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Add special status word in bus error; add RR handling as well.
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Add setting FC to 7 when doing int ack.
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@Spritetm
Spritetm committed Jun 19, 2024
1 parent 8155918 commit 07bcac8
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Showing 2 changed files with 56 additions and 10 deletions.
8 changes: 6 additions & 2 deletions Musashi/m68k_in.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9298,7 +9298,7 @@ M68KMAKE_OP(rte, 32, ., .)
new_sr = m68ki_pull_16();
new_pc = m68ki_pull_32();
m68ki_fake_pull_16(); /* format word */
m68ki_fake_pull_16(); /* special status word */
uint ssw=m68ki_pull_16(); /* special status word */
m68ki_fake_pull_32(); /* fault address */
m68ki_fake_pull_16(); /* unused/reserved */
m68ki_fake_pull_16(); /* data output buffer */
Expand All @@ -9314,7 +9314,11 @@ M68KMAKE_OP(rte, 32, ., .)
m68ki_fake_pull_32();
m68ki_fake_pull_32();
m68ki_fake_pull_32();
m68ki_jump(new_pc);
if (ssw&0x8000) { //ReRun flag set - jump over erroneous instruction
m68ki_jump(m68ki_cpu.mmu_tmp_buserror_newpc);
} else {
m68ki_jump(new_pc);
}
m68ki_set_sr(new_sr);
CPU_INSTR_MODE = INSTRUCTION_YES;
CPU_RUN_MODE = RUN_MODE_NORMAL;
Expand Down
58 changes: 50 additions & 8 deletions Musashi/m68kcpu.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1001,6 +1001,15 @@ typedef struct
void (*set_fc_callback)(unsigned int new_fc); /* Called when the CPU function code changes */
void (*instr_hook_callback)(unsigned int pc); /* Called every instruction cycle prior to execution */

//bus error special register support, backported from Mame
uint16 mmu_tmp_fc; /* temporary hack: function code for the mmu (moves) */
uint16 mmu_tmp_rw; /* temporary hack: read/write (1/0) for the mmu */
uint8 mmu_tmp_sz; /* temporary hack: size for mmu */
uint32 mmu_tmp_buserror_newpc; /* pc after the erroneous instruction, for rr */

uint16 mmu_tmp_buserror_fc; /* temporary hack: (first) bus error fc */
uint16 mmu_tmp_buserror_rw; /* temporary hack: (first) bus error rw */
uint16 mmu_tmp_buserror_sz; /* temporary hack: (first) bus error size` */
} m68ki_cpu_core;


Expand Down Expand Up @@ -1042,6 +1051,10 @@ extern uint pmmu_translate_addr(uint addr_in);
*/
static inline uint m68ki_read_imm_16(void)
{
m68ki_cpu.mmu_tmp_fc = m68ki_cpu.s_flag | FUNCTION_CODE_USER_PROGRAM;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = 2;

m68ki_set_fc(FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error(REG_PC, MODE_READ, FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */

Expand Down Expand Up @@ -1087,6 +1100,10 @@ static inline uint m68ki_read_imm_32(void)
#endif
#endif

m68ki_cpu.mmu_tmp_fc = m68ki_cpu.s_flag | FUNCTION_CODE_USER_PROGRAM;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = 4;

#if M68K_EMULATE_PREFETCH
uint temp_val;

Expand Down Expand Up @@ -1127,7 +1144,9 @@ static inline uint m68ki_read_imm_32(void)
*/
static inline uint m68ki_read_8_fc(uint address, uint fc)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = 1;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */

#if M68K_EMULATE_PMMU
Expand All @@ -1139,7 +1158,9 @@ static inline uint m68ki_read_8_fc(uint address, uint fc)
}
static inline uint m68ki_read_16_fc(uint address, uint fc)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = 2;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error_010_less(address, MODE_READ, fc); /* auto-disable (see m68kcpu.h) */

Expand All @@ -1152,7 +1173,9 @@ static inline uint m68ki_read_16_fc(uint address, uint fc)
}
static inline uint m68ki_read_32_fc(uint address, uint fc)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = 4;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error_010_less(address, MODE_READ, fc); /* auto-disable (see m68kcpu.h) */

