diff options
Diffstat (limited to 'docs/specs')
| -rw-r--r-- | docs/specs/acpi_cpu_hotplug.txt | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt index ee219c8358..4e65286ff5 100644 --- a/docs/specs/acpi_cpu_hotplug.txt +++ b/docs/specs/acpi_cpu_hotplug.txt @@ -30,6 +30,18 @@ Register block base address: Register block size: ACPI_CPU_HOTPLUG_REG_LEN = 12 +All accesses to registers described below, imply little-endian byte order. + +Reserved resisters behavior: + - write accesses are ignored + - read accesses return all bits set to 0. + +The last stored value in 'CPU selector' must refer to a possible CPU, otherwise + - reads from any register return 0 + - writes to any other register are ignored until valid value is stored into it +On QEMU start, 'CPU selector' is initialized to a valid value, on reset it +keeps the current value. + read access: offset: [0x0-0x3] reserved @@ -86,9 +98,3 @@ write access: ACPI_DEVICE_OST QMP event from QEMU to external applications with current values of OST event and status registers. other values: reserved - -Selecting CPU device beyond possible range has no effect on platform: - - write accesses to CPU hot-plug registers not documented above are - ignored - - read accesses to CPU hot-plug registers not documented above return - all bits set to 0. |