diff --git a/repos/dde_rump/include/rump/bootstrap.h b/repos/dde_rump/include/rump/bootstrap.h
deleted file mode 100644
index 2279eff890..0000000000
--- a/repos/dde_rump/include/rump/bootstrap.h
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * \brief  Rump initialization
- * \author Norman Feske
- * \date   2016-11-02
- */
-
-/*
- * Copyright (C) 2016 Genode Labs GmbH
- *
- * This file is part of the Genode OS framework, which is distributed
- * under the terms of the GNU General Public License version 2.
- */
-#ifndef _INCLUDE__RUMP__BOOTSTRAP_H_
-#define _INCLUDE__RUMP__BOOTSTRAP_H_
-
-#include <base/env.h>
-#include <base/allocator.h>
-
-void rump_bootstrap_init(Genode::Env &env, Genode::Allocator &heap);
-
-#endif /* _INCLUDE__RUMP__BOOTSTRAP_H_ */
diff --git a/repos/dde_rump/include/rump/env.h b/repos/dde_rump/include/rump/env.h
new file mode 100644
index 0000000000..837c8d0b6b
--- /dev/null
+++ b/repos/dde_rump/include/rump/env.h
@@ -0,0 +1,47 @@
+/*
+ * \brief  Helper class to make the Genode Env globally available
+ * \author Sebastian Sumpf
+ * \date   2016-06-21
+ */
+
+/*
+ * Copyright (C) 2016 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _INCLUDE__RUMP__ENV_H_
+#define _INCLUDE__RUMP__ENV_H_
+
+#include <base/attached_rom_dataspace.h>
+#include <base/env.h>
+#include <base/heap.h>
+#include <util/reconstructible.h>
+
+namespace Rump {
+	class Env;
+
+	Env &env();
+
+	void construct_env(Genode::Env &env);
+}
+
+class Rump::Env
+{
+	private:
+
+		Genode::Env                   &_env;
+		Genode::Heap                   _heap { _env.ram(), _env.rm() };
+		Genode::Attached_rom_dataspace _config { _env, "config" };
+
+	public:
+
+		Env(Genode::Env &env) : _env(env) { }
+
+		Genode::Env                    &env()        { return _env; }
+		Genode::Heap                   &heap()       { return _heap; }
+		Genode::Attached_rom_dataspace &config_rom() { return _config; }
+};
+
+#endif /* _INCLUDE__RUMP__ENV_H_ */
diff --git a/repos/dde_rump/include/rump_fs/fs.h b/repos/dde_rump/include/rump_fs/fs.h
index 8af07a44a5..16e6381852 100644
--- a/repos/dde_rump/include/rump_fs/fs.h
+++ b/repos/dde_rump/include/rump_fs/fs.h
@@ -24,6 +24,8 @@
 #define GENODE_DEVICE        "/genode"
 
 
+void rump_io_backend_init();
+
 /**
  * Sync I/O back-end with underlying Genode subsystems
  */
diff --git a/repos/dde_rump/include/util/allocator_fap.h b/repos/dde_rump/include/util/allocator_fap.h
index cea6f34d90..a33b4a88e2 100644
--- a/repos/dde_rump/include/util/allocator_fap.h
+++ b/repos/dde_rump/include/util/allocator_fap.h
@@ -18,7 +18,7 @@
 #include <dataspace/client.h>
 #include <rm_session/connection.h>
 #include <region_map/client.h>
-
+#include <rump/env.h>
 
 namespace Allocator {
 	template <unsigned VM_SIZE, typename POLICY> class Backend_alloc;
@@ -85,7 +85,7 @@ namespace Allocator {
 				Policy_guard<POLICY> guard;
 
 				try {
-					_ds_cap[_index] =  Genode::env()->ram_session()->alloc(BLOCK_SIZE, _cached);
+					_ds_cap[_index] =  Rump::env().env().ram().alloc(BLOCK_SIZE, _cached);
 					/* attach at index * BLOCK_SIZE */
 					Region_map_client::attach_at(_ds_cap[_index], _index * BLOCK_SIZE, BLOCK_SIZE, 0);
 					/* lookup phys. address */
@@ -114,10 +114,10 @@ namespace Allocator {
 			:
 				Region_map_client(Rm_connection::create(VM_SIZE)),
 				_cached(cached),
-				_range(Genode::env()->heap())
+				_range(&Rump::env().heap())
 			{
 				/* reserver attach us, anywere */
-				_base = Genode::env()->rm_session()->attach(dataspace());
+				_base = Rump::env().env().rm().attach(dataspace());
 			}
 
