[Qemu-devel] [PULL 3/7] arm: boot: Add secure_board_setup flag

[Peter Maydell <peter.maydell@linaro.org>]

From: Peter Crosthwaite <crosthwaitepeter@gmail.com>

Add a flag that when set, will cause the primary CPU to start in secure
mode, even if the overall boot is non-secure. This is useful for when
there is a board-setup blob that needs to run from secure mode, but
device and secondary CPU init should still be done as-normal for a non-
secure boot.

Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: d1170774d5446d715fced7739edfc61a5be931f9.1447007690.git.crosthwaite.peter@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/boot.c        | 10 +++++++++-
 include/hw/arm/arm.h |  6 ++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index b0879a5..75f69bf 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -11,6 +11,7 @@
 #include "hw/hw.h"
 #include "hw/arm/arm.h"
 #include "hw/arm/linux-boot-if.h"
+#include "sysemu/kvm.h"
 #include "sysemu/sysemu.h"
 #include "hw/boards.h"
 #include "hw/loader.h"
@@ -495,7 +496,8 @@ static void do_cpu_reset(void *opaque)
                 }
 
                 /* Set to non-secure if not a secure boot */
-                if (!info->secure_boot) {
+                if (!info->secure_boot &&
+                    (cs != first_cpu || !info->secure_board_setup)) {
                     /* Linux expects non-secure state */
                     env->cp15.scr_el3 |= SCR_NS;
                 }
@@ -598,6 +600,12 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
     struct arm_boot_info *info =
         container_of(n, struct arm_boot_info, load_kernel_notifier);
 
+    /* The board code is not supposed to set secure_board_setup unless
+     * running its code in secure mode is actually possible, and KVM
+     * doesn't support secure.
+     */
+    assert(!(info->secure_board_setup && kvm_enabled()));
+
     /* Load the kernel.  */
     if (!info->kernel_filename || info->firmware_loaded) {
 
diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
index 67ba7db..c26b0e3 100644
--- a/include/hw/arm/arm.h
+++ b/include/hw/arm/arm.h
@@ -97,6 +97,12 @@ struct arm_boot_info {
     hwaddr board_setup_addr;
     void (*write_board_setup)(ARMCPU *cpu,
                               const struct arm_boot_info *info);
+
+    /* If set, the board specific loader/setup blob will be run from secure
+     * mode, regardless of secure_boot. The blob becomes responsible for
+     * changing to non-secure state if implementing a non-secure boot
+     */
+    bool secure_board_setup;
 };
 
 /**
-- 
1.9.1