[Qemu-devel] [RFC] acpi: add reset register to fadt

[Reza Jelveh <fishman@saucelabs.com>]

Some operating systems such as FreeBSD and Mac OSX need the reset_register
section of the FADT filled to know which port to write to for a system reset.

What is the right way to set the reset_val and the reset addr in this case?
---
 hw/i386/acpi-build.c | 5 +++++
 hw/i386/acpi-defs.h  | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index d0a5c85..21c1453 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -361,6 +361,11 @@ static void fadt_setup(AcpiFadtDescriptorRev1 *fadt, AcpiPmInfo *pm)
                               (1 << ACPI_FADT_F_SLP_BUTTON) |
                               (1 << ACPI_FADT_F_RTC_S4));
     fadt->flags |= cpu_to_le32(1 << ACPI_FADT_F_USE_PLATFORM_CLOCK);
+    fadt->flags |= cpu_to_le32(1 << ACPI_FADT_F_RESET_REG_SUP);
+    fadt->reset_val = 0xf;
+    fadt->reset_reg.address_space_id   = aml_system_io;
+    fadt->reset_reg.register_bit_width = 8;
+    fadt->reset_reg.address            = ICH9_RST_CNT_IOPORT;
     /* APIC destination mode ("Flat Logical") has an upper limit of 8 CPUs
      * For more than 8 CPUs, "Clustered Logical" mode has to be used
      */
diff --git a/hw/i386/acpi-defs.h b/hw/i386/acpi-defs.h
index c4468f8..960c833 100644
--- a/hw/i386/acpi-defs.h
+++ b/hw/i386/acpi-defs.h
@@ -132,6 +132,8 @@ struct AcpiFadtDescriptorRev1
     uint8_t  reserved4a;             /* Reserved */
     uint8_t  reserved4b;             /* Reserved */
     uint32_t flags;
+    Acpi20GenericAddress reset_reg;
+    uint8_t reset_val;
 } QEMU_PACKED;
 typedef struct AcpiFadtDescriptorRev1 AcpiFadtDescriptorRev1;
 
-- 
2.3.4