 			/**
diff --git a/repos/dde_rump/include/util/hard_context.h b/repos/dde_rump/include/util/hard_context.h
index c680c33431..0575ae20b3 100644
--- a/repos/dde_rump/include/util/hard_context.h
+++ b/repos/dde_rump/include/util/hard_context.h
@@ -22,6 +22,8 @@ extern "C" {
 
 #include <base/thread.h>
 #include <base/log.h>
+#include <rump/env.h>
+#include <util/avl_tree.h>
 
 
 /*************
@@ -35,12 +37,17 @@ namespace Timer {
 };
 
 
-class Hard_context
+class Hard_context : public Genode::Avl_node<Hard_context>
 {
 	private:
 
 		int  _cookie;
-		lwp *_lwp     = 0;
+		lwp *_lwp     = nullptr;
+
+
+	public:
+
+		Genode::Thread *_myself = nullptr;
 
 	public:
 
@@ -50,12 +57,65 @@ class Hard_context
 		void set_lwp(lwp *l) { _lwp = l; }
 		lwp *get_lwp() { return _lwp; }
 
-		static Timer::Connection *timer();
+		static Timer::Connection &timer();
+
+		bool higher(Hard_context *h) { return _myself > h->_myself; }
+
+		Hard_context *find(Genode::Thread const *t)
+		{
+			if (_myself == t)
+				return this;
+
+			Hard_context *h = child(_myself > t);
+			if (!h)
+				return nullptr;
+
+			return h->find(t);
+		}
+
+		void thread(Genode::Thread *t) { _myself = t; }
+};
+
+
+class Hard_context_registry : public Genode::Avl_tree<Hard_context>
+{
+	private:
+
+		Genode::Lock lock;
+
+	public:
+
+		Hard_context *find(Genode::Thread const *t)
+		{
+			Genode::Lock::Guard g(lock);
+			if (!first())
+				return nullptr;
+
+			return first()->find(t);
+		}
+
+		void insert(Hard_context *h)
+		{
+			Genode::Lock::Guard g(lock);
+			Avl_tree::insert(h);
+		}
+
+		void remove(Hard_context *h)
+		{
+			Genode::Lock::Guard g(lock);
+			Avl_tree::remove(h);
+		}
+
+		static Hard_context_registry &r()
+		{
+			static Hard_context_registry _r;
+			return _r;
+		}
 };
 
 
 class Hard_context_thread : public Hard_context,
-                            public Genode::Thread_deprecated<sizeof(Genode::addr_t) * 2048>
+                            public Genode::Thread
 {
 	private:
 
@@ -66,14 +126,17 @@ class Hard_context_thread : public Hard_context,
 
 		void entry()
 		{
+			Hard_context::thread(Genode::Thread::myself());
+			Hard_context_registry::r().insert(this);
 			_func(_arg);
+			Hard_context_registry::r().remove(this);
 			Genode::log(__func__, " returned from func");
 		}
 
 	public:
 
 		Hard_context_thread(char const *name, func f, void *arg, int cookie, bool run = true)
-		: Hard_context(cookie), Thread_deprecated(name),
+		: Hard_context(cookie), Thread(Rump::env().env(), name, sizeof(long) * 2048),
 			_func(f), _arg(arg) { if (run) start(); }
 };
 
diff --git a/repos/dde_rump/lib/mk/rump_base.inc b/repos/dde_rump/lib/mk/rump_base.inc
index 6a6727b6b2..e47932eb3a 100644
--- a/repos/dde_rump/lib/mk/rump_base.inc
+++ b/repos/dde_rump/lib/mk/rump_base.inc
@@ -15,7 +15,7 @@ VERBOSE_LEVEL ?= 0
 #
 # Sources
 #
-SRC_CC = dummies.cc hypercall.cc bootstrap.cc io.cc sync.cc misc.cc
+SRC_CC = dummies.cc hypercall.cc bootstrap.cc io.cc sync.cc misc.cc env.cc
 
 #
 # TARGET to trigger rump build
diff --git a/repos/dde_rump/run/rump_ext2.run b/repos/dde_rump/run/rump_ext2.run
index e1c33296f2..b958397a33 100644
--- a/repos/dde_rump/run/rump_ext2.run
+++ b/repos/dde_rump/run/rump_ext2.run
@@ -85,7 +85,7 @@ install_config $config
 set boot_modules {
 	core ld.lib.so init timer test-libc_vfs ram_blk
 	rump.lib.so rump_fs.lib.so rump_fs
-	ext2.raw libc.lib.so
+	ext2.raw libc.lib.so libm.lib.so
 }
 
 build_boot_image $boot_modules
diff --git a/repos/dde_rump/src/lib/rump/bootstrap.cc b/repos/dde_rump/src/lib/rump/bootstrap.cc
index 38b074fa6c..64122e6964 100644
--- a/repos/dde_rump/src/lib/rump/bootstrap.cc
+++ b/repos/dde_rump/src/lib/rump/bootstrap.cc
@@ -17,11 +17,13 @@ extern "C" {
 #include <elf.h>
 }
 
