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authorH. Peter Anvin <hpa@zytor.com>2007-07-11 12:18:38 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-12 10:55:54 -0700
commitf7f4a5fbd21bf7fc4f207ddaf5126c78c0d1e0b5 (patch)
tree497fa10d3eca17e9872b54adea55cf8ed6bf9baa /arch/i386/boot
parent8afd2af88921c2cb1c9540cecd0714da7ae4fcd0 (diff)
Header file to produce 16-bit code with gcc
gcc for i386 can be used with the assembly prefix ".code16gcc" to generate 16-bit (real-mode) code. This header file provides the assembly prefix. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/i386/boot')
-rw-r--r--arch/i386/boot/code16gcc.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/i386/boot/code16gcc.h b/arch/i386/boot/code16gcc.h
new file mode 100644
index 000000000000..3bd848093b9d
--- /dev/null
+++ b/arch/i386/boot/code16gcc.h
@@ -0,0 +1,15 @@
+/*
+ * code16gcc.h
+ *
+ * This file is -include'd when compiling 16-bit C code.
+ * Note: this asm() needs to be emitted before gcc omits any code.
+ * Depending on gcc version, this requires -fno-unit-at-a-time or
+ * -fno-toplevel-reorder.
+ *
+ * Hopefully gcc will eventually have a real -m16 option so we can
+ * drop this hack long term.
+ */
+
+#ifndef __ASSEMBLY__
+asm(".code16gcc");
+#endif