Commit 67736a25 authored by Shannon Zhao's avatar Shannon Zhao Committed by Peter Maydell
Browse files

ARM: virt: Don't generate RTC ACPI device when using UEFI 



When booting the VM with UEFI, UEFI takes ownership of the RTC hardware.
While UEFI can use libfdt to disable the RTC device node in the DTB that
it passes to the OS, it cannot modify AML. Therefore, we won't generate
the RTC ACPI device at all when using UEFI.

Signed-off-by: default avatarShannon Zhao <shannon.zhao@linaro.org>
Acked-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: default avatarLaszlo Ersek <lersek@redhat.com>
Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Message-id: 1452867091-4023-1-git-send-email-shannon.zhao@linaro.org
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent ade0d0c0

hw/arm/virt-acpi-build.c

+5 −19
Original line number Diff line number Diff line
@@ -94,23 +94,6 @@ static void acpi_dsdt_add_uart(Aml *scope, const MemMapEntry *uart_memmap, 
    aml_append(scope, dev);

}



static void acpi_dsdt_add_rtc(Aml *scope, const MemMapEntry *rtc_memmap,

                                          uint32_t rtc_irq)

{

    Aml *dev = aml_device("RTC0");

    aml_append(dev, aml_name_decl("_HID", aml_string("LNRO0013")));

    aml_append(dev, aml_name_decl("_UID", aml_int(0)));



    Aml *crs = aml_resource_template();

    aml_append(crs, aml_memory32_fixed(rtc_memmap->base,

                                       rtc_memmap->size, AML_READ_WRITE));

    aml_append(crs,

               aml_interrupt(AML_CONSUMER, AML_LEVEL, AML_ACTIVE_HIGH,

                             AML_EXCLUSIVE, &rtc_irq, 1));

    aml_append(dev, aml_name_decl("_CRS", crs));

    aml_append(scope, dev);

}



static void acpi_dsdt_add_flash(Aml *scope, const MemMapEntry *flash_memmap)

{

    Aml *dev, *crs;
@@ -571,12 +554,15 @@ build_dsdt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info) 
    /* Reserve space for header */

    acpi_data_push(dsdt->buf, sizeof(AcpiTableHeader));



    /* When booting the VM with UEFI, UEFI takes ownership of the RTC hardware.

     * While UEFI can use libfdt to disable the RTC device node in the DTB that

     * it passes to the OS, it cannot modify AML. Therefore, we won't generate

     * the RTC ACPI device at all when using UEFI.

     */

    scope = aml_scope("\\_SB");

    acpi_dsdt_add_cpus(scope, guest_info->smp_cpus);

    acpi_dsdt_add_uart(scope, &memmap[VIRT_UART],

                       (irqmap[VIRT_UART] + ARM_SPI_BASE));

    acpi_dsdt_add_rtc(scope, &memmap[VIRT_RTC],

                      (irqmap[VIRT_RTC] + ARM_SPI_BASE));

    acpi_dsdt_add_flash(scope, &memmap[VIRT_FLASH]);

    acpi_dsdt_add_virtio(scope, &memmap[VIRT_MMIO],

                    (irqmap[VIRT_MMIO] + ARM_SPI_BASE), NUM_VIRTIO_TRANSPORTS);