-#include <rump/bootstrap.h>
+#include <rump/env.h>
+
 #include <base/log.h>
 #include <base/shared_object.h>
 #include <util/string.h>
 
+
 extern "C" void wait_for_continue();
 
 #ifdef _LP64
@@ -36,46 +38,20 @@ static bool const verbose = false;
 
 
 static Genode::Shared_object *obj_main;
-static Genode::Env           *env_ptr;
-static Genode::Allocator     *heap_ptr;
-
-
-void rump_bootstrap_init(Genode::Env &env, Genode::Allocator &alloc)
-{
-	/* ignore subsequent calls */
-	if (env_ptr)
-		return;
-
-	env_ptr  = &env;
-	heap_ptr = &alloc;
-}
-
-
-/**
- * Exception type
- */
-class Missing_call_of_rump_bootstrap_init { };
 
 
 static Genode::Env &env()
 {
-	if (!env_ptr)
-		throw Missing_call_of_rump_bootstrap_init();
-
-	return *env_ptr;
+	return Rump::env().env();
 }
 
 
 static Genode::Allocator &heap()
 {
-	if (!heap_ptr)
-		throw Missing_call_of_rump_bootstrap_init();
-
-	return *heap_ptr;
+	return Rump::env().heap();
 }
 
 
-
 struct Sym_tab
 {
 	Genode::Shared_object::Link_map const *map;
@@ -119,7 +95,7 @@ struct Sym_tab
 	~Sym_tab()
 	{
 		if (sym_tab)
-			destroy(Genode::env()->heap(), sym_tab);
+			destroy(heap(), sym_tab);
 	}
 
 
@@ -186,7 +162,7 @@ struct Sym_tab
 
 	void alloc_memory()
 	{
-		sym_tab = (Elf_Sym *)Genode::env()->heap()->alloc(sizeof(Elf_Sym) * sym_cnt);
+		sym_tab = (Elf_Sym *)heap().alloc(sizeof(Elf_Sym) * sym_cnt);
 	}
 
 	void read_symbols()
diff --git a/repos/dde_rump/src/lib/rump/env.cc b/repos/dde_rump/src/lib/rump/env.cc
new file mode 100644
index 0000000000..0590059f35
--- /dev/null
+++ b/repos/dde_rump/src/lib/rump/env.cc
@@ -0,0 +1,31 @@
+/**
+ * \brief  Rump::Env initialization
+ * \author Sebastian Sumpf
+ * \date   2016-06-23
+ */
+
+/*
+ * Copyright (C) 2016 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#include <rump/env.h>
+
+/*
+ * Genode nviroment instance
+ */
+static Genode::Constructible<Rump::Env> _env;
+
+
+Rump::Env &Rump::env()
+{
+	return *_env;
+}
+
+
+void Rump::construct_env(Genode::Env &env)
+{
+	_env.construct(env);
+}
diff --git a/repos/dde_rump/src/lib/rump/hypercall.cc b/repos/dde_rump/src/lib/rump/hypercall.cc
index b34b17dede..e6a3b980f0 100644
--- a/repos/dde_rump/src/lib/rump/hypercall.cc
+++ b/repos/dde_rump/src/lib/rump/hypercall.cc
@@ -14,10 +14,10 @@
 
 #include "sched.h"
 
-#include <base/env.h>
 #include <base/log.h>
 #include <base/sleep.h>
 #include <os/timed_semaphore.h>
+#include <rump/env.h>
 #include <util/allocator_fap.h>
 #include <util/random.h>
 #include <util/string.h>
@@ -31,53 +31,32 @@ static bool verbose = false;
 struct rumpuser_hyperup _rump_upcalls;
 
 
-/********************
- ** Initialization **
- ********************/
-
-int rumpuser_init(int version, const struct rumpuser_hyperup *hyp)
-{
-	Genode::log("RUMP ver: ", version);
-	if (version != SUPPORTED_RUMP_VERSION) {
-		Genode::error("unsupported rump-kernel version (", version, ") - "
-		              "supported is ", (int)SUPPORTED_RUMP_VERSION);
-		return -1;
-	}
-
-	_rump_upcalls = *hyp;
-
-	/*
-	 * Start 'Timeout_thread' so it does not get constructed concurrently (which
-	 * causes one thread to spin in cxa_guard_aqcuire), making emulation *really*
-	 * slow
-	 */
-	Genode::Timeout_thread::alarm_timer();
-
-	return 0;
-}
-
-
 /*************
  ** Threads **
  *************/
 
