Merge branch 'riscv64-difftest-csr' into 'rv64'

riscv64,difftest: add [m|s][status|cause|epc]

See merge request projectn/nemu!30

src/isa/riscv64/diff-test.c

 #include "nemu.h"
 #include "monitor/diff-test.h"
+#include "csr.h"
 
 bool isa_difftest_checkregs(CPU_state *ref_r, vaddr_t pc) {
   if (memcmp(&cpu, ref_r, DIFFTEST_REG_SIZE)) {
@@ -17,3 +18,24 @@ void isa_difftest_attach(void) {
   ref_difftest_memcpy_from_dut(0, guest_to_host(0), PMEM_SIZE);
   ref_difftest_setregs(&cpu);
 }
+
+void isa_difftest_getregs_hook(void) {
+  cpu.mstatus = mstatus->val;
+  cpu.mcause  = mcause->val;
+  cpu.mepc    = mepc->val;
+
+  rtlreg_t temp;
+  csr_read(&temp, 0x100); // sstatus
+  cpu.sstatus = temp;
+  cpu.scause  = scause->val;
+  cpu.sepc    = sepc->val;
+}
+
+void isa_difftest_setregs_hook(void) {
+  mstatus->val = cpu.mstatus;
+  mcause ->val = cpu.mcause ;
+  mepc   ->val = cpu.mepc   ;
+  //sstatus->val = cpu.sstatus;  // sstatus is a shadow of mstatus
+  scause ->val = cpu.scause ;
+  sepc   ->val = cpu.sepc   ;
+}

src/isa/riscv64/include/isa/diff-test.h

 #ifndef __RISCV64_DIFF_TEST_H__
 #define __RISCV64_DIFF_TEST_H__
 
-#define DIFFTEST_REG_SIZE (sizeof(uint64_t) * 33) // GRPs + pc
+#define DIFFTEST_REG_SIZE (sizeof(uint64_t) * (32 + 1 + 6)) // GRPs + pc + [m|s][status|cause|epc]
+
+void isa_difftest_getregs_hook(void);
+void isa_difftest_setregs_hook(void);
 
 #endif

src/isa/riscv64/include/isa/reg.h

@@ -15,6 +15,9 @@ typedef struct {
   } gpr[32];
 
   vaddr_t pc;
+  vaddr_t mstatus, mcause, mepc;
+  vaddr_t sstatus, scause, sepc;
+
   uint8_t mode;
 
   bool fetching;

src/monitor/diff-test/ref.c

@@ -10,11 +10,13 @@ void difftest_memcpy_from_dut(paddr_t dest, void *src, size_t n) {
 }
 
 void difftest_getregs(void *r) {
+  isa_difftest_getregs_hook();
   memcpy(r, &cpu, DIFFTEST_REG_SIZE);
 }
 
 void difftest_setregs(const void *r) {
   memcpy(&cpu, r, DIFFTEST_REG_SIZE);
+  isa_difftest_setregs_hook();
 }
 
 void difftest_exec(uint64_t n) {