From fcb9abccbbc73a4f449d55c2c7fb369db2ad139d Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Wed, 8 Jul 2015 02:13:16 +0200
Subject: [PATCH] 5e: enable VFP emulation by default, doubles only need to be
 4 byte aligned

this adds -F flag to 5e (same as 5l) to disable VFP emulation
and makes VFP emulation the default.
---
 sys/man/1/5e         | 12 ++++--------
 sys/src/cmd/5e/5e.c  |  4 +++-
 sys/src/cmd/5e/vfp.c |  2 +-
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/sys/man/1/5e b/sys/man/1/5e
index 45adbd629..9c9cb1793 100644
--- a/sys/man/1/5e
+++ b/sys/man/1/5e
@@ -4,7 +4,7 @@
 .SH SYNOPSIS
 .B 5e
 [
-.B -npb
+.B -npbF
 ]
 .I text
 [
@@ -92,6 +92,9 @@ causes failing processes to call
 instead of
 .I sysfatal.
 See below.
+.TP
+.B -F
+Disable emulation of VFP floating point instructions.
 .SH SOURCE
 .B /sys/src/cmd/5e
 .SH SEE ALSO
@@ -108,13 +111,6 @@ The emulator does not post
 notes.
 
 Obscure opcodes, in particular uncommon operations on R15, are not implemented.
-Careless use of the
-.B LDREX
-and
-.B STREX
-instructions can lead to deadlock, while the
-.I ARM Architecture Reference Manual
-indicates a real processor will exhibit undefined behavior in these cases.
 
 Accesses spanning segment boundaries will be treated as page faults.
 Many syscalls such as
diff --git a/sys/src/cmd/5e/5e.c b/sys/src/cmd/5e/5e.c
index 238bcadaa..85367c3ee 100644
--- a/sys/src/cmd/5e/5e.c
+++ b/sys/src/cmd/5e/5e.c
@@ -4,6 +4,7 @@
 #include "dat.h"
 #include "fns.h"
 
+int vfp = 1;
 int nflag, pflag, bflag;
 Ref nproc;
 
@@ -49,7 +50,7 @@ cleanup(void)
 static void
 usage(void)
 {
-	fprint(2, "usage: 5e [-npbf] text [...]\n");
+	fprint(2, "usage: 5e [-npbF] text [...]\n");
 	exits(nil);
 }
 
@@ -105,6 +106,7 @@ main(int argc, char **argv)
 	case 'p': pflag++; break;
 	case 'b': bflag++; break;
 	case 'f': vfp = 1; break;
+	case 'F': vfp = 0; break;
 	default: usage();
 	} ARGEND;
 	if(argc < 1)
diff --git a/sys/src/cmd/5e/vfp.c b/sys/src/cmd/5e/vfp.c
index 2ab755a09..0f4e7eeb6 100644
--- a/sys/src/cmd/5e/vfp.c
+++ b/sys/src/cmd/5e/vfp.c
@@ -55,7 +55,7 @@ vfprmtransfer(u32int instr)
 	sz = instr & (1<<8);
 	if((instr & (1<<23)) == 0)
 		off = -off;
-	ea = vaddr(evenaddr(P->R[n] + off, sz ? 7 : 3), 8, &seg);
+	ea = vaddr(evenaddr(P->R[n] + off, 3), sz ? 8 : 4, &seg);
 	switch((instr>>20)&0x3){
 	case 0:
 		if(sz)