xvisor: fix build with gcc-10

* with gcc-10 (which doesn't include -fcommon by default) it fails like this:
  aarch64-oe-linux-ld: error: TOPDIR/BUILD/work/raspberrypi3_64-oe-linux/xvisor/git-r0/git/build/drivers/mmc/core/mmc.o: multiple definition of 'sdio_func_type'
  aarch64-oe-linux-ld: error: TOPDIR/BUILD/work/raspberrypi3_64-oe-linux/xvisor/git-r0/git/build/drivers/mmc/core/sdio_bus.o: multiple definition of 'sdio_func_type'
  aarch64-oe-linux-ld: error: TOPDIR/BUILD/work/raspberrypi3_64-oe-linux/xvisor/git-r0/git/build/drivers/mmc/core/sdio_io.o: multiple definition of 'sdio_func_type'
  aarch64-oe-linux-ld: error: TOPDIR/BUILD/work/raspberrypi3_64-oe-linux/xvisor/git-r0/git/build/drivers/mmc/core/sdio.o: multiple definition of 'sdio_func_type'
  aarch64-oe-linux-ld: TOPDIR/BUILD/work/raspberrypi3_64-oe-linux/xvisor/git-r0/git/build/drivers/mmc/core/core.o: previous definition here

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/recipes-extended/xvisor/files/0001-EMULATORS-Allow-Xvisor-to-compile-with-gcc-10.patch b/recipes-extended/xvisor/files/0001-EMULATORS-Allow-Xvisor-to-compile-with-gcc-10.patch
new file mode 100644
index 00000000..221a314c
--- /dev/null
+++ b/recipes-extended/xvisor/files/0001-EMULATORS-Allow-Xvisor-to-compile-with-gcc-10.patch
@@ -0,0 +1,55 @@
+From 417184cc41cfd33ae7b4c11c8396e0f47f43e2ba Mon Sep 17 00:00:00 2001
+From: Jean-Christophe Dubois <jcd@tribudubois.net>
+Date: Fri, 8 May 2020 15:17:36 +0200
+Subject: [PATCH] EMULATORS: Allow Xvisor to compile with gcc 10.
+
+With gcc 10 because some header files do not declare some variable
+definition as extern, the variable get duplicated in all files
+using it.
+
+This patch allow xvisor to compile with the latest gcc.
+
+Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
+Reviewed-by: Anup Patel <anup@brainfault.org>
+---
+ drivers/mmc/core/core.h    |  2 +-
+ emulators/display/drawfn.h | 10 +++++-----
+ 2 files changed, 6 insertions(+), 6 deletions(-)
+
+diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
+index d75d135a..e2ca3141 100644
+--- a/drivers/mmc/core/core.h
++++ b/drivers/mmc/core/core.h
+@@ -64,7 +64,7 @@ int mmc_go_idle(struct mmc_host *host);
+  * Note: Must be called with host->lock held.
+  */
+ extern struct vmm_bus sdio_bus_type;
+-struct vmm_device_type sdio_func_type;
++extern struct vmm_device_type sdio_func_type;
+ 
+ int __sdio_attach(struct mmc_host *host);
+ 
+diff --git a/emulators/display/drawfn.h b/emulators/display/drawfn.h
+index f9163cff..385deaf6 100644
+--- a/emulators/display/drawfn.h
++++ b/emulators/display/drawfn.h
+@@ -69,14 +69,14 @@ typedef void (*drawfn)(struct vmm_surface *,
+                                 DRAWFN_ORDER_MAX * \
+                                 DRAWFN_FORMAT_MAX)
+ 
+-drawfn drawfn_surface_fntable_8[DRAWFN_FNTABLE_SIZE];
++extern drawfn drawfn_surface_fntable_8[DRAWFN_FNTABLE_SIZE];
+ 
+-drawfn drawfn_surface_fntable_15[DRAWFN_FNTABLE_SIZE];
++extern drawfn drawfn_surface_fntable_15[DRAWFN_FNTABLE_SIZE];
+ 
+-drawfn drawfn_surface_fntable_16[DRAWFN_FNTABLE_SIZE];
++extern drawfn drawfn_surface_fntable_16[DRAWFN_FNTABLE_SIZE];
+ 
+-drawfn drawfn_surface_fntable_24[DRAWFN_FNTABLE_SIZE];
++extern drawfn drawfn_surface_fntable_24[DRAWFN_FNTABLE_SIZE];
+ 
+-drawfn drawfn_surface_fntable_32[DRAWFN_FNTABLE_SIZE];
++extern drawfn drawfn_surface_fntable_32[DRAWFN_FNTABLE_SIZE];
+ 
+ #endif