# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1527543865 -7200
# Node ID 4087e1c2b12a29c0e738ce0032c1a770f299a1de
# Parent  86ad5faff7f2195c71e0c9507be1ced7f79b17fd
Added utilities for dynamic library loading.

diff -r 86ad5faff7f2 -r 4087e1c2b12a pkg/devices/util/include/dl.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pkg/devices/util/include/dl.h	Mon May 28 23:44:25 2018 +0200
@@ -0,0 +1,30 @@
+/*
+ * Dynamic loading support.
+ *
+ * Copyright (C) 2018 Paul Boddie <paul@boddie.org.uk>
+ *
+ * This program 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 of
+ * the License, 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
+ */
+
+#pragma once
+
+#include <l4/sys/types.h>
+
+EXTERN_C_BEGIN
+
+void *load_function(const char *filename, const char *function);
+
+EXTERN_C_END
diff -r 86ad5faff7f2 -r 4087e1c2b12a pkg/devices/util/src/Makefile
--- a/pkg/devices/util/src/Makefile	Sun May 27 22:08:58 2018 +0200
+++ b/pkg/devices/util/src/Makefile	Mon May 28 23:44:25 2018 +0200
@@ -4,10 +4,10 @@
 TARGET		= libdevice_util.o.a
 PC_FILENAME	:= libdevice-util
 
-SRC_CC		:= dataspace.cc event-loop.cc memory.cc
+SRC_CC		:= dataspace.cc dl.cc event-loop.cc memory.cc
 
 PRIVATE_INCDIR	+= $(PKGDIR)/util/include
 
-REQUIRES_LIBS	:= libio l4re_c l4re_c-util
+REQUIRES_LIBS	:= libio l4re_c l4re_c-util libdl
 
 include $(L4DIR)/mk/lib.mk
diff -r 86ad5faff7f2 -r 4087e1c2b12a pkg/devices/util/src/dl.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pkg/devices/util/src/dl.cc	Mon May 28 23:44:25 2018 +0200
@@ -0,0 +1,50 @@
+/*
+ * Dynamic loading support.
+ *
+ * (c) 2018 Paul Boddie <paul@boddie.org.uk>
+ *
+ * This program 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 of
+ * the License, 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 <l4/devices/dl.h>
+#include <dlfcn.h>
+#include <stdio.h>
+
+void *load_function(const char *filename, const char *function)
+{
+  char libname[64];
+  FILE *f = fopen(filename, "r");
+  size_t nread;
+  void *handle;
+
+  /* Obtain the library name from the file. */
+
+  if (f == NULL) return 0;
+
+  nread = fread(libname, sizeof(char), 63, f);
+  fclose(f);
+
+  if (ferror(f)) return 0;
+
+  libname[nread] = '\0';
+
+  /* Obtain the linked data. */
+
+  handle = dlopen(libname, RTLD_NOW);
+  if (handle == NULL) return 0;
+
+  return dlsym(handle, function);
+}