auto import from //depot/cupcake/@135843
diff --git a/libc/arch-arm/include/machine/setjmp.h b/libc/arch-arm/include/machine/setjmp.h
new file mode 100644
index 0000000..f20cab2
--- /dev/null
+++ b/libc/arch-arm/include/machine/setjmp.h
@@ -0,0 +1,87 @@
+/* $OpenBSD: setjmp.h,v 1.1 2004/02/01 05:09:49 drahn Exp $ */
+/* $NetBSD: setjmp.h,v 1.2 2001/08/25 14:45:59 bjh21 Exp $ */
+
+/*
+ * machine/setjmp.h: machine dependent setjmp-related information.
+ */
+
+#ifdef __ELF__
+#define _JBLEN 64 /* size, in longs, of a jmp_buf */
+#else
+#define _JBLEN 29 /* size, in longs, of a jmp_buf */
+#endif
+
+/*
+ * NOTE: The internal structure of a jmp_buf is *PRIVATE*
+ * This information is provided as there is software
+ * that fiddles with this with obtain the stack pointer
+ * (yes really ! and its commercial !).
+ *
+ * Description of the setjmp buffer
+ *
+ * word 0 magic number (dependant on creator)
+ * 1 - 3 f4 fp register 4
+ * 4 - 6 f5 fp register 5
+ * 7 - 9 f6 fp register 6
+ * 10 - 12 f7 fp register 7
+ * 13 fpsr fp status register
+ * 14 r4 register 4
+ * 15 r5 register 5
+ * 16 r6 register 6
+ * 17 r7 register 7
+ * 18 r8 register 8
+ * 19 r9 register 9
+ * 20 r10 register 10 (sl)
+ * 21 r11 register 11 (fp)
+ * 22 r12 register 12 (ip)
+ * 23 r13 register 13 (sp)
+ * 24 r14 register 14 (lr)
+ * 25 signal mask (dependant on magic)
+ * 26 (con't)
+ * 27 (con't)
+ * 28 (con't)
+ *
+ * The magic number number identifies the jmp_buf and
+ * how the buffer was created as well as providing
+ * a sanity check
+ *
+ * A side note I should mention - Please do not tamper
+ * with the floating point fields. While they are
+ * always saved and restored at the moment this cannot
+ * be garenteed especially if the compiler happens
+ * to be generating soft-float code so no fp
+ * registers will be used.
+ *
+ * Whilst this can be seen an encouraging people to
+ * use the setjmp buffer in this way I think that it
+ * is for the best then if changes occur compiles will
+ * break rather than just having new builds falling over
+ * mysteriously.
+ */
+
+#define _JB_MAGIC__SETJMP 0x4278f500
+#define _JB_MAGIC_SETJMP 0x4278f501
+
+/* Valid for all jmp_buf's */
+
+#define _JB_MAGIC 0
+#define _JB_REG_F4 1
+#define _JB_REG_F5 4
+#define _JB_REG_F6 7
+#define _JB_REG_F7 10
+#define _JB_REG_FPSR 13
+#define _JB_REG_R4 14
+#define _JB_REG_R5 15
+#define _JB_REG_R6 16
+#define _JB_REG_R7 17
+#define _JB_REG_R8 18
+#define _JB_REG_R9 19
+#define _JB_REG_R10 20
+#define _JB_REG_R11 21
+#define _JB_REG_R12 22
+#define _JB_REG_R13 23
+#define _JB_REG_R14 24
+
+/* Only valid with the _JB_MAGIC_SETJMP magic */
+
+#define _JB_SIGMASK 25