[librm] Use explicit operand size when pushing a label address
We currently use "push $1f" within inline assembly to push the address
of the real-mode code fragment, relying on the assembler to treat this
as "pushl" for 32-bit code or "pushq" for 64-bit code.
As of binutils commit 5cc0077 ("x86: further adjust extend-to-32bit-
address conditions"), first included in binutils-2.41, this implicit
operand size is no longer calculated as expected and 64-bit builds
will fail with
Error: operand size mismatch for `push'
Fix by adding an explicit operand size to the "push" instruction.
Originally-fixed-by: Justin Cano <jstncno@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
diff --git a/src/arch/x86/include/librm.h b/src/arch/x86/include/librm.h
index 5196d39..40f0754 100644
--- a/src/arch/x86/include/librm.h
+++ b/src/arch/x86/include/librm.h
@@ -250,8 +250,10 @@
/* CODE_DEFAULT: restore default .code32/.code64 directive */
#ifdef __x86_64__
#define CODE_DEFAULT ".code64"
+#define STACK_DEFAULT "q"
#else
#define CODE_DEFAULT ".code32"
+#define STACK_DEFAULT "l"
#endif
/* LINE_SYMBOL: declare a symbol for the current source code line */
@@ -268,7 +270,7 @@
/* REAL_CODE: declare a fragment of code that executes in real mode */
#define REAL_CODE( asm_code_str ) \
- "push $1f\n\t" \
+ "push" STACK_DEFAULT " $1f\n\t" \
"call real_call\n\t" \
TEXT16_CODE ( "\n1:\n\t" \
asm_code_str \
@@ -277,7 +279,7 @@
/* PHYS_CODE: declare a fragment of code that executes in flat physical mode */
#define PHYS_CODE( asm_code_str ) \
- "push $1f\n\t" \
+ "push" STACK_DEFAULT " $1f\n\t" \
"call phys_call\n\t" \
".section \".text.phys\", \"ax\", @progbits\n\t"\
"\n" LINE_SYMBOL "\n\t" \
