core: Simplify changes to SREG

[simavr] / simavr / sim / sim_core.c

diff --git a/simavr/sim/sim_core.c b/simavr/sim/sim_core.c
index a8df91d..31c2ab3 100644 (file)
--- a/simavr/sim/sim_core.c
+++ b/simavr/sim/sim_core.c
@@ -130,10 +130,10 @@ static inline void _avr_set_r(avr_t * avr, uint8_t r, uint8_t v)
        REG_TOUCH(avr, r);
 
        if (r == R_SREG) {
-               avr->data[r] = v;
+               avr->data[R_SREG] = v;
                // unsplit the SREG
                for (int i = 0; i < 8; i++)
-                       avr->sreg[i] = (avr->data[R_SREG] & (1 << i)) != 0;
+                       avr->sreg[i] = (v & (1 << i)) != 0;
                SREG();
        }
        if (r > 31) {
@@ -181,8 +181,22 @@ static inline void _avr_set_ram(avr_t * avr, uint16_t addr, uint8_t v)
  */
 static inline uint8_t _avr_get_ram(avr_t * avr, uint16_t addr)
 {
-       if (addr > 31 && addr < 256) {
+       if (addr == R_SREG) {
+               /*
+                * SREG is special it's reconstructed when read
+                * while the core itself uses the "shortcut" array
+                */
+               avr->data[R_SREG] = 0;
+               for (int i = 0; i < 8; i++)
+                       if (avr->sreg[i] > 1) {
+                               printf("** Invalid SREG!!\n");
+                               CRASH();
+                       } else if (avr->sreg[i])
+                               avr->data[R_SREG] |= (1 << i);
+               
+       } else if (addr > 31 && addr < 256) {
                uint8_t io = AVR_DATA_TO_IO(addr);
+               
                if (avr->io[io].r.c)
                        avr->data[addr] = avr->io[io].r.c(avr, addr, avr->io[io].r.param);
                
@@ -301,7 +315,7 @@ void avr_dump_state(avr_t * avr)
 #define get_r_d_10(o) \
                const uint8_t r = ((o >> 5) & 0x10) | (o & 0xf); \
                const uint8_t d = (o >> 4) & 0x1f;\
-               const uint8_t vd = avr->data[d], vr =avr->data[r];
+               const uint8_t vd = avr->data[d], vr = avr->data[r];
 #define get_k_r16(o) \
                const uint8_t r = 16 + ((o >> 4) & 0xf); \
                const uint8_t k = ((o & 0x0f00) >> 4) | (o & 0xf);
@@ -1197,15 +1211,12 @@ uint16_t avr_run_one(avr_t * avr)
                                        uint8_t r = (opcode >> 4) & 0x1f;
                                        uint8_t A = ((((opcode >> 9) & 3) << 4) | ((opcode) & 0xf)) + 32;
                                        STATE("out %s, %s[%02x]\n", avr_regname(A), avr_regname(r), avr->data[r]);
-                                       // todo: store to IO register
                                        _avr_set_ram(avr, A, avr->data[r]);
-                               //      avr->data[A] = ;
                                }       break;
                                case 0xb000: {  // IN Rd,A 1011 0AAr rrrr AAAA
                                        uint8_t r = (opcode >> 4) & 0x1f;
                                        uint8_t A = ((((opcode >> 9) & 3) << 4) | ((opcode) & 0xf)) + 32;
                                        STATE("in %s, %s[%02x]\n", avr_regname(r), avr_regname(A), avr->data[A]);
-                                       // todo: get the IO register
                                        _avr_set_r(avr, r, _avr_get_ram(avr, A));
                                }       break;
                                default: _avr_invalid_opcode(avr);