Re: Arm semihosting v2 implementation isn't complete

I suggest following patch:

On Tue, Dec 18, 2018 at 5:12 PM Alexander Fedotov <[email protected]> wrote:
>
> Hi Tamar
>
> I see HLT only in comments, not in defines:
>
> #ifdef THUMB_VXM
>   #define AngelSWIInsn            "bkpt"
>   #define AngelSWIAsm            bkpt
> #else
>   #define AngelSWIInsn            "swi"
>   #define AngelSWIAsm            swi
> #endif
>
>
> On Tue, Dec 18, 2018 at 4:50 PM Tamar Christina <[email protected]> wrote:
> >
> > Hi Alex
> >
> > > -----Original Message-----
> > > From: [email protected] <[email protected]> On
> > > Behalf Of Alexander Fedotov
> > > Sent: Tuesday, December 18, 2018 13:08
> > > To: Newlib <[email protected]>
> > > Subject: Arm semihosting v2 implementation isn't complete
> > >
> > > Hi all
> > >
> > > I see that number of commits were dedicated to changes for Arm
> > > Semihosting v2 specification that states:
> > > ARM encourages semihosting callers to implement support for trapping using
> > > HLT on A32 and T32 as a configurable option. ARM strongly discourages
> > > semihosting callers from mixing the HLT and SVC mechanisms within the
> > > same executable.
> > >
> > > At the moment there is no HLT instruction used in libgloss/arm.
> >
> > There is, see swi.h, we don't support mixing of HLT and SVC (as mentioned in the specification bit you quoted) so they are in different libraries.
> > HLT is used when you used the MIXED_MODE spec files. E.g. aprofile-validation-v2m.specs will use HLT and aprofile-validation.specs uses SVC.
> >
> > Regards,
> > Tamar
> >
> > >
> > > So the question is: is there any reason to not have HLT right now ?
> > >
> > > Alex
>
>
>
> --
> Best regards,
> AF



-- 
Best regards,
AF

From 2b3cce5b1bf23a45a0efd33122cadd6ce18260b9 Mon Sep 17 00:00:00 2001
From: Alexander Fedotov <[email protected]>
Date: Tue, 18 Dec 2018 09:06:55 -0600
Subject: [PATCH] Use HLT instruction for ARMv8 according to Arm Semihosting v2
 specification.

---
 libgloss/arm/swi.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libgloss/arm/swi.h b/libgloss/arm/swi.h
index 67eb36b3f..ac3295c8b 100644
--- a/libgloss/arm/swi.h
+++ b/libgloss/arm/swi.h
@@ -50,6 +50,9 @@
 #ifdef THUMB_VXM
   #define AngelSWIInsn			"bkpt"
   #define AngelSWIAsm			bkpt
+#elif defined (SEMIHOST_V2) && (__ARM_ARCH == 8)
+  #define AngelSWIInsn			"hlt"
+  #define AngelSWIAsm			hlt
 #else
   #define AngelSWIInsn			"swi"
   #define AngelSWIAsm			swi
-- 
2.17.1