Use blackbox to rebuild AXI-flash (#726)

* AXIFlash: use blackbox to rebuild flash

* device.cpp: add init_flash

* Add flash.cpp for DPI-C funtion

* Flash: use USE_BIN to enable FI from flash

* AXIFlash: delete original flash

Makefile

@@ -107,6 +107,11 @@ ifeq ($(DUALCORE),1)
 EMU_CXXFLAGS += -DDUALCORE
 endif
 
+USE_BIN ?= 0
+ifeq ($(USE_BIN),1)
+EMU_CXXFLAGS += -DUSE_BIN
+endif
+
 # --trace
 VERILATOR_FLAGS = --top-module $(EMU_TOP) \
   +define+VERILATOR=1 \

src/main/scala/device/AXI4Flash.scala

@@ -6,6 +6,38 @@ import chipsalliance.rocketchip.config.Parameters
 import freechips.rocketchip.diplomacy.AddressSet
 import utils._
 
+class FlashHelper extends BlackBox with HasBlackBoxInline {
+  val io = IO(new Bundle {
+    val clk = Input(Clock())
+    val ren = Input(Bool())
+    val data = Output(UInt(64.W))
+    val addr = Input(UInt(32.W))
+  })
+
+  setInline("FlashHelper.v",
+    s"""
+       |import "DPI-C" function void flash_read
+       |(  
+       |  input int addr,
+       |  output longint data
+       |);
+       |
+       |module FlashHelper (
+       |  input clk,
+       |  input [31:0] addr,
+       |  input ren,
+       |  output reg [63:0] data
+       |);
+       |
+       |  always @(posedge clk) begin
+       |    if (ren) flash_read(addr, data);
+       |  end
+       |
+       |endmodule
+     """.stripMargin)
+}
+
+
 class AXI4Flash
 (
   address: Seq[AddressSet]
@@ -14,23 +46,13 @@ class AXI4Flash
 {
 
   override lazy val module = new AXI4SlaveModuleImp(this){
-    val jmpToDramInstr1 = "h0010029b".U  // addiw t0,zero,1
-    val jmpToDramInstr2 = "h01f29293".U  // slli  t0,t0,0x1f
-    val jmpToDramInstr3 = "h00028067".U  // jr t0
-
-    val mapping = Map(
-      RegMap(0x0, jmpToDramInstr1, RegMap.Unwritable),
-      RegMap(0x4, jmpToDramInstr2, RegMap.Unwritable),
-      RegMap(0x8, jmpToDramInstr3, RegMap.Unwritable)
-    )
-    def getOffset(addr: UInt) = addr(12,0)
-
-    val rdata = Wire(Vec(2,UInt(32.W)))
-    (0 until 2).map{ i =>
-      RegMap.generate(mapping, getOffset(raddr + (i * 4).U), rdata(i),
-        getOffset(waddr), in.w.fire(), in.w.bits.data, MaskExpand(in.w.bits.strb))
-    }
-
-    in.r.bits.data := rdata.asUInt
+    def getOffset(addr: UInt) = addr(15,0)
+
+    val flash = Module(new FlashHelper)
+    flash.io.clk := clock
+    flash.io.ren := in.ar.fire()
+    flash.io.addr := Cat(0.U(16.W), getOffset(raddr))
+
+    in.r.bits.data := flash.io.data
   }
 }

src/test/csrc/device.cpp

@@ -7,6 +7,7 @@ void init_sdl(void);
 
 void init_uart(void);
 extern "C" void init_sd(void);
+extern "C" void init_flash(void);
 
 static struct timeval boot = {};
 
@@ -14,6 +15,7 @@ void init_device(void) {
   init_sdl();
   init_uart();
   init_sd();
+  init_flash();
   gettimeofday(&boot, NULL);
 }
 

src/test/csrc/difftest.cpp

@@ -51,7 +51,11 @@ void init_difftest() {
   }
 
   for (int i = 0; i < NumCore; i++) {
-    nemu_this_pc[i] = 0x80000000;
+#ifdef USE_BIN
+      nemu_this_pc[i] = 0x10000000;
+#else
+      nemu_this_pc[i] = 0x80000000;
+#endif 
     pc_retire_pointer[i] = DEBUG_RETIRE_TRACE_SIZE-1;
   }
 }

src/test/csrc/emu.cpp

@@ -611,12 +611,22 @@ uint64_t Emulator::execute(uint64_t max_cycle, uint64_t max_instr) {
     }
 
     for (int i = 0; i < NumCore; i++) {
+#ifdef USE_BIN
+#ifdef DUALCORE
+      int first_instr_commit = (i == 0) ? dut_ptr->io_difftest_commit && dut_ptr->io_difftest_thisPC == 0x10000000u :
+                                          dut_ptr->io_difftest2_commit && dut_ptr->io_difftest2_thisPC == 0x10000000u;
+#else
+      int first_instr_commit = dut_ptr->io_difftest_commit && dut_ptr->io_difftest_thisPC == 0x10000000u;
+#endif
+#else 
 #ifdef DUALCORE
       int first_instr_commit = (i == 0) ? dut_ptr->io_difftest_commit && dut_ptr->io_difftest_thisPC == 0x80000000u :
                                           dut_ptr->io_difftest2_commit && dut_ptr->io_difftest2_thisPC == 0x80000000u;
 #else
       int first_instr_commit = dut_ptr->io_difftest_commit && dut_ptr->io_difftest_thisPC == 0x80000000u;
+#endif  
 #endif
+
       if (!hascommit[i] && first_instr_commit) {
         hascommit[i] = 1;
 #ifdef DUALCORE

src/test/csrc/flash.cpp

+#include "common.h"
+#include "flash.h"
+
+FILE *flash_fp = NULL;
+
+extern "C" {
+
+void flash_read(uint32_t addr, uint64_t *data) {
+#ifdef USE_BIN
+  fseek(flash_fp, addr, SEEK_SET);
+  fread(data, 8, 1, flash_fp);
+#else
+  uint32_t index = addr & 0x00000fff;
+  switch(index>>3){
+    case 0 :
+      *data = 0x01f292930010029b;
+      break;
+    case 1 :
+      *data = 0x00028067;
+      break;
+    default :
+      *data = 0;
+  }
+#endif
+}
+
+void init_flash(void) {
+#ifdef USE_BIN
+
+  flash_fp = fopen("/home/jy/Project/nexus-am/tests/cputest/build/dummy-riscv64-noop.bin", "r");
+  if(!flash_fp)
+  {
+    eprintf(ANSI_COLOR_MAGENTA "[warning] flash img not found\n");
+  }
+  printf("use bin as a flash!\n"); 
+#else 
+  printf("use fixed 3 instructions!\n");
+#endif
+}
+
+}

src/test/csrc/flash.h

+#ifndef __FLASH_H
+#define __FLASH_H
+
+#include "common.h"
+
+#endif // __FLASH_H