Simulator: Adds necessary functionality to build Simulator under ARM Linux. Tested only on Raspberry3. Currently setjmp/longjmp do not save/restore floating point registers. Patch provided by Bitbucket user nbkolchin.

arch/sim/Kconfig

@@ -16,6 +16,9 @@ config HOST_X86_64
 config HOST_X86
 	bool "x86"
 
+config HOST_ARM
+  bool "arm"
+
 endchoice # Host CPU Type
 
 config SIM_M32

arch/sim/include/irq.h

@@ -57,10 +57,12 @@
    /* Storage order: %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15, %rip */
 
 #  define XCPTCONTEXT_REGS    8
-#else
+#elif defined(CONFIG_HOST_X86) || defined(CONFIG_SIM_M32)
    /* Storage order: %ebx, %esi, %edi, %ebp, sp, and return PC */
 
 #  define XCPTCONTEXT_REGS    6
+#elif defined(CONFIG_HOST_ARM)
+#  define XCPTCONTEXT_REGS 16
 #endif
 
 /****************************************************************************

arch/sim/src/up_internal.h

@@ -132,7 +132,7 @@
 #  define JB_SP    JB_RSP
 #  define JB_PC    JB_RSI
 
-#else
+#elif defined(CONFIG_HOST_X86) || defined(CONFIG_SIM_M32)
 /* Storage order: %ebx, $esi, %edi, %ebp, sp, and return PC */
 
 #  ifdef __ASSEMBLY__
@@ -152,7 +152,10 @@
 #    define JB_PC  (5)
 
 #  endif /* __ASSEMBLY__ */
-#endif /* CONFIG_HOST_X86_64 && !CONFIG_SIM_M32 */
+#elif defined(CONFIG_HOST_ARM)
+#  define JB_SP 8
+#  define JB_PC 9
+#endif
 
 /* Simulated Heap Definitions **********************************************/
 /* Size of the simulated heap */

arch/sim/src/up_setjmp_arm.S

@@ -0,0 +1,103 @@
+/****************************************************************************
+ * arch/sim/src/up_setjmp_arm.h
+ *
+ *   Copyright (C) 2017 Gregory Nutt. All rights reserved.
+ *
+ * Extracted from the MUSL C-library by Bitbucket user nbkolchin.  The MUSL
+ * C library has a compatible MIT license and is released here under the
+ * NuttX 3-clause BSD license:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+.syntax unified
+.global up_setjmp
+.type up_setjmp,%function
+up_setjmp:
+	mov ip,r0
+	stmia ip!,{v1,v2,v3,v4,v5,v6,sl,fp}
+	mov r2,sp
+	stmia ip!,{r2,lr}
+	mov r0,#0
+
+#if 0
+	adr r1,1f
+	ldr r2,1f
+	ldr r1,[r1,r2]
+
+	tst r1,#0x260
+	beq 3f
+	tst r1,#0x20
+	beq 2f
+	stc p2, cr4, [ip], #48
+2:	tst r1,#0x40
+	beq 2f
+	.fpu vfp
+	vstmia ip!, {d8-d15}
+	.fpu softvfp
+	.eabi_attribute 10, 0
+	.eabi_attribute 27, 0
+2:	tst r1,#0x200
+	beq 3f
+	stcl p1, cr10, [ip], #8
+	stcl p1, cr11, [ip], #8
+	stcl p1, cr12, [ip], #8
+	stcl p1, cr13, [ip], #8
+	stcl p1, cr14, [ip], #8
+	stcl p1, cr15, [ip], #8
+#endif
+3:	bx lr
+
+.syntax unified
+.global up_longjmp
+.type up_longjmp,%function
+up_longjmp:
+	mov ip,r0
+	movs r0,r1
+	moveq r0,#1
+	ldmia ip!, {v1,v2,v3,v4,v5,v6,sl,fp}
+	ldmia ip!, {r2,lr}
+	mov sp,r2
+
+#if 0
+	.fpu vfp
+	vldmia ip!, {d8-d15}
+	.fpu softvfp
+	.eabi_attribute 10, 0
+	.eabi_attribute 27, 0
+2:	tst r1,#0x200
+	beq 3f
+	ldcl p1, cr10, [ip], #8
+	ldcl p1, cr11, [ip], #8
+	ldcl p1, cr12, [ip], #8
+	ldcl p1, cr13, [ip], #8
+	ldcl p1, cr14, [ip], #8
+	ldcl p1, cr15, [ip], #8
+#endif
+3:	bx lr