[Qemu-devel] [PATCH 02/10] cuda: don't allow writes to port output pins

[Mark Cave-Ayland]

Use the direction registers as a mask to ensure that only input pins are
updated upon write.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---
 hw/misc/macio/cuda.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
index 23b7e0f5b0..7214e7adcb 100644
--- a/hw/misc/macio/cuda.c
+++ b/hw/misc/macio/cuda.c
@@ -359,11 +359,11 @@ static void cuda_write(void *opaque, hwaddr addr, 
uint64_t val, unsigned size)
 
     switch(addr) {
     case CUDA_REG_B:
-        s->b = val;
+        s->b = (s->b & ~s->dirb) | (val & s->dirb);
         cuda_update(s);
         break;
     case CUDA_REG_A:
-        s->a = val;
+        s->a = (s->a & ~s->dira) | (val & s->dira);
         break;
     case CUDA_REG_DIRB:
         s->dirb = val;
-- 
2.11.0