feat(diff): support Sstc extension and set csr init (#55)

* feat(diff): support Sstc extension

* fix(csr): set xtimecmp and m/henvcfg init when Sstc extension enable

Author: sinceforYy

difftest/difftest-def.h

@@ -80,7 +80,8 @@
     "_zfa_zfh_zvfh" \
     "_svinval_sscofpmf" \
     "_svpbmt" \
-    "_zicbom_zicboz"
+    "_zicbom_zicboz" \
+    "_sstc"
 
 #define CONFIG_MEMORY_SIZE     (16 * 1024 * 1024 * 1024UL)
 #define CONFIG_FLASH_BASE      0x10000000UL

riscv/csr_init.cc

@@ -271,7 +271,8 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
                             (proc->extension_enabled(EXT_ZICFISS) ? MENVCFG_SSE : 0) |
                             (proc->extension_enabled(EXT_SSDBLTRP) ? MENVCFG_DTE : 0);
   const reg_t menvcfg_init = (proc->extension_enabled(EXT_ZICBOM) ? MENVCFG_CBCFE | MENVCFG_CBIE : 0) |
-                              (proc->extension_enabled(EXT_ZICBOZ) ? MENVCFG_CBZE : 0);
+                              (proc->extension_enabled(EXT_ZICBOZ) ? MENVCFG_CBZE : 0) |
+                              (proc->extension_enabled(EXT_SSTC) ? MENVCFG_STCE : 0);
   menvcfg = std::make_shared<envcfg_csr_t>(proc, CSR_MENVCFG, menvcfg_mask, menvcfg_init);
   if (xlen == 32) {
     add_user_csr(CSR_MENVCFG, std::make_shared<rv32_low_csr_t>(proc, CSR_MENVCFG, menvcfg));
@@ -298,7 +299,8 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
                             (proc->extension_enabled(EXT_ZICFISS) ? HENVCFG_SSE : 0) |
                             (proc->extension_enabled(EXT_SSDBLTRP) ? HENVCFG_DTE : 0);
   const reg_t henvcfg_init = (proc->extension_enabled(EXT_ZICBOM) ? HENVCFG_CBCFE | HENVCFG_CBIE : 0) |
-                              (proc->extension_enabled(EXT_ZICBOZ) ? HENVCFG_CBZE : 0);
+                              (proc->extension_enabled(EXT_ZICBOZ) ? HENVCFG_CBZE : 0) |
+                              (proc->extension_enabled(EXT_SSTC) ? HENVCFG_STCE : 0);
   henvcfg = std::make_shared<henvcfg_csr_t>(proc, CSR_HENVCFG, henvcfg_mask, henvcfg_init, menvcfg);
   if (xlen == 32) {
     add_hypervisor_csr(CSR_HENVCFG, std::make_shared<rv32_low_csr_t>(proc, CSR_HENVCFG, henvcfg));

riscv/csrs.cc

@@ -1740,7 +1740,7 @@ bool henvcfg_csr_t::unlogged_write(const reg_t val) noexcept {
 }
 
 stimecmp_csr_t::stimecmp_csr_t(processor_t* const proc, const reg_t addr, const reg_t imask):
-  basic_csr_t(proc, addr, 0), intr_mask(imask) {
+  basic_csr_t(proc, addr, 0xffffffffffffffff), intr_mask(imask) {
 }
 
 bool stimecmp_csr_t::unlogged_write(const reg_t val) noexcept {