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| author | Paolo Bonzini <pbonzini@redhat.com> | 2012-10-01 14:22:07 +0200 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-10-05 08:02:30 -0500 |
| commit | e67edb943f0c812530aaae2491da56f9542f928b (patch) | |
| tree | 882a919b6e3490b4050d6c914d2a4c22bf0ea1e8 /hw/mc146818rtc_regs.h | |
| parent | b6db4aca20e9af4f62c9c9e08b9b9672a6ed3390 (diff) | |
| download | qemu-e67edb943f0c812530aaae2491da56f9542f928b.zip qemu-e67edb943f0c812530aaae2491da56f9542f928b.tar.gz qemu-e67edb943f0c812530aaae2491da56f9542f928b.tar.bz2 | |
rtc: map CMOS index 0x37 to 0x32 on read and writes
QEMU's attempt to implement the century byte cover two possible places
for the byte. A common one on modern chipsets is 0x32, but QEMU also
stores the value in 0x37 (apparently for IBM PS/2 compatibility---it's
only been 25 years). To simplify the implementation of the century
byte, store it only at 0x32 but remap transparently 0x37 to 0x32 when
reading and writing from CMOS.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw/mc146818rtc_regs.h')
| -rw-r--r-- | hw/mc146818rtc_regs.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/hw/mc146818rtc_regs.h b/hw/mc146818rtc_regs.h index fc10076..ccdee42 100644 --- a/hw/mc146818rtc_regs.h +++ b/hw/mc146818rtc_regs.h @@ -44,6 +44,10 @@ #define RTC_REG_C 12 #define RTC_REG_D 13 +/* PC cmos mappings */ +#define RTC_CENTURY 0x32 +#define RTC_IBM_PS2_CENTURY_BYTE 0x37 + #define REG_A_UIP 0x80 #define REG_B_SET 0x80 |