug signal is asserted (see CFG_ALTERNATE_EBA) this
+// will also be used for normal exception vectors.
+`define CFG_DEBA_RESET 32'h10000000
+
+// Enable exception vector remapping by external signal
+//`define CFG_ALTERNATE_EBA
+
+
+//
+// ALU OPTIONS
+//
+
+// Enable sign-extension instructions
+`define CFG_SIGN_EXTEND_ENABLED
+
+// Shifter
+// You may either enable the piplined or the multi-cycle barrel
+// shifter. The multi-cycle shifter will stall the pipeline until
+// the result is available after 32 cycles.
+// If both options are disabled, only "right shift by one bit" is
+// available.
+`define CFG_MC_BARREL_SHIFT_ENABLED
+//`define CFG_PL_BARREL_SHIFT_ENABLED
+
+// Multiplier
+// The multiplier is available either in a multi-cycle version or
+// in a pipelined one. The multi-cycle multiplier stalls the pipe
+// for 32 cycles. If both options are disabled, multiply operations
+// are not supported.
+`define CFG_MC_MULTIPLY_ENABLED
+//`define CFG_PL_MULTIPLY_ENABLED
+
+// Enable the multi-cycle divider. Stalls the pipe until the result
+// is ready after 32 cycles. If disabled, the divide operation is not
+// supported.
+`define CFG_MC_DIVIDE_ENABLED
+
+
+//
+// INTERRUPTS
+//
+
+// Enable support for 32 hardware interrupts
+`define CFG_INTERRUPTS_ENABLED
+
+// Enable level-sensitive interrupts. The interrupt line status is
+// reflected in the IP register, which is then read-only.
+`define CFG_LEVEL_SENSITIVE_INTERRUPTS
+
+
+//
+// USER INSTRUCTION
+//
+
+// Enable support for the user opcode.
+//`define CFG_USER_ENABLED
+
+
+//
+// MEMORY MANAGEMENT UNIT
+//
+
+// Enable instruction and data translation lookaside buffers and
+// restricted user mode.
+//`define CFG_MMU_ENABLED
+
+
+//
+// CACHE
+//
+
+// Instruction cache
+`define CFG_ICACHE_ENABLED
+`define CFG_ICACHE_ASSOCIATIVITY   1
+`define CFG_ICACHE_SETS            128
+`define CFG_ICACHE_BYTES_PER_LINE  16
+`define CFG_ICACHE_BASE_ADDRESS    32'h00000000
+`define CFG_ICACHE_LIMIT           32'h7fffffff
+
+// Data cache
+//`define CFG_DCACHE_ENABLED
+`define CFG_DCACHE_ASSOCIATIVITY   1
+`define CFG_DCACHE_SETS            256
+`define CFG_DCACHE_BYTES_PER_LINE  16
+`define CFG_DCACHE_BASE_ADDRESS    32'h00000000
+`define CFG_DCACHE_LIMIT           32'h7fffffff
+
+
+//
+// DEBUG OPTION
+//
+
+// Globally enable debugging
+//`define CFG_DEBUG_ENABLED
+
+// Enable the hardware JTAG debugging interface.
+// Note: to use this, there must be a special JTAG module for your
+//       device. At the moment, there is only support for the
+//       Spartan-6.
+//`define CFG_JTAG_ENABLED
+
+// JTAG UART is a communication channel which uses JTAG to transmit
+// and receive bytes to and from the host computer.
+//`define CFG_JTAG_UART_ENABLED
+
+// Enable reading and writing to the memory and writing CSRs using
+// the JTAG interface.
+//`define CFG_HW_DEBUG_ENABLED
+
+// Number of hardware watchpoints, max. 4
+//`define CFG_WATCHPOINTS 32'h4
+
+// Enable hardware breakpoints
+//`define CFG_ROM_DEBUG_ENABLED
+
+// Number of hardware breakpoints, max. 4
+//`define CFG_BREAKPOINTS 32'h4
+
+// Put the processor into debug mode by an external signal. That is,
+// raise a breakpoint exception. This is useful if you have a debug
+// monitor and a serial line and you want to trap into the monitor on a
+// BREAK symbol on the serial line.
+//`define CFG_EXTERNAL_BREAK_ENABLED
+
+
+//
+// REGISTER FILE
+//
+
+// The following option explicitly infers block RAM for the register
+// file. There is extra logic to avoid parallel writes and reads.
+// Normally, if your synthesizer is smart enough, this should not be
+// necessary because it will automatically infer block RAM for you.
+//`define CFG_EBR_POSEDGE_REGISTER_FILE
+
+// Explicitly infers block RAM, too. But it uses two different clocks,
+// one being shifted by 180deg, for the read and write port. Therefore,
+// no additional logic to avoid the parallel write/reads.
+//`define CFG_EBR_NEGEDGE_REGISTER_FILE
+
+
+//
+// MISCELLANEOUS
+//
+
+// Exceptions on wishbone bus errors
+//`define CFG_BUS_ERRORS_ENABLED
+
+// Enable the cycle counter
+`define CFG_CYCLE_COUNTER_ENABLED
+
+// Embedded instruction ROM using on-chip block RAM
+//`define CFG_IROM_ENABLED
+//`define CFG_IROM_INIT_FILE     "NONE"
+//`define CFG_IROM_BASE_ADDRESS  32'h10000000
+//`define CFG_IROM_LIMIT         32'h10000fff
+
+// Embedded data RAM using on-chip block RAM
+//`define CFG_DRAM_ENABLED
+//`define CFG_DRAM_INIT_FILE     "NONE"
+//`define CFG_DRAM_BASE_ADDRESS  32'h20000000
+//`define CFG_DRAM_LIMIT         32'h20000fff
+
+// Trace unit
+//`define CFG_TRACE_ENABLED
+
+// Resolve unconditional branches already in the X stage (UNTESTED!)
+//`define CFG_FAST_UNCONDITIONAL_BRANCH
+
+// log2 function
+// If your simulator/synthesizer does not support the $clog2 system
+// function you can use a constant function instead.
+
+function integer clog2;
+  input integer value;
+  begin
+    value = value - 1;
+    for (clog2 = 0; value > 0; clog2 = clog2 + 1)
+      value = value >> 1;
+  end
+endfunction
+
+`define CLOG2 clog2
+
+//`define CLOG2 $clog2
+
+`endif