-static Hard_context * main_thread()
+static Hard_context *main_context()
 {
 	static Hard_context inst(0);
 	return &inst;
 }
 
+
 static Hard_context *myself()
 {
-	Hard_context *h = dynamic_cast<Hard_context *>(Genode::Thread::myself());
-	return h ? h : main_thread();
+	Hard_context *h = Hard_context_registry::r().find(Genode::Thread::myself());
+
+	if (!h)
+		Genode::error("Hard context is nullptr (", Genode::Thread::myself(), ")");
+
+	return h;
 }
 
 
-Timer::Connection *Hard_context::timer()
+Timer::Connection &Hard_context::timer()
 {
-	static Timer::Connection _timer;
-	return &_timer;
+	static Timer::Connection _timer { Rump::env().env() };
+	return _timer;
 }
 
 
@@ -112,7 +91,7 @@ int rumpuser_thread_create(func f, void *arg, const char *name,
 	if (mustjoin)
 		*cookie = (void *)++count;
 
-	new (Genode::env()->heap()) Hard_context_thread(name, f, arg, mustjoin ? count : 0);
+	new (Rump::env().heap()) Hard_context_thread(name, f, arg, mustjoin ? count : 0);
 
 	return 0;
 }
@@ -128,6 +107,37 @@ int errno;
 void rumpuser_seterrno(int e) { errno = e; }
 
 
+/********************
+ ** Initialization **
+ ********************/
+
+int rumpuser_init(int version, const struct rumpuser_hyperup *hyp)
+{
+	Genode::log("RUMP ver: ", version);
+	if (version != SUPPORTED_RUMP_VERSION) {
+		Genode::error("unsupported rump-kernel version (", version, ") - "
+		              "supported is ", (int)SUPPORTED_RUMP_VERSION);
+		return -1;
+	}
+
+	_rump_upcalls = *hyp;
+
+	/* register context for main EP */
+	main_context()->thread(Genode::Thread::myself());
+	Hard_context_registry::r().insert(main_context());
+
+	/*
+	 * Start 'Timeout_thread' so it does not get constructed concurrently (which
+	 * causes one thread to spin in cxa_guard_aqcuire), making emulation *really*
+	 * slow
+	 */
+	Genode::Timeout_thread::alarm_timer();
+
+	return 0;
+}
+
+
+
 /*************************
  ** Parameter retrieval **
  *************************/
@@ -152,7 +162,7 @@ int rumpuser_getparam(const char *name, void *buf, size_t buflen)
 	if (!Genode::strcmp(name, "RUMP_MEMLIMIT")) {
 
 		/* leave 2 MB for the Genode */
-		size_t rump_ram =  Genode::env()->ram_session()->avail();
+		size_t rump_ram =  Rump::env().env().ram().avail();
 
 		if (rump_ram <= RESERVE_MEM) {
 			Genode::error("insufficient quota left: ",
@@ -178,20 +188,22 @@ int rumpuser_getparam(const char *name, void *buf, size_t buflen)
 
 void rumpuser_putchar(int ch)
 {
-	static unsigned char buf[256];
+	enum { BUF_SIZE = 256 };
+	static unsigned char buf[BUF_SIZE];
 	static int count = 0;
 
-	buf[count++] = (unsigned char)ch;
+	if (count < BUF_SIZE - 1 && ch != '\n')
+		buf[count++] = (unsigned char)ch;
 
-	if (ch == '\n') {
+	if (ch == '\n' || count == BUF_SIZE - 1) {
 		buf[count] = 0;
 		int nlocks;
-		if (myself() != main_thread())
+		if (myself() != main_context())
 			rumpkern_unsched(&nlocks, 0);
 
 		Genode::log("rump: ", Genode::Cstring((char const *)buf));
 
-		if (myself() != main_thread())
+		if (myself() != main_context())
 			rumpkern_sched(nlocks, 0);
 
 		count = 0;
@@ -209,14 +221,14 @@ struct Allocator_policy
 	{
 		int nlocks;
 
-		if (myself() != main_thread())
+		if (myself() != main_context())
 			rumpkern_unsched(&nlocks, 0);
 		return nlocks;
 	}
 
 	static void unblock(int nlocks)
 	{
-		if (myself() != main_thread())
+		if (myself() != main_context())
 			rumpkern_sched(nlocks, 0);
 	}
 };
@@ -230,12 +242,14 @@ static Genode::Lock & alloc_lock()
 	return inst;
 }
 
+
 static Rump_alloc* allocator()
 {
 	static Rump_alloc _fap(true);
 	return &_fap;
 }
 
