[PATCH] Implement our own functions to convert between host and network values

[Flavio Cruz]

We add htonl, ntohl and ntohs which were the last symbols we relied on
from libc.

The Makefile.am file was updated to reflect the fact that we only require 
libgcc.
---
 Makefile.am      | 20 ++++++++------------
 Makefrag.am      |  4 +++-
 util/byteorder.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 util/byteorder.h | 31 +++++++++++++++++++++++++++++++
 4 files changed, 87 insertions(+), 13 deletions(-)
 create mode 100644 util/byteorder.c
 create mode 100644 util/byteorder.h

diff --git a/Makefile.am b/Makefile.am
index 33f770f6..0b7ebc56 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -167,31 +167,27 @@ gnumach_o_LINK = $(LD) $(LDFLAGS) -u _start -r -o $@
 noinst_PROGRAMS += \
        gnumach.o
 
-# This is the list of routines we decide is OK to steal from the C library or 
libgcc.
-clib_routines := htonl htons ntohl ntohs                       \
-                udivdi3 __udivdi3 __udivmoddi4 __umoddi3       \
-                __divdi3 __moddi3                              \
-                __rel_iplt_start __rel_iplt_end                \
-                __rela_iplt_start __rela_iplt_end              \
-                __ffsdi2                                       \
-                _START _start etext _edata end _end # actually ld magic, not 
libc.
+# This is the list of routines we use from libgcc.
+libgcc_routines := __udivmoddi4 __umoddi3 __ffsdi2
+# References generated by ld.
+ld_magic_routines := __rel_iplt_start __rel_iplt_end etext _edata _end
 gnumach-undef: gnumach.$(OBJEXT)
        $(NM_V) $(NM) -u $< | sed 's/  *U  *//' | sort -u > $@
 MOSTLYCLEANFILES += gnumach-undef
 gnumach-undef-bad: gnumach-undef Makefile
-       $(AM_V_GEN) sed '$(foreach r,$(clib_routines),/^$r$$/d;)' $< > $@
+       $(AM_V_GEN) sed '$(foreach r,$(libgcc_routines) 
$(ld_magic_routines),/^$r$$/d;)' $< > $@
 MOSTLYCLEANFILES += gnumach-undef-bad
-clib-routines.o: gnumach-undef gnumach-undef-bad
+libgcc-routines.o: gnumach-undef gnumach-undef-bad
        $(AM_V_at) if test -s gnumach-undef-bad; \
        then cat gnumach-undef-bad; exit 2; else true; fi
        $(AM_V_CCLD) $(CCLD) $(LDFLAGS) -nostdlib -nostartfiles -r -static \
-         -o $@ `sed 's/^/-Wl,-u,/' < $<` -x c /dev/null -lc -lgcc
+         -o $@ `sed 's/^/-Wl,-u,/' < $<` -x c /dev/null -lgcc
        @if nm $@ | grep __init_cpu_features; \
        then echo "Please install a 32bit libc without multiarch support (on 
Debian systems, the libc6-dev:i386 package containing 
/usr/lib/i386-linux-gnu/libc.a)". ; \
        false ; fi
 
 gnumach_LINK = $(LD) $(LDFLAGS) $(LINKFLAGS) $(gnumach_LINKFLAGS) -o $@
-gnumach_LDADD = gnumach.o clib-routines.o
+gnumach_LDADD = gnumach.o libgcc-routines.o
 
 #
 # Installation.
diff --git a/Makefrag.am b/Makefrag.am
index 51b15260..e2593c42 100644
--- a/Makefrag.am
+++ b/Makefrag.am
@@ -244,7 +244,9 @@ libkernel_a_SOURCES += \
        util/putchar.h \
        util/puts.c \
        util/atoi.c \
-       util/atoi.h
+       util/atoi.h \
+       util/byteorder.h \
+       util/byteorder.c
 
 #
 # Virtual memory implementation.
diff --git a/util/byteorder.c b/util/byteorder.c
new file mode 100644
index 00000000..18311972
--- /dev/null
+++ b/util/byteorder.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Mach.
+ *
+ * GNU Mach is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "util/byteorder.h"
+
+uint16_t ntohs(uint16_t netshort) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+       return __builtin_bswap16(netshort);
+#else
+       return netshort;
+#endif
+}
+
+uint32_t ntohl(uint32_t netlong) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+       return __builtin_bswap32(netlong);
+#else
+       return netlong;
+#endif
+}
+
+uint32_t htonl(uint32_t hostlong) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+       return __builtin_bswap32(hostlong);
+#else
+       return hostlong;
+#endif
+}
diff --git a/util/byteorder.h b/util/byteorder.h
new file mode 100644
index 00000000..2b780ffe
--- /dev/null
+++ b/util/byteorder.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Mach.
+ *
+ * GNU Mach is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any later
+ * version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef _UTIL_BYTEORDER_H_
+#define _UTIL_BYTEORDER_H_
+
+#include <stdint.h>
+
+uint16_t ntohs(uint16_t netshort);
+uint32_t ntohl(uint32_t netlong);
+
+uint32_t htonl(uint32_t hostlong);
+
+#endif /* _UTIL_BYTEORDER_H_ */
-- 
2.37.2