litex/soc/cores/cpu/lm32/verilog/config_minimal/lm32_config.v

@@ -39,13 +39,13 @@
 // in a pipelined one. The multi-cycle multiplier stalls the pipe
 // for 32 cycles. If both options are disabled, multiply operations
 // are not supported.
-`define CFG_MC_MULTIPLY_ENABLED
+//`define CFG_MC_MULTIPLY_ENABLED
 //`define CFG_PL_MULTIPLY_ENABLED
 
 // Enable the multi-cycle divider. Stalls the pipe until the result
 // is ready after 32 cycles. If disabled, the divide operation is not
 // supported.
-`define CFG_MC_DIVIDE_ENABLED
+//`define CFG_MC_DIVIDE_ENABLED
 
 
 //

litex/soc/integration/builder.py

@@ -56,6 +56,7 @@ class Builder:
 
     def _generate_includes(self):
         cpu_type = self.soc.cpu_type
+        cpu_variant = self.soc.cpu_variant
         memory_regions = self.soc.get_memory_regions()
         flash_boot_address = getattr(self.soc, "flash_boot_address", None)
         csr_regions = self.soc.get_csr_regions()
@@ -68,7 +69,7 @@ class Builder:
         variables_contents = []
         def define(k, v):
             variables_contents.append("{}={}\n".format(k, _makefile_escape(v)))
-        for k, v in cpu_interface.get_cpu_mak(cpu_type):
+        for k, v in cpu_interface.get_cpu_mak(cpu_type, cpu_variant):
             define(k, v)
         define("SOC_DIRECTORY", soc_directory)
         variables_contents.append("export BUILDINC_DIRECTORY\n")

litex/soc/integration/cpu_interface.py

@@ -13,7 +13,7 @@ cpu_endianness = {
     "vexriscv": "little"
 }
 
-def get_cpu_mak(cpu):
+def get_cpu_mak(cpu, variant):
     clang = os.getenv("CLANG", "")
     if clang != "":
         clang = bool(int(clang))
@@ -23,6 +23,9 @@ def get_cpu_mak(cpu):
     if cpu == "lm32":
         assert not clang, "lm32 not supported with clang."
         triple = "lm32-elf"
+        if variant == "minimal":
+            cpuflags = "-mbarrel-shift-enabled -msign-extend-enabled"
+        else:
             cpuflags = "-mbarrel-shift-enabled -mmultiply-enabled -mdivide-enabled -msign-extend-enabled"
         clang = False
     elif cpu == "or1k":

litex/soc/software/libcompiler_rt/Makefile

@@ -15,7 +15,7 @@ all: libcompiler_rt.a
 
 libcompiler_rt.a: $(OBJECTS)
 	$(CC) -c $(CFLAGS) $(1) $(SOC_DIRECTORY)/software/libcompiler_rt/mulsi3.c -o mulsi3.o
-	$(AR) crs libcompiler_rt.a $(OBJECTS)
+	$(AR) crs libcompiler_rt.a $(OBJECTS) mulsi3.o
 
 # pull in dependency info for *existing* .o files
 -include $(OBJECTS:.o=.d)