+
 int rumpuser_malloc(size_t len, int alignment, void **memp)
 {
 	Genode::Lock::Guard guard(alloc_lock());
@@ -269,7 +283,7 @@ void rumpuser_free(void *mem, size_t len)
 int rumpuser_clock_gettime(int enum_rumpclock, int64_t *sec, long *nsec)
 {
 	Hard_context *h = myself();
-	unsigned long t = h->timer()->elapsed_ms();
+	unsigned long t = h->timer().elapsed_ms();
 	*sec = (int64_t)t / 1000;
 	*nsec = (t % 1000) * 1000;
 	return 0;
@@ -281,7 +295,7 @@ int rumpuser_clock_sleep(int enum_rumpclock, int64_t sec, long nsec)
 	int nlocks;
 	unsigned int msec = 0;
 
-	Timer::Connection *timer  = myself()->timer();
+	Timer::Connection &timer  = myself()->timer();
 
 	rumpkern_unsched(&nlocks, 0);
 	switch (enum_rumpclock) {
@@ -289,12 +303,12 @@ int rumpuser_clock_sleep(int enum_rumpclock, int64_t sec, long nsec)
 			msec = sec * 1000 + nsec / (1000*1000UL);
 			break;
 		case RUMPUSER_CLOCK_ABSMONO:
-			msec = timer->elapsed_ms();
+			msec = timer.elapsed_ms();
 			msec = ((sec * 1000) + (nsec / (1000 * 1000))) - msec;
 			break;
 	}
 
-	timer->msleep(msec);
+	timer.msleep(msec);
 	rumpkern_sched(nlocks, 0);
 	return 0;
 }
diff --git a/repos/dde_rump/src/lib/rump/io.cc b/repos/dde_rump/src/lib/rump/io.cc
index d445b8756a..5307f650af 100644
--- a/repos/dde_rump/src/lib/rump/io.cc
+++ b/repos/dde_rump/src/lib/rump/io.cc
@@ -1,5 +1,5 @@
 /**
- * \brief  Connect rump kernel Genode's block interface
+ * \brief  Connect rump kernel to Genode's block interface
  * \author Sebastian Sumpf
  * \date   2013-12-16
  */
@@ -13,218 +13,35 @@
 
 #include "sched.h"
 #include <base/allocator_avl.h>
-#include <base/thread.h>
 #include <base/printf.h>
 #include <block_session/connection.h>
+#include <rump/env.h>
 #include <rump_fs/fs.h>
-#include <util/list.h>
-#include <util/string.h>
 
 
 static const bool verbose = false;
 
 enum  { GENODE_FD = 64 };
 
-struct Packet : Genode::List<Packet>::Element
+/**
+ * Block session connection
+ */
+class Backend
 {
-	Block::sector_t                  blk;
-	Genode::size_t                   cnt;
-	Block::Packet_descriptor::Opcode opcode;
-	void                            *data;
-	long                             offset;
-	rump_biodone_fn                  biodone;
-	void                            *donearg;
-	bool                             valid;
-	bool                             pending;
-	bool                             sync;
-};
-
-
-class Backend : public Hard_context_thread
-{
-
 	private:
 
