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realemu: ignore access to CMOS/RTC address/data registers

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the kernel wont allow access to i/o ports 0x70/0x71, so
ignore the access. reads return 0xFF. this fixes vesa on
lenovo e540.
This commit is contained in:
cinap_lenrek 2015-05-09 07:50:05 +02:00
parent 4547b5070c
commit 0da5888901
1 changed files with 12 additions and 0 deletions
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12
sys/src/cmd/aux/realemu/main.c
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@ -29,6 +29,7 @@ static int realmemfd;
static int cputrace;
static int porttrace;
static Pit pit[3];
static uchar rtcaddr;
static vlong pitclock;
@ -186,6 +187,12 @@ rport(void *, ulong p, int len)
case 0x65: /* A20 gate */
w = 1 << 2;
break;
case 0x70: /* RTC addr */
w = rtcaddr;
break;
case 0x71: /* RTC data */
w = 0xFF;
break;
case 0x80: /* extra dma registers (temp) */
case 0x84:
case 0x85:
@ -244,6 +251,11 @@ wport(void *, ulong p, ulong w, int len)
case 0x64: /* KB controller input buffer (ISA, EISA) */
case 0x65: /* A20 gate (bit 2) */
break;
case 0x70: /* RTC addr */
rtcaddr = w & 0xFF;
break;
case 0x71: /* RTC data */
break;
case 0x80:
case 0x84:
case 0x85: