@@ -480,7 +480,6 @@ struct StrongARMGPIOInfo {
uint32_t rising;
uint32_t falling;
uint32_t status;
- uint32_t gpsr;
uint32_t gafr;
uint32_t prev_level;
@@ -544,14 +543,14 @@ static uint64_t strongarm_gpio_read(void *opaque, hwaddr offset,
return s->dir;
case GPSR: /* GPIO Pin-Output Set registers */
- DPRINTF("%s: Read from a write-only register 0x" TARGET_FMT_plx "\n",
- __func__, offset);
- return s->gpsr; /* Return last written value. */
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "strongarm GPIO: read from write only register GPSR\n");
+ return 0;
case GPCR: /* GPIO Pin-Output Clear registers */
- DPRINTF("%s: Read from a write-only register 0x" TARGET_FMT_plx "\n",
- __func__, offset);
- return 31337; /* Specified as unpredictable in the docs. */
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "strongarm GPIO: read from write only register GPCR\n");
+ return 0;
case GRER: /* GPIO Rising-Edge Detect Enable registers */
return s->rising;
@@ -590,7 +589,6 @@ static void strongarm_gpio_write(void *opaque, hwaddr offset,
case GPSR: /* GPIO Pin-Output Set registers */
s->olevel |= value;
strongarm_gpio_handler_update(s);
- s->gpsr = value;
break;
case GPCR: /* GPIO Pin-Output Clear registers */
The StrongARM GPIO GPSR and GPCR registers are write-only, with reads being undefined behaviour. Instead of having GPCR return 31337 and GPSR return the value last written, make both log the guest error and return 0. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- hw/arm/strongarm.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-)