-		enum { COUNT = Block::Session::TX_QUEUE_SIZE };
-
-		Genode::Allocator_avl              _alloc;
-		Block::Connection                  _session;
+		Genode::Allocator_avl              _alloc { &Rump::env().heap() };
+		Block::Connection                  _session { Rump::env().env(), &_alloc };
 		Genode::size_t                     _blk_size; /* block size of the device   */
 		Block::sector_t                    _blk_cnt;  /* number of blocks of device */
 		Block::Session::Operations         _blk_ops;
-		Packet                             _p[COUNT];
-		Genode::Semaphore                  _alloc_sem;
-		Genode::Semaphore                  _packet_sem;
-		int                                _index_thread = 0;
-		int                                _index_client = 0;
-		Genode::Lock                       _alloc_lock;
-		bool                               _handle;
-		Genode::Signal_receiver            _receiver;
-		Genode::Signal_dispatcher<Backend> _disp_ack;
-		Genode::Signal_dispatcher<Backend> _disp_submit;
-
-
-		Genode::List<Packet> *_pending()
-		{
-			static Genode::List<Packet> _p;
-			return &_p;
-		}
-
-		bool _have_pending()
-		{
-			return !!_pending()->first();
-		}
-
-		Packet *_find(Block::Packet_descriptor &packet)
-		{
-			Packet *p = _pending()->first();
-			while (p) {
-				if (p->offset == packet.offset())
-					return p;
-
-				p = p->next();
-			}
-
-			Genode::error("pending packet not found");
-			return 0;
-		}
-		
-		Packet *_dequeue()
-		{
-			int idx;
-			for (int i = 0; i < COUNT; i++) {
-				idx = (_index_thread + i) % COUNT;
-				if (_p[idx].valid && !_p[idx].pending) {
-					_index_thread   = idx;
-					_p[idx].pending = true;
-					return &_p[idx];
-				}
-			}
-			Genode::warning("dequeue returned 0");
-			return 0;
-		}
-
-
-		void _free(Packet *p)
-		{
-			p->valid   = false;
-			p->pending = false;
-			_alloc_sem.up();
-		}
-
-		void _ready_to_submit(unsigned) { _handle = false; }
-
-		void _ack_avail(unsigned)
-		{
-			_handle = false;
-
-			while (_session.tx()->ack_avail()) {
-				Block::Packet_descriptor packet = _session.tx()->get_acked_packet();
-				Packet *p = _find(packet);
-
-				if (p->opcode == Block::Packet_descriptor::READ)
-					Genode::memcpy(p->data, _session.tx()->packet_content(packet),
-					               packet.block_count() * _blk_size);
-
-
-				/* sync session if requested  */
-				if (p->sync)
-					_session.sync();
-
-				int dummy;
-				if (verbose)
-					Genode::log("BIO done  p: ", p, " bio ", p->donearg);
-
-				rumpkern_sched(0, 0);
-				if (p->biodone)
-					p->biodone(p->donearg, p->cnt * _blk_size,
-					           packet.succeeded() ? 0 : EIO);
-				rumpkern_unsched(&dummy, 0);
-
-				_session.tx()->release_packet(packet);
-				_pending()->remove(p);
-				_free(p);
-			}
-		}
-
-		void _handle_signal()
-		{
-			_handle = true;
-
-			while (_handle) {
-				Genode::Signal s = _receiver.wait_for_signal();
-				static_cast<Genode::Signal_dispatcher_base *>
-					(s.context())->dispatch(s.num());
-			}
-		}
-
-	protected:
-
-		void entry()
-		{
-			_rump_upcalls.hyp_schedule();
-			_rump_upcalls.hyp_lwproc_newlwp(0);
-			_rump_upcalls.hyp_unschedule();
-
-			while (true) {
-
-				while (_packet_sem.cnt() <= 0 && _have_pending())
-					_handle_signal();
-
-				_packet_sem.down();
-
-				while (!_session.tx()->ready_to_submit())
-					_handle_signal();
-
-				Packet *p = _dequeue();
-
-				/* zero or sync request */
-				if (!p->cnt) {
-
-					if (p->sync)
-						_session.sync();
-
-					_free(p);
-					continue;
-				}
-
-				for (bool done = false; !done;)
-					try {
-						Block::Packet_descriptor packet(
-						_session.dma_alloc_packet(p->cnt * _blk_size),
-						                          p->opcode, p->blk, p->cnt);
-						/* got packet copy data */
-						if (p->opcode == Block::Packet_descriptor::WRITE)
-							Genode::memcpy(_session.tx()->packet_content(packet),
-							               p->data, p->cnt * _blk_size);
-						_session.tx()->submit_packet(packet);
-
-						/* mark as pending */
-						p->offset = packet.offset();
-						_pending()->insert(p);
-						done = true;
-					} catch(Block::Session::Tx::Source::Packet_alloc_failed) {
-					_handle_signal();
-				}
-			}
-		}
+		Genode::Lock                       _session_lock;
 
 	public:
 
 		Backend()
-		: Hard_context_thread("block_io", 0, 0, 0, false),
-		_alloc(Genode::env()->heap()),
-		_session(&_alloc),
-		_alloc_sem(COUNT),
-		_disp_ack(_receiver, *this, &Backend::_ack_avail),
-		_disp_submit(_receiver, *this, &Backend::_ready_to_submit)
 		{
-			_session.tx_channel()->sigh_ack_avail(_disp_ack);
-			_session.tx_channel()->sigh_ready_to_submit(_disp_submit);
 			_session.info(&_blk_cnt, &_blk_size, &_blk_ops);
-			Genode::log("Backend blk_size ", _blk_size);
-			Genode::memset(_p, 0, sizeof(_p));
-			start();
 		}
 
 		uint64_t block_count() const { return (uint64_t)_blk_cnt; }
@@ -235,44 +52,61 @@ class Backend : public Hard_context_thread
 			return _blk_ops.supported(Block::Packet_descriptor::WRITE);
 		}
 
-		Packet *alloc()
+		void sync()
 		{
-			int idx;
-			_alloc_sem.down();
-			Genode::Lock::Guard guard(_alloc_lock);
-			for (int i = 0; i < COUNT; i++) {
-				idx = (_index_client + i) % COUNT;
-				if (!_p[idx].valid) {
-					_p[idx].valid   = true;
-					_p[idx].pending = false;
-					_index_client = idx;
-					return &_p[idx];
-				}
-			}
-			Genode::warning("alloc returned 0");
-			return 0;
+			Genode::Lock::Guard guard(_session_lock);
+			_session.sync();
 		}
 
