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Change workaround for the dynamic core #5718

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f7f9344
Revert "CPU reset workaround that allows system reset to work properl…
henk717 May 4, 2025
702887f
Dynamic core rebootlanguage workaround
henk717 May 21, 2025
4a7e2fc
Merge branch 'joncampbell123:master' into master
henk717 May 21, 2025
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30 changes: 0 additions & 30 deletions src/cpu/cpu.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3196,36 +3196,6 @@ bool CPU_CPUID(void) {
return true;
}

/* this is used by dynamic core as a workaround for sending the reset signal into the emulator
* because C++ exceptions don't work from within dynamically generated code. */
int reset_decode_signal = 0;
Bits Reset_Decode(void) {
LOG_MSG("CPU: It is now safe to send reset signal");
cpudecoder = cpu.hlt.old_decoder;
throw int(reset_decode_signal);
return 0;
}

void CPU_SetResetSignal(int x) {
LOG_MSG("CPU: Queuing reset signal, to send when dynamic core has completed execution.");
reset_decode_signal = x;
cpu.hlt.old_decoder = cpudecoder;
cpudecoder = &Reset_Decode;
CPU_Cycles = 0;
}

bool CPU_DynamicCoreCannotUseCPPExceptions(void) {
#if C_DYNAMIC_X86
if (cpudecoder == &CPU_Core_Dyn_X86_Run)
return true;
#endif
#if C_DYNREC
if (cpudecoder == &CPU_Core_Dynrec_Run)
return true;
#endif
return false;
}

Bits HLT_Decode(void) {
/* Once an interrupt occurs, it should change cpu core */
if (reg_eip!=cpu.hlt.eip || SegValue(cs) != cpu.hlt.cs) {
Expand Down
58 changes: 26 additions & 32 deletions src/hardware/memory.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,8 @@
#include "../gamelink/gamelink.h"
#endif // C_GAMELINK

void RebootLanguage(std::string filename, bool confirm=false);

/* memory from file, memory mapping */
#if C_HAVE_MMAP
# define DO_MEMORY_FILE
Expand Down Expand Up @@ -196,7 +198,7 @@ class MEM_callout_vector : public std::vector<MEM_CalloutObject> {

static MEM_callout_vector MEM_callouts[MEM_callouts_max];

extern bool isa_memory_hole_15mb;
extern bool isa_memory_hole_15mb;

bool a20_guest_changeable = true;
bool a20_fake_changeable = false;
Expand Down Expand Up @@ -1420,9 +1422,6 @@ uint16_t CPU_Pop16(void);

static bool cmos_reset_type_9_sarcastic_win31_comments=true;

void CPU_SetResetSignal(int x);
bool CPU_DynamicCoreCannotUseCPPExceptions(void);

void On_Software_286_int15_block_move_return(unsigned char code) {
uint16_t vec_seg,vec_off;

Expand Down Expand Up @@ -1461,10 +1460,8 @@ void On_Software_286_int15_block_move_return(unsigned char code) {
CPU_IRET(false,0);

/* force execution change (FIXME: Is there a better way to do this?) */
if (CPU_DynamicCoreCannotUseCPPExceptions())
CPU_SetResetSignal(4);
else
throw int(4);
throw int(4);
/* does not return */
}

void On_Software_286_reset_vector(unsigned char code) {
Expand Down Expand Up @@ -1504,10 +1501,8 @@ void On_Software_286_reset_vector(unsigned char code) {
reg_eip = vec_off;

/* force execution change (FIXME: Is there a better way to do this?) */
if (CPU_DynamicCoreCannotUseCPPExceptions())
CPU_SetResetSignal(4);
else
throw int(4);
throw int(4);
/* does not return */
}

void CPU_Exception_Level_Reset();
Expand Down Expand Up @@ -1585,10 +1580,7 @@ void On_Software_CPU_Reset() {
LOG_MSG("PC-98 reset and continue: RETF to %04x:%04x",SegValue(cs),reg_ip);

/* force execution change (FIXME: Is there a better way to do this?) */
if (CPU_DynamicCoreCannotUseCPPExceptions())
CPU_SetResetSignal(4);
else
throw int(4);
throw int(4);
/* does not return */
}
}
Expand All @@ -1608,10 +1600,16 @@ void On_Software_CPU_Reset() {
}
}

if (CPU_DynamicCoreCannotUseCPPExceptions())
CPU_SetResetSignal(3);
else
throw int(3);
#if C_DYNAMIC_X86
/* this technique is NOT reliable when running the dynamic core! */
if (cpudecoder == &CPU_Core_Dyn_X86_Run || cpudecoder == &CPU_Core_Dynrec_Run) {
LOG_MSG("Warning: C++ exception method is not compatible with dynamic core when emulating reset");
RebootLanguage("");
}
#endif

throw int(3);
/* does not return */
}

/* Some PC-98 code uses this register to know if the 16MB "memory hole" is open,
Expand Down Expand Up @@ -1805,19 +1803,15 @@ HostPt GetMemBase(void) { return MemBase; }
/*! \brief REDOS.COM utility command on drive Z: to trigger restart of the DOS kernel
*/
class REDOS : public Program {
public:
/*! \brief Program entry point, when the command is run */
void Run(void) override {
if (cmd->FindExist("/?", false) || cmd->FindExist("-?", false)) {
WriteOut("Reboots the kernel of DOSBox-X's emulated DOS.\n\nRE-DOS\n");
return;
}

if (CPU_DynamicCoreCannotUseCPPExceptions())
CPU_SetResetSignal(6);
else
throw int(6);
public:
/*! \brief Program entry point, when the command is run */
void Run(void) override {
if (cmd->FindExist("/?", false) || cmd->FindExist("-?", false)) {
WriteOut("Reboots the kernel of DOSBox-X's emulated DOS.\n\nRE-DOS\n");
return;
}
throw int(6);
}
};

void REDOS_ProgramStart(Program * * make) {
Expand Down