Expand All @@ -1166,7 +1189,9 @@ static inline uint m68ki_read_32_fc(uint address, uint fc)

static inline void m68ki_write_8_fc(uint address, uint fc, uint value)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 0;
m68ki_cpu.mmu_tmp_sz = 1;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */

#if M68K_EMULATE_PMMU
Expand All @@ -1178,7 +1203,9 @@ static inline void m68ki_write_8_fc(uint address, uint fc, uint value)
}
static inline void m68ki_write_16_fc(uint address, uint fc, uint value)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 0;
m68ki_cpu.mmu_tmp_sz = 2;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error_010_less(address, MODE_WRITE, fc); /* auto-disable (see m68kcpu.h) */

Expand All @@ -1191,7 +1218,9 @@ static inline void m68ki_write_16_fc(uint address, uint fc, uint value)
}
static inline void m68ki_write_32_fc(uint address, uint fc, uint value)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 0;
m68ki_cpu.mmu_tmp_sz = 4;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error_010_less(address, MODE_WRITE, fc); /* auto-disable (see m68kcpu.h) */

Expand All @@ -1206,7 +1235,9 @@ static inline void m68ki_write_32_fc(uint address, uint fc, uint value)
#if M68K_SIMULATE_PD_WRITES
static inline void m68ki_write_32_pd_fc(uint address, uint fc, uint value)
{
(void)fc;
m68ki_cpu.mmu_tmp_fc = fc;
m68ki_cpu.mmu_tmp_rw = 0;
m68ki_cpu.mmu_tmp_sz = 4;
m68ki_set_fc(fc); /* auto-disable (see m68kcpu.h) */
m68ki_check_address_error_010_less(address, MODE_WRITE, fc); /* auto-disable (see m68kcpu.h) */

Expand Down Expand Up @@ -1469,6 +1500,7 @@ static inline void m68ki_jump(uint new_pc)

static inline void m68ki_jump_vector(uint vector)
{
m68ki_set_fc(0x7); //int ack
REG_PC = (vector<<2) + REG_VBR;
REG_PC = m68ki_read_data_32(REG_PC);
m68ki_pc_changed(REG_PC);
Expand Down Expand Up @@ -1665,6 +1697,9 @@ static inline void m68ki_stack_frame_buserr(uint sr)
*/
static inline void m68ki_stack_frame_1000(uint pc, uint sr, uint vector)
{
int orig_rw = m68ki_cpu.mmu_tmp_buserror_rw; // this gets splatted by the following pushes, so save it now
int orig_fc = m68ki_cpu.mmu_tmp_buserror_fc;

/* VERSION
* NUMBER
* INTERNAL INFORMATION, 16 WORDS
Expand Down Expand Up @@ -1700,7 +1735,10 @@ static inline void m68ki_stack_frame_1000(uint pc, uint sr, uint vector)
m68ki_push_32(0);

/* SPECIAL STATUS WORD */
m68ki_push_16(0);
m68ki_push_16(orig_fc |
(((orig_fc&3)==1)?(1<<12):0) |
(((orig_fc&3)==2)?(1<<13):0) |
(orig_rw<<8));

/* 1000, VECTOR OFFSET */
m68ki_push_16(0x8000 | (vector<<2));
Expand Down Expand Up @@ -1915,6 +1953,9 @@ extern jmp_buf m68ki_bus_error_jmp_buf;
static inline void m68ki_exception_bus_error(void)
{
int i;
m68ki_cpu.mmu_tmp_buserror_fc = m68ki_cpu.mmu_tmp_fc;
m68ki_cpu.mmu_tmp_buserror_rw = m68ki_cpu.mmu_tmp_rw;
m68ki_cpu.mmu_tmp_buserror_sz = m68ki_cpu.mmu_tmp_sz;

/* If we were processing a bus error, address error, or reset,
* while writing the stack frame, this is a catastrophic failure.
Expand All @@ -1938,6 +1979,7 @@ static inline void m68ki_exception_bus_error(void)
uint sr = m68ki_init_exception();

/* Note: This is implemented for 68010 only! */
m68ki_cpu.mmu_tmp_buserror_newpc=REG_PC;
m68ki_stack_frame_1000(REG_PPC, sr, EXCEPTION_BUS_ERROR);

m68ki_jump_vector(EXCEPTION_BUS_ERROR);
Expand Down

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