-		void submit() { _packet_sem.up(); }
+		bool submit(int op, int64_t offset, size_t length, void *data)
+		{
+			using namespace Block;
+
+			/* sync request */
+			if (op & RUMPUSER_BIO_SYNC) {
+				sync();
+				return true;
+			}
+
+			Genode::Lock::Guard guard(_session_lock);
+
+			Packet_descriptor::Opcode opcode;
+			opcode = op & RUMPUSER_BIO_WRITE ? Packet_descriptor::WRITE :
+			                                   Packet_descriptor::READ;
+			/* allocate packet */
+			try {
+				Packet_descriptor packet( _session.dma_alloc_packet(length),
+				                         opcode, offset / _blk_size,
+				                         length / _blk_size);
+
+				/* out packet -> copy data */
+				if (opcode == Packet_descriptor::WRITE)
+					Genode::memcpy(_session.tx()->packet_content(packet), data, length);
+
+				_session.tx()->submit_packet(packet);
+			} catch(Block::Session::Tx::Source::Packet_alloc_failed) {
+				Genode::error("I/O back end: Packet allocation failed!");
+				return false;
+			}
+
+			/* wait and process result */
+			Packet_descriptor packet = _session.tx()->get_acked_packet();
+
+			/* in packet */
+			if (opcode == Packet_descriptor::READ)
+				Genode::memcpy(data, _session.tx()->packet_content(packet), length);
+
+			bool succeeded = packet.succeeded();
+			_session.tx()->release_packet(packet);
+
+			return succeeded;
+		}
 };
 
 
-static Backend *backend()
+static Backend &backend()
 {
-	static Backend *_b = 0;
-
-	if (_b)
-		return _b;
-
-	int nlocks;
-	rumpkern_unsched(&nlocks, 0);
-	try {
-		_b = new(Genode::env()->heap())Backend();
-	} catch (Genode::Parent::Service_denied) {
-		Genode::error("opening block session denied!");
-	}
-	rumpkern_sched(nlocks, 0);
-
+	static Backend _b;
 	return _b;
 }
 
@@ -286,7 +120,7 @@ int rumpuser_getfileinfo(const char *name, uint64_t *size, int *type)
 		*type = RUMPUSER_FT_BLK;
 
 	if (size)
-		*size = backend()->block_count() * backend()->block_size();
+		*size = backend().block_count() * backend().block_size();
 
 	return 0;
 }
@@ -298,7 +132,7 @@ int rumpuser_open(const char *name, int mode, int *fdp)
 		return ENXIO;
 
 	/* check for writable */
-	if ((mode & RUMPUSER_OPEN_ACCMODE) && !backend()->writable())
+	if ((mode & RUMPUSER_OPEN_ACCMODE) && !backend().writable())
 		return EROFS;
 
 	*fdp = GENODE_FD;
@@ -310,40 +144,36 @@ void rumpuser_bio(int fd, int op, void *data, size_t dlen, int64_t off,
                   rump_biodone_fn biodone, void *donearg)
 {
 	int nlocks;
-
 	rumpkern_unsched(&nlocks, 0);
-	Packet *p = backend()->alloc();
 
+	/* data request */
 	if (verbose)
 		Genode::log("fd: ",   fd,   " "
 		            "op: ",   op,   " "
 		            "len: ",  dlen, " "
 		            "off: ",  Genode::Hex((unsigned long)off), " "
-		            "p: ",    p,       " "
 		            "bio ",   donearg, " "
 		            "sync: ", !!(op & RUMPUSER_BIO_SYNC));
 
-	p->opcode= op & RUMPUSER_BIO_WRITE ? Block::Packet_descriptor::WRITE :
-	                                     Block::Packet_descriptor::READ;
+	bool succeeded = backend().submit(op, off, dlen, data);
 
-	p->cnt     = dlen / backend()->block_size();
-	p->blk     = off  / backend()->block_size();
-	p->data    = data;
-	p->biodone = biodone;
-	p->donearg = donearg;
-	p->sync    = !!(op & RUMPUSER_BIO_SYNC);
-	backend()->submit();
 	rumpkern_sched(nlocks, 0);
+
+	if (biodone)
+		biodone(donearg, dlen, succeeded ? 0 : EIO);
 }
 
 
 void rump_io_backend_sync()
 {
-	/* send empty packet with sync request */
-	Packet *p = backend()->alloc();
-	p->cnt    = 0;
-	p->sync   = true;
-	backend()->submit();
+	backend().sync();
+}
+
+
+void rump_io_backend_init()
+{
+	/* create back end */
+	backend();
 }
 
 
diff --git a/repos/dde_rump/src/lib/rump/sync.cc b/repos/dde_rump/src/lib/rump/sync.cc
index 445c0554c6..65e741ad16 100644
--- a/repos/dde_rump/src/lib/rump/sync.cc
+++ b/repos/dde_rump/src/lib/rump/sync.cc
@@ -18,6 +18,8 @@ extern "C" {
 #include <base/lock.h>
 #include <util/fifo.h>
 #include <os/timed_semaphore.h>
+#include <rump/env.h>
+
 #include "sched.h"
 
