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-rw-r--r--qtmips_machine/core.cpp95
-rw-r--r--qtmips_machine/core.h33
2 files changed, 108 insertions, 20 deletions
diff --git a/qtmips_machine/core.cpp b/qtmips_machine/core.cpp
index b75e31b..7a1e4ba 100644
--- a/qtmips_machine/core.cpp
+++ b/qtmips_machine/core.cpp
@@ -39,11 +39,13 @@
using namespace machine;
-Core::Core(Registers *regs, MemoryAccess *mem_program, MemoryAccess *mem_data) {
+Core::Core(Registers *regs, MemoryAccess *mem_program, MemoryAccess *mem_data) :
+ ex_handlers() {
cycle_c = 0;
this->regs = regs;
this->mem_program = mem_program;
this->mem_data = mem_data;
+ ex_default_handler = new StopExceptionHandler();
}
void Core::step() {
@@ -60,6 +62,43 @@ unsigned Core::cycles() {
return cycle_c;
}
+Registers *Core::get_regs() {
+ return regs;
+}
+
+MemoryAccess *Core::get_mem_data() {
+ return mem_data;
+}
+
+MemoryAccess *Core::get_mem_program() {
+ return mem_program;
+}
+
+void Core::register_exception_handler(ExceptionCause excause, ExceptionHandler *exhandler)
+{
+ if (excause == EXCAUSE_NONE ) {
+ if (ex_default_handler != nullptr)
+ delete ex_default_handler;
+ ex_default_handler = exhandler;
+ } else {
+ ExceptionHandler *old = ex_handlers.take(excause);
+ delete old;
+ ex_handlers.insert(excause, exhandler);
+ }
+}
+
+bool Core::handle_exception(Core *core, Registers *regs, ExceptionCause excause,
+ std::uint32_t inst_addr, std::uint32_t next_addr,
+ uint32_t mem_ref_addr)
+{
+ ExceptionHandler *exhandler = ex_handlers.value(excause);
+ if (exhandler != nullptr)
+ return exhandler->handle_exception(core, regs, excause, inst_addr, next_addr, mem_ref_addr);
+ if (ex_default_handler != nullptr)
+ return ex_default_handler->handle_exception(core, regs, excause, inst_addr, next_addr, mem_ref_addr);
+ return false;
+}
+
struct Core::dtFetch Core::fetch() {
std::uint32_t inst_addr = regs->read_pc();
Instruction inst(mem_program->read_word(inst_addr));
@@ -205,6 +244,7 @@ struct Core::dtExecute Core::execute(const struct dtDecode &dt) {
struct Core::dtMemory Core::memory(const struct dtExecute &dt) {
emit instruction_memory(dt.inst);
std::uint32_t towrite_val = dt.alu_val;
+ std::uint32_t mem_addr = dt.alu_val;
bool memread = dt.memread;
bool memwrite = dt.memwrite;
bool regwrite = dt.regwrite;
@@ -217,9 +257,9 @@ struct Core::dtMemory Core::memory(const struct dtExecute &dt) {
if (dt.memctl == AC_CACHE_OP)
mem_data->sync();
else if (memwrite)
- mem_data->write_ctl(dt.memctl, dt.alu_val, dt.val_rt);
+ mem_data->write_ctl(dt.memctl, mem_addr, dt.val_rt);
else if (memread)
- towrite_val = mem_data->read_ctl(dt.memctl, dt.alu_val);
+ towrite_val = mem_data->read_ctl(dt.memctl, mem_addr);
}
emit memory_alu_value(dt.alu_val);
@@ -231,14 +271,12 @@ struct Core::dtMemory Core::memory(const struct dtExecute &dt) {
emit memory_memwrite_value(memwrite);
emit memory_regw_num_value(dt.rwrite);
- if ((dt.excause == EXCAUSE_BREAK) || (dt.excause == EXCAUSE_SYSCALL))
- emit memory_break_reached();
-
return {
.inst = dt.inst,
.regwrite = regwrite,
.rwrite = dt.rwrite,
.towrite_val = towrite_val,
+ .mem_addr = mem_addr,
.inst_addr = dt.inst_addr,
.excause = dt.excause,
};
@@ -318,7 +356,6 @@ void Core::dtDecodeInit(struct dtDecode &dt) {
dt.immediate_val = 0;
dt.ff_rs = FORWARD_NONE;
dt.ff_rt = FORWARD_NONE;
- dt.inst_addr = 0;
dt.excause = EXCAUSE_NONE;
}
@@ -331,7 +368,6 @@ void Core::dtExecuteInit(struct dtExecute &dt) {
dt.val_rt = 0;
dt.rwrite = 0;
dt.alu_val = 0;
- dt.inst_addr = 0;
dt.excause = EXCAUSE_NONE;
}
@@ -340,7 +376,7 @@ void Core::dtMemoryInit(struct dtMemory &dt) {
dt.regwrite = false;
dt.rwrite = false;
dt.towrite_val = 0;
- dt.inst_addr = 0;
+ dt.mem_addr = 0;
dt.excause = EXCAUSE_NONE;
}
@@ -363,14 +399,6 @@ void CoreSingle::do_step() {
struct dtDecode d = decode(f);
struct dtExecute e = execute(d);
struct dtMemory m = memory(e);
-
- if (m.excause != EXCAUSE_NONE) {
- regs->pc_abs_jmp(m.inst_addr + 4);
- if (jmp_delay_decode != nullptr)
- dtDecodeInit(*jmp_delay_decode);
