Add CSR support to go_utils.py

go_utils.py now generates a Go map that maps CSR numbers to CSR
names. The resulting map is written into inst.go for use by the
Go assembler.

go_utils.py

@@ -3,6 +3,7 @@
 import subprocess
 import sys
 
+from constants import csrs
 from shared_utils import InstrDict, signed
 
 pp = pprint.PrettyPrinter(indent=2)
@@ -32,9 +33,14 @@ def make_go(instr_dict: InstrDict):
 	switch a {
 """
 
-    endoffile = """  }
+    csrs_map_str = """  }
 	return nil
 }
+
+var csrs = map[uint16]string {
+"""
+
+    endoffile = """}
 """
 
     instr_str = ""
@@ -49,8 +55,11 @@ def make_go(instr_dict: InstrDict):
         instr_str += f"""  case A{i.upper().replace("_","")}:
     return &inst{{ {hex(opcode)}, {hex(funct3)}, {hex(rs1)}, {hex(rs2)}, {signed(csr,12)}, {hex(funct7)} }}
 """
+    for num, name in sorted(csrs, key=lambda row: row[0]):
+        csrs_map_str += f'{hex(num)} : "{name.upper()}",\n'
 
     with open("inst.go", "w", encoding="utf-8") as file:
         file.write(prelude)
         file.write(instr_str)
+        file.write(csrs_map_str)
         file.write(endoffile)