diff --git a/cpu/ppc/ppcexec.cpp b/cpu/ppc/ppcexec.cpp
index 2278f08..1f88064 100644
--- a/cpu/ppc/ppcexec.cpp
+++ b/cpu/ppc/ppcexec.cpp
@@ -33,6 +33,8 @@ along with this program. If not, see .
#include "ppcemu.h"
#include "ppcmmu.h"
+#define NEW_TBR_UPDATE_ALGO
+
using namespace std;
MemCtrlBase *mem_ctrl_instance = 0;
@@ -52,7 +54,13 @@ uint32_t ppc_next_instruction_address; //Used for branching, setting up the NIA
BB_end_kind bb_kind; /* basic block end */
-uint64_t timebase_counter; /* internal timebase counter */
+/* variables related to virtual time */
+uint64_t cycles_count; /* contains number of cycles executed so far */
+uint64_t old_cycles_count; /* previous value for cycles_count */
+uint64_t timebase_counter; /* internal timebase counter */
+uint32_t decr; /* current value of PPC DEC register */
+uint8_t old_decr_msb; /* MSB value for previous DEC value */
+uint8_t tbr_factor; /* cycles_count to TBR freq ratio in 2^x units */
clock_t clock_test_begin; //Used to make sure the TBR does not increment so quickly.
@@ -426,6 +434,18 @@ static std::unordered_map SubOpcode63Grabber = {
{2045, &ppc_fnmsubdot}, {2046, &ppc_fnmadd}, {2047, &ppc_fnmadddot}
};
+
+#define UPDATE_TBR_DEC \
+ if ((delta = (cycles_count - old_cycles_count) >> tbr_factor)) { \
+ timebase_counter += delta; \
+ decr -= delta; \
+ if ((decr & 0x80000000) && !old_decr_msb) { \
+ old_decr_msb = decr >> 31; \
+ /* signal_decr_int(); */ \
+ } \
+ old_cycles_count += delta << tbr_factor; \
+ }
+
/** Opcode decoding functions. */
void ppc_illegalop() {
@@ -532,61 +552,11 @@ void ppc_main_opcode() {
OpcodeGrabber[ppc_mainop]();
}
-/** Old time base register (TBR) update code. */
-void tbr_update()
-{
- clock_t clock_test_current = clock();
- uint32_t test_clock = ((uint32_t)(clock_test_current - clock_test_begin)) / CLOCKS_PER_SEC;
- if (test_clock) {
- if (ppc_state.tbr[0] != 0xFFFFFFFF) {
- ppc_state.tbr[0]++;
- }
- else {
- ppc_state.tbr[0] = 0;
- if (ppc_state.tbr[1] != 0xFFFFFFFF) {
- ppc_state.tbr[1]++;
- }
- else {
- ppc_state.tbr[1] = 0;
- }
- }
- clock_test_begin = clock();
- //Placeholder Decrementing Code
- if (ppc_state.spr[22] > 0) {
- ppc_state.spr[22]--;
- }
- }
-}
/** Execute PPC code as long as power is on. */
-#if 0
void ppc_exec()
{
- while (power_on) {
- //printf("PowerPC Address: %x \n", ppc_state.pc);
- quickinstruction_translate(ppc_state.pc);
- ppc_main_opcode();
- if (grab_branch & !grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_branch = 0;
- tbr_update();
- }
- else if (grab_return | grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_exception = 0;
- grab_return = 0;
- tbr_update();
- }
- else {
- ppc_state.pc += 4;
- tbr_update();
- }
- }
-}
-#else
-void ppc_exec()
-{
- uint32_t bb_start_la, page_start;
+ uint32_t bb_start_la, page_start, delta;
uint8_t* pc_real;
/* start new basic block */
@@ -595,7 +565,12 @@ void ppc_exec()
if (setjmp(exc_env)) {
/* reaching here means we got a low-level exception */
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count += ((ppc_state.pc - bb_start_la) >> 2) + 1;
+ UPDATE_TBR_DEC
+#else
timebase_counter += (ppc_state.pc - bb_start_la) >> 2;
+#endif
bb_start_la = ppc_next_instruction_address;
pc_real = quickinstruction_translate(bb_start_la);
page_start = bb_start_la & 0xFFFFF000;
@@ -614,7 +589,12 @@ again:
while (power_on) {
ppc_main_opcode();
if (bb_kind != BB_end_kind::BB_NONE) {
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count += ((ppc_state.pc - bb_start_la) >> 2) + 1;
+ UPDATE_TBR_DEC
+#else
timebase_counter += (ppc_state.pc - bb_start_la) >> 2;
+#endif
bb_start_la = ppc_next_instruction_address;
if ((ppc_next_instruction_address & 0xFFFFF000) != page_start) {
page_start = bb_start_la & 0xFFFFF000;
@@ -634,36 +614,20 @@ again:
}
}
}
-#endif
/** Execute one PPC instruction. */
-#if 0
-void ppc_exec_single()
-{
- quickinstruction_translate(ppc_state.pc);
- ppc_main_opcode();
- if (grab_branch && !grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_branch = 0;
