hw/arm: new interface for devices which need to behave differently for kernel boot

For ARM we have a little minimalist bootloader in hw/arm/boot.c which
takes the place of firmware if we're directly booting a Linux kernel.
Unfortunately a few devices need special case handling in this situation
to do the initialization which on real hardware would be done by
firmware. (In particular if we're booting a kernel in NonSecure state
then we need to make a TZ-aware GIC put all its interrupts into Group 1,
or the guest will be unable to use them.)

Create a new QOM interface which can be implemented by devices which
need to do something different from their default reset behaviour.
The callback will be called after machine initialization and before
first reset.

Suggested-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1441383782-24378-3-git-send-email-peter.maydell@linaro.org

1 files changed, 34 insertions, 0 deletions

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 5b969cda1c..bef451b3b2 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -10,6 +10,7 @@
 #include "config.h"
 #include "hw/hw.h"
 #include "hw/arm/arm.h"
+#include "hw/arm/linux-boot-if.h"
 #include "sysemu/sysemu.h"
 #include "hw/boards.h"
 #include "hw/loader.h"
@@ -555,6 +556,20 @@ static void load_image_to_fw_cfg(FWCfgState *fw_cfg, uint16_t size_key,
     fw_cfg_add_bytes(fw_cfg, data_key, data, size);
 }
 
+static int do_arm_linux_init(Object *obj, void *opaque)
+{
+    if (object_dynamic_cast(obj, TYPE_ARM_LINUX_BOOT_IF)) {
+        ARMLinuxBootIf *albif = ARM_LINUX_BOOT_IF(obj);
+        ARMLinuxBootIfClass *albifc = ARM_LINUX_BOOT_IF_GET_CLASS(obj);
+        struct arm_boot_info *info = opaque;
+
+        if (albifc->arm_linux_init) {
+            albifc->arm_linux_init(albif, info->secure_boot);
+        }
+    }
+    return 0;
+}
+
 static void arm_load_kernel_notify(Notifier *notifier, void *data)
 {
     CPUState *cs;
@@ -778,6 +793,12 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
         if (info->nb_cpus > 1) {
             info->write_secondary_boot(cpu, info);
         }
+
+        /* Notify devices which need to fake up firmware initialization
+         * that we're doing a direct kernel boot.
+         */
+        object_child_foreach_recursive(object_get_root(),
+                                       do_arm_linux_init, info);
     }
     info->is_linux = is_linux;
 
@@ -803,3 +824,16 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
         qemu_register_reset(do_cpu_reset, ARM_CPU(cs));
     }
 }
+
+static const TypeInfo arm_linux_boot_if_info = {
+    .name = TYPE_ARM_LINUX_BOOT_IF,
+    .parent = TYPE_INTERFACE,
+    .class_size = sizeof(ARMLinuxBootIfClass),
+};
+
+static void arm_linux_boot_register_types(void)
+{
+    type_register_static(&arm_linux_boot_if_info);
+}
+
+type_init(arm_linux_boot_register_types)