Adding upstream version 2.06.upstream/2.06upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/include/grub/i386/wrmsr.h b/include/grub/i386/wrmsr.h
new file mode 100644
index 0000000..dea60ae
--- /dev/null
+++ b/include/grub/i386/wrmsr.h
@@ -0,0 +1,35 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2019  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_WRMSR_H
+#define GRUB_WRMSR_H 1
+
+/*
+ * TODO: Add a general protection exception handler.
+ *       Accessing a reserved or unimplemented MSR address results in a GP#.
+ */
+
+static inline void
+grub_msr_write(grub_uint32_t msr_id, grub_uint64_t msr_value)
+{
+  grub_uint32_t low = msr_value, high = msr_value >> 32;
+
+  asm volatile ("wrmsr" : : "c" (msr_id), "a" (low), "d" (high));
+}
+
+#endif /* GRUB_WRMSR_H */