- tbr_update();
- }
- else if (grab_return || grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_exception = 0;
- grab_return = 0;
- tbr_update();
- }
- else {
- ppc_state.pc += 4;
- tbr_update();
- }
-}
-#else
void ppc_exec_single()
{
+ uint32_t delta;
+
if (setjmp(exc_env)) {
/* reaching here means we got a low-level exception */
- timebase_counter += 1;
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count++;
+ UPDATE_TBR_DEC
+#else
+ timebase_counter++;
+#endif
ppc_state.pc = ppc_next_instruction_address;
bb_kind = BB_end_kind::BB_NONE;
return;
@@ -678,39 +642,18 @@ void ppc_exec_single()
else {
ppc_state.pc += 4;
}
- timebase_counter += 1;
-}
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count++;
+ UPDATE_TBR_DEC
+#else
+ timebase_counter++;
#endif
+}
/** Execute PPC code until goal_addr is reached. */
-#if 0
void ppc_exec_until(uint32_t goal_addr)
{
- while (ppc_state.pc != goal_addr) {
- quickinstruction_translate(ppc_state.pc);
- ppc_main_opcode();
- if (grab_branch && !grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_branch = 0;
- tbr_update();
- }
- else if (grab_return || grab_exception) {
- ppc_state.pc = ppc_next_instruction_address;
- grab_exception = 0;
- grab_return = 0;
- tbr_update();
- }
- else {
- ppc_state.pc += 4;
- tbr_update();
- }
- ppc_cur_instruction = 0;
- }
-}
-#else
-void ppc_exec_until(uint32_t goal_addr)
-{
- uint32_t bb_start_la, page_start;
+ uint32_t bb_start_la, page_start, delta;
uint8_t* pc_real;
/* start new basic block */
@@ -719,7 +662,12 @@ void ppc_exec_until(uint32_t goal_addr)
if (setjmp(exc_env)) {
/* reaching here means we got a low-level exception */
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count += ((ppc_state.pc - bb_start_la) >> 2) + 1;
+ UPDATE_TBR_DEC
+#else
timebase_counter += (ppc_state.pc - bb_start_la) >> 2;
+#endif
bb_start_la = ppc_next_instruction_address;
pc_real = quickinstruction_translate(bb_start_la);
page_start = bb_start_la & 0xFFFFF000;
@@ -738,7 +686,12 @@ again:
while (ppc_state.pc != goal_addr) {
ppc_main_opcode();
if (bb_kind != BB_end_kind::BB_NONE) {
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count += ((ppc_state.pc - bb_start_la) >> 2) + 1;
+ UPDATE_TBR_DEC
+#else
timebase_counter += (ppc_state.pc - bb_start_la) >> 2;
+#endif
bb_start_la = ppc_next_instruction_address;
if ((ppc_next_instruction_address & 0xFFFFF000) != page_start) {
page_start = bb_start_la & 0xFFFFF000;
@@ -758,7 +711,41 @@ again:
}
}
}
-#endif
+
+
+uint64_t instr_count, old_instr_count;
+
+void test_timebase_update()
+{
+ uint32_t delta, factor;
+ uint8_t old_decr_msb;
+ uint8_t intervals[10] = {4, 7, 10, 2, 16, 6, 3, 20, 12, 8};
+
+ timebase_counter = 0;
+ decr = 0x00000003;
+ old_decr_msb = decr >> 31;
+
+ old_instr_count = 0xFFFFFFFFFFFFFF80UL;//0xFFFFFFFFFFFFFFD0UL;
+ instr_count = 0xFFFFFFFFFFFFFF80UL;//0xFFFFFFFFFFFFFFD0UL;
+
+ factor = 4;
+
+ for (int i = 0; i < 10; i++) {
+ cycles_count += intervals[i];
+ if ((delta = (cycles_count - old_cycles_count) >> factor)) {
+ timebase_counter += delta;
+ decr -= delta;
+ if ((decr & 0x80000000) && !old_decr_msb) {
+ old_decr_msb = decr >> 31;
+ LOG_F(ERROR, "DEC exception signaled!\n");
+ }
+ old_instr_count += delta << factor;
+ LOG_F(INFO, "Iteration %d, TBR=0x%llX, DEC=0x%X", i, timebase_counter, decr);
+ LOG_F(INFO, " icount=0x%llX, old_icount=0x%llX\n", cycles_count, old_cycles_count);
+ }
+ }
+
+}
void ppc_cpu_init(MemCtrlBase *mem_ctrl, uint32_t proc_version)
{
@@ -766,8 +753,18 @@ void ppc_cpu_init(MemCtrlBase *mem_ctrl, uint32_t proc_version)
mem_ctrl_instance = mem_ctrl;
- clock_test_begin = clock();
+ //test_timebase_update();
+
+ /* initialize timer variables */
+#ifdef NEW_TBR_UPDATE_ALGO
+ cycles_count = 0;
+ old_cycles_count = 0;
+ tbr_factor = 4;
+#endif
+
timebase_counter = 0;
+ decr = 0;
+ old_decr_msb = decr >> 31;
/* zero all GPRs as prescribed for MPC601 */
/* For later PPC CPUs, GPR content is undefined */