File ipxe.fb2bedcff3ab30ca2a4bed1aa821d1b1c8f9cfae.patch of Package xen
From: Michael Brown <mcb30@ipxe.org>
Date: Tue, 7 Apr 2015 06:40:42 +0100
Subject: fb2bedcff3ab30ca2a4bed1aa821d1b1c8f9cfae
[libc] Add x86_64 versions of setjmp() and longjmp()
None of the x86_64 builds currently have any way of invoking these
functions. They are included only to avoid introducing unnecessary
architecture-specific dependencies into the self-test suite.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
src/arch/x86_64/Makefile | 1 +
src/arch/x86_64/core/setjmp.S | 65 ++++++++++++++++++++++++++++++++
src/arch/x86_64/include/setjmp.h | 34 +++++++++++++++++
3 files changed, 100 insertions(+)
create mode 100644 src/arch/x86_64/core/setjmp.S
create mode 100644 src/arch/x86_64/include/setjmp.h
--- a/src/arch/x86_64/Makefile
+++ b/src/arch/x86_64/Makefile
@@ -28,6 +28,7 @@ CFLAGS += -Ui386
# x86_64-specific directories containing source files
#
+SRCDIRS += arch/x86_64/core
SRCDIRS += arch/x86_64/prefix
# Include common x86 Makefile
new file mode 100644
--- /dev/null
+++ b/src/arch/x86_64/core/setjmp.S
@@ -0,0 +1,65 @@
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )
+
+ .text
+ .code64
+
+ /* Must match jmp_buf structure layout */
+ .struct 0
+env_retaddr: .quad 0
+env_stack: .quad 0
+env_rbx: .quad 0
+env_rbp: .quad 0
+env_r12: .quad 0
+env_r13: .quad 0
+env_r14: .quad 0
+env_r15: .quad 0
+ .previous
+
+/*
+ * Save stack context for non-local goto
+ */
+ .globl setjmp
+setjmp:
+ /* Save return address */
+ movq 0(%rsp), %rax
+ movq %rax, env_retaddr(%rdi)
+ /* Save stack pointer */
+ movq %rsp, env_stack(%rdi)
+ /* Save other registers */
+ movq %rbx, env_rbx(%rdi)
+ movq %rbp, env_rbp(%rdi)
+ movq %r12, env_r12(%rdi)
+ movq %r13, env_r13(%rdi)
+ movq %r14, env_r14(%rdi)
+ movq %r15, env_r15(%rdi)
+ /* Return 0 when returning as setjmp() */
+ xorq %rax, %rax
+ ret
+ .size setjmp, . - setjmp
+
+/*
+ * Non-local jump to a saved stack context
+ */
+ .globl longjmp
+longjmp:
+ /* Get result in %rax */
+ movq %rsi, %rax
+ /* Force result to non-zero */
+ testq %rax, %rax
+ jnz 1f
+ incq %rax
+1: /* Restore stack pointer */
+ movq env_stack(%rdi), %rsp
+ /* Restore other registers */
+ movq env_rbx(%rdi), %rbx
+ movq env_rbp(%rdi), %rbp
+ movq env_r12(%rdi), %r12
+ movq env_r13(%rdi), %r13
+ movq env_r14(%rdi), %r14
+ movq env_r15(%rdi), %r15
+ /* Replace return address on the new stack */
+ popq %rcx /* discard */
+ pushq env_retaddr(%rdi)
+ /* Return to setjmp() caller */
+ ret
+ .size longjmp, . - longjmp
new file mode 100644
--- /dev/null
+++ b/src/arch/x86_64/include/setjmp.h
@@ -0,0 +1,34 @@
+#ifndef _SETJMP_H
+#define _SETJMP_H
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+
+/** A jump buffer */
+typedef struct {
+ /** Saved return address */
+ uint64_t retaddr;
+ /** Saved stack pointer */
+ uint64_t stack;
+ /** Saved %rbx */
+ uint64_t rbx;
+ /** Saved %rbp */
+ uint64_t rbp;
+ /** Saved %r12 */
+ uint64_t r12;
+ /** Saved %r13 */
+ uint64_t r13;
+ /** Saved %r14 */
+ uint64_t r14;
+ /** Saved %r15 */
+ uint64_t r15;
+} jmp_buf[1];
+
+extern int __asmcall __attribute__ (( returns_twice ))
+setjmp ( jmp_buf env );
+
+extern void __asmcall __attribute__ (( noreturn ))
+longjmp ( jmp_buf env, int val );
+
+#endif /* _SETJMP_H */
