[newlib-cygwin] Don't fetch command line options without semi-hosting

[newlib-cygwin] Don't fetch command line options without semi-hosting

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=32ca315312628dfce2f0e1c74eab1db33a5f0061

commit 32ca315312628dfce2f0e1c74eab1db33a5f0061
Author: Yao Qi <qiyaoltc@gmail.com>
Date:   Wed Aug 9 15:37:57 2017 +0100

    Don't fetch command line options without semi-hosting
    
    Nowadays, the code fetching command line options via semi-hosting are
    unconditionally pulled in, so that the semi-hosting code is still
    there even I compile with option --specs=nosys.specs.
    
    gdb ./aarch64-none-elf/libgloss/aarch64/crt0.o
    
    (gdb) disassemble _start
    
       0x0000000000000050 <+80>:	ldr	x1, 0x128 <_cpu_init_hook+48>
       0x0000000000000054 <+84>:	mov	w0, #0x15
       0x0000000000000058 <+88>:	hlt	#0xf000
    
    This patch fixes this problem by wrapping the code by ARM_RDI_MONITOR.
    When semi-hosting is not used, set command line options to NULL.

Diff:
---
 libgloss/aarch64/crt0.S | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libgloss/aarch64/crt0.S b/libgloss/aarch64/crt0.S
index cbff11a..3bf0278 100644
--- a/libgloss/aarch64/crt0.S
+++ b/libgloss/aarch64/crt0.S
@@ -157,6 +157,7 @@
 
 	bl	FUNCTION (_init)
 
+#ifdef ARM_RDI_MONITOR
 	/* Fetch and parse the command line.  */
 	ldr	x1, .Lcmdline		/* Command line descriptor.  */
 	mov	w0, #AngelSVC_Reason_GetCmdLine
@@ -219,6 +220,11 @@
 	and	x4, x1, ~15
 	mov	sp, x4
 
+#else
+	mov	x0, #0	/* argc = 0 */
+	mov	x1, #0	/* argv = NULL */
+#endif
+
 	bl	FUNCTION (main)
 
 	b	FUNCTION (exit)		/* Cannot return.  */