Implement hardware blitter

1 files changed, 12 insertions, 10 deletions

diff --git a/vm.c b/vm.c
index 7d91eb8..5f4b1ce 100644
--- a/vm.c
+++ b/vm.c
@@ -69,12 +69,6 @@ static uint8_t flags(uint8_t *f, uint16_t v, uint8_t mask)
     return v;
 }
 
-static uint8_t port(uint8_t p, uint8_t v)
-{
-    /* TODO */
-    return p ^ v;
-}
-
 static void dump(Tr8 *vm)
 {
     uint8_t i;
@@ -113,11 +107,12 @@ static void dump(Tr8 *vm)
     fprintf(stderr, "****\n");
 }
 
-void tr8_init(Tr8 *vm, void (*write_m)(uint16_t, uint8_t), uint8_t (*read_m)(uint16_t))
+void tr8_init(Tr8 *vm, void (*write_m)(uint16_t, uint8_t), uint8_t (*read_m)(uint16_t), uint8_t (*port)(uint8_t, uint8_t))
 {
     memset(vm, 0, sizeof(Tr8));
     vm->write_m = write_m;
     vm->read_m = read_m;
+    vm->port = port;
     vm->f = IF;
 }
 
@@ -181,7 +176,7 @@ uint8_t tr8_eval(Tr8 *vm)
                         return 1;
                     }
                     /* PORT r1, r3 */
-                    vm->regs[R1(instr)] = port(vm->regs[R1(instr)], vm->regs[R3(instr)]);
+                    vm->regs[R1(instr)] = vm->port(vm->regs[R1(instr)], vm->regs[R3(instr)]);
                 }
                 else
                 {
@@ -329,7 +324,8 @@ uint8_t tr8_eval(Tr8 *vm)
                     /* BIT r1, im */
                     flags(&vm->f, vm->regs[R1(instr)] & (1 << (IMM(instr) & 7)) ? 0 : 1, ZF);
                 }
-                else {
+                else
+                {
                     if (FHL(instr))
                         /* SHL r1, im */
                         vm->regs[R1(instr)] = flags(&vm->f, vm->regs[R1(instr)] << (IMM(instr) & 7), ZF | CF | SF);
@@ -481,6 +477,12 @@ uint8_t read_m(uint16_t addr)
     return ram[addr];
 }
 
+uint8_t port(uint8_t p, uint8_t v)
+{
+    (void)p;
+    return v;
+}
+
 int main(int argc, char *argv[])
 {
     FILE *fd;
@@ -517,7 +519,7 @@ int main(int argc, char *argv[])
     }
     fclose(fd);
 
-    tr8_init(&vm, write_m, read_m);
+    tr8_init(&vm, write_m, read_m, port);
     return tr8_eval(&vm);
 }