- return;
- }
-
writeback(m);
if (jmp_delay_decode != nullptr) {
@@ -378,11 +406,20 @@ void CoreSingle::do_step() {
*jmp_delay_decode = d; // Copy current decode
} else
handle_pc(d);
+
+ if (m.excause != EXCAUSE_NONE) {
+ if (jmp_delay_decode != nullptr)
+ dtDecodeInit(*jmp_delay_decode);
+ handle_exception(this, regs, m.excause, m.inst_addr, regs->read_pc(), m.mem_addr);
+ return;
+ }
}
void CoreSingle::do_reset() {
- if (jmp_delay_decode != nullptr)
+ if (jmp_delay_decode != nullptr) {
Core::dtDecodeInit(*jmp_delay_decode);
+ jmp_delay_decode->inst_addr = 0;
+ }
}
CorePipelined::CorePipelined(Registers *regs, MemoryAccess *mem_program, MemoryAccess *mem_data, enum MachineConfig::HazardUnit hazard_unit) : \
@@ -412,7 +449,8 @@ void CorePipelined::do_step() {
if (excpt_in_progress) {
dtFetchInit(dt_f);
if (dt_m.excause != EXCAUSE_NONE) {
- regs->pc_abs_jmp(dt_m.inst_addr + 4);
+ regs->pc_abs_jmp(dt_e.inst_addr);
+ handle_exception(this, regs, dt_m.excause, dt_m.inst_addr, dt_e.inst_addr, dt_m.mem_addr);
}
return;
}
@@ -517,7 +555,26 @@ void CorePipelined::do_step() {
void CorePipelined::do_reset() {
dtFetchInit(dt_f);
+ dt_f.inst_addr = 0;
dtDecodeInit(dt_d);
+ dt_d.inst_addr = 0;
dtExecuteInit(dt_e);
+ dt_e.inst_addr = 0;
dtMemoryInit(dt_m);
+ dt_m.inst_addr = 0;
}
+
+bool StopExceptionHandler::handle_exception(Core *core, Registers *regs,
+ ExceptionCause excause, std::uint32_t inst_addr, std::uint32_t next_addr,
+ std::uint32_t mem_ref_addr) {
+
+#if 0
+ printf("Exception cause %d instruction PC 0x%08lx next PC 0x%08lx registers PC 0x%08lx mem ref 0x%08lx\n",
+ excause, (unsigned long)inst_addr, (unsigned long)next_addr,
+ (unsigned long)regs->read_pc(), (unsigned long)mem_ref_addr);
+#else
+ (void)excause; (void)inst_addr; (void)next_addr; (void)mem_ref_addr;
+#endif
+ emit core->stop_on_exception_reached();
+ return true;
+};
diff --git a/qtmips_machine/core.h b/qtmips_machine/core.h
index d5ce4fb..a41d98b 100644
--- a/qtmips_machine/core.h
+++ b/qtmips_machine/core.h
@@ -46,6 +46,24 @@
namespace machine {
+class Core;
+
+class ExceptionHandler : public QObject {
+ Q_OBJECT
+public:
+ virtual bool handle_exception(Core *core, Registers *regs, ExceptionCause excause,
+ std::uint32_t inst_addr, std::uint32_t next_addr,
+ std::uint32_t mem_ref_addr) = 0;
+};
+
+class StopExceptionHandler : public ExceptionHandler {
+ Q_OBJECT
+public:
+ bool handle_exception(Core *core, Registers *regs, ExceptionCause excause,
+ std::uint32_t inst_addr, std::uint32_t next_addr,
+ std::uint32_t mem_ref_addr);
+};
+
class Core : public QObject {
Q_OBJECT
public:
@@ -56,6 +74,11 @@ public:
unsigned cycles(); // Returns number of executed cycles
+ Registers *get_regs();
+ MemoryAccess *get_mem_data();
+ MemoryAccess *get_mem_program();
+ void register_exception_handler(ExceptionCause excause, ExceptionHandler *exhandler);
+
enum ForwardFrom {
FORWARD_NONE = 0b00,
FORWARD_FROM_W = 0b01,
@@ -110,17 +133,24 @@ signals:
void memory_memwrite_value(std::uint32_t);
void memory_memread_value(std::uint32_t);
void memory_regw_num_value(std::uint32_t);
- void memory_break_reached();
void writeback_value(std::uint32_t);
void writeback_regw_value(std::uint32_t);
void writeback_regw_num_value(std::uint32_t);
+ void stop_on_exception_reached();
+
protected:
virtual void do_step() = 0;
virtual void do_reset() = 0;
+ bool handle_exception(Core *core, Registers *regs, ExceptionCause excause,
+ std::uint32_t inst_addr, std::uint32_t next_addr,
+ std::uint32_t mem_ref_addr);
+
Registers *regs;
MemoryAccess *mem_data, *mem_program;
+ QMap<ExceptionCause, ExceptionHandler *> ex_handlers;
+ ExceptionHandler *ex_default_handler;
struct dtFetch {
Instruction inst; // Loaded instruction
@@ -173,6 +203,7 @@ protected:
bool regwrite;
std::uint8_t rwrite;
std::uint32_t towrite_val;
+ std::uint32_t mem_addr; // Address used to access memory
uint32_t inst_addr; // Address of instruction
enum ExceptionCause excause;
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 20:30:40 +0000