From e6ee7d3d4ae9cca5c6c22dfd0f83a734ba37e40b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Josef=20S=C3=B6ntgen?= <josef.soentgen@genode-labs.com>
Date: Fri, 10 Mar 2023 16:53:01 +0100
Subject: [PATCH] wifi: provide platform specific DTB access

The device-tree binary is normally required on ARM-based platforms
where as on x86 it is omitted. The platform-specific DTB helper
provides a generic interface for accssing the DTB and needs to be
implemented on each platform.

Issue #4813
---
 repos/pc/lib/mk/wifi.inc            |  1 +
 repos/pc/src/lib/wifi/dtb_helper.cc | 21 ++++++++++++++++++++
 repos/pc/src/lib/wifi/dtb_helper.h  | 30 +++++++++++++++++++++++++++++
 repos/pc/src/lib/wifi/wlan.cc       |  5 ++++-
 4 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 repos/pc/src/lib/wifi/dtb_helper.cc
 create mode 100644 repos/pc/src/lib/wifi/dtb_helper.h

diff --git a/repos/pc/lib/mk/wifi.inc b/repos/pc/lib/mk/wifi.inc
index d0e71ba1a5..a7b98e2d7b 100644
--- a/repos/pc/lib/mk/wifi.inc
+++ b/repos/pc/lib/mk/wifi.inc
@@ -12,6 +12,7 @@ SRC_CC  += wlan.cc
 SRC_CC  += firmware.cc
 SRC_CC  += socket_call.cc
 SRC_CC  += lx_emul/random.cc
+SRC_CC  += dtb_helper.cc
 
 SRC_C   += dummies.c
 SRC_C   += lx_emul.c
diff --git a/repos/pc/src/lib/wifi/dtb_helper.cc b/repos/pc/src/lib/wifi/dtb_helper.cc
new file mode 100644
index 0000000000..c298f86941
--- /dev/null
+++ b/repos/pc/src/lib/wifi/dtb_helper.cc
@@ -0,0 +1,21 @@
+/**
+ * \brief  DTB access helper
+ * \author Josef Soentgen
+ * \date   2023-04-11
+ */
+
+/*
+ * Copyright (C) 2023 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
+
+#include "dtb_helper.h"
+
+
+Dtb_helper::Dtb_helper(Genode::Env &env) : _env { env } { }
+
+
+void *Dtb_helper::dtb_ptr() { return nullptr; }
diff --git a/repos/pc/src/lib/wifi/dtb_helper.h b/repos/pc/src/lib/wifi/dtb_helper.h
new file mode 100644
index 0000000000..fd25cb4362
--- /dev/null
+++ b/repos/pc/src/lib/wifi/dtb_helper.h
@@ -0,0 +1,30 @@
+/**
+ * \brief  DTB access helper
+ * \author Josef Soentgen
+ * \date   2023-04-11
+ */
+
+/*
+ * Copyright (C) 2023 Genode Labs GmbH
+ *
+ * This file is distributed under the terms of the GNU General Public License
+ * version 2.
+ */
+
+#ifndef _DTB_HELPER_H_
+#define _DTB_HELPER_H_
+
+/* Genode includes */
+#include <base/env.h>
+
+
+struct Dtb_helper
+{
+	Genode::Env &_env;
+
+	Dtb_helper(Genode::Env &env);
+
+	void *dtb_ptr();
+};
+
+#endif /* _DTB_HELPER_H_ */
diff --git a/repos/pc/src/lib/wifi/wlan.cc b/repos/pc/src/lib/wifi/wlan.cc
index 5b2e8c47c0..d3e6d0b893 100644
--- a/repos/pc/src/lib/wifi/wlan.cc
+++ b/repos/pc/src/lib/wifi/wlan.cc
@@ -29,6 +29,7 @@
 
 /* local includes */
 #include "lx_user.h"
+#include "dtb_helper.h"
 
 using namespace Genode;
 
@@ -155,6 +156,8 @@ struct Wlan
 	Io_signal_handler<Wlan> _signal_handler { _env.ep(), *this,
 	                                          &Wlan::_handle_signal };
 
+	Dtb_helper _dtb_helper { _env };
+
 	void _handle_signal()
 	{
 		if (uplink_task_struct_ptr) {
@@ -175,7 +178,7 @@ struct Wlan
 		                   genode_allocator_ptr(Lx_kit::env().heap),
 		                   genode_signal_handler_ptr(_signal_handler));
 
-		lx_emul_start_kernel(nullptr);
+		lx_emul_start_kernel(_dtb_helper.dtb_ptr());
 	}
 };