 
@@ -106,7 +108,7 @@ struct rumpuser_mtx
 
 void rumpuser_mutex_init(struct rumpuser_mtx **mtxp, int flags)
 {
-	*mtxp = new(Genode::env()->heap()) rumpuser_mtx(flags);
+	*mtxp = new(Rump::env().heap()) rumpuser_mtx(flags);
 }
 
 
@@ -153,7 +155,7 @@ void rumpuser_mutex_exit(struct rumpuser_mtx *mtx)
 
 void rumpuser_mutex_destroy(struct rumpuser_mtx *mtx)
 {
-	destroy(Genode::env()->heap(), mtx);
+	destroy(Rump::env().heap(), mtx);
 }
 
 
@@ -274,13 +276,13 @@ struct rumpuser_cv {
 
 void rumpuser_cv_init(struct rumpuser_cv **cv)
 {
-	*cv = new(Genode::env()->heap())  rumpuser_cv();
+	*cv = new(Rump::env().heap())  rumpuser_cv();
 }
 
 
 void rumpuser_cv_destroy(struct rumpuser_cv *cv)
 {
-	destroy(Genode::env()->heap(), cv);
+	destroy(Rump::env().heap(), cv);
 }
 
 
@@ -464,7 +466,7 @@ struct rumpuser_rw
 
 void rumpuser_rw_init(struct rumpuser_rw **rw)
 {
-	*rw = new(Genode::env()->heap()) rumpuser_rw();
+	*rw = new(Rump::env().heap()) rumpuser_rw();
 }
 
 
@@ -531,6 +533,6 @@ void rumpuser_rw_held(int enum_rumprwlock, struct rumpuser_rw *rw, int *rv)
 
 void rumpuser_rw_destroy(struct rumpuser_rw *rw)
 {
-	destroy(Genode::env()->heap(), rw);
+	destroy(Rump::env().heap(), rw);
 }
 
diff --git a/repos/dde_rump/src/server/rump_fs/file_system.cc b/repos/dde_rump/src/server/rump_fs/file_system.cc
index 0dff819958..d89b125fb1 100644
--- a/repos/dde_rump/src/server/rump_fs/file_system.cc
+++ b/repos/dde_rump/src/server/rump_fs/file_system.cc
@@ -13,7 +13,7 @@
 
 #include "file_system.h"
 
-#include <rump/bootstrap.h>
+#include <rump/env.h>
 #include <rump_fs/fs.h>
 #include <util/string.h>
 #include <util/hard_context.h>
@@ -76,9 +76,9 @@ static bool check_read_only(Fs_type const &fs_type)
 }
 
 
-void File_system::init(Genode::Env &env, Genode::Allocator &alloc, Genode::Xml_node config)
+void File_system::init()
 {
-	Fs_type const fs_type = config.attribute_value("fs", Fs_type());
+	Fs_type const fs_type = Rump::env().config_rom().xml().attribute_value("fs", Fs_type());
 
 	if (!_check_type(fs_type)) {
 		Genode::error("Invalid or no file system given (use \'<config fs=\"<fs type>\"/>)");
@@ -87,12 +87,8 @@ void File_system::init(Genode::Env &env, Genode::Allocator &alloc, Genode::Xml_n
 	}
 	Genode::log("Using ", fs_type, " as file system");
 
-	/* make Genode env and heap known to the rump kernel */
-	rump_bootstrap_init(env, alloc);
-
 	/* start rump kernel */
 	rump_init();
-
 	/* register block device */ 
 	rump_pub_etfs_register(GENODE_DEVICE, GENODE_BLOCK_SESSION, RUMP_ETFS_BLK);
 
diff --git a/repos/dde_rump/src/server/rump_fs/file_system.h b/repos/dde_rump/src/server/rump_fs/file_system.h
index 645c75edcd..f8b7c3d7ae 100644
--- a/repos/dde_rump/src/server/rump_fs/file_system.h
+++ b/repos/dde_rump/src/server/rump_fs/file_system.h
@@ -31,7 +31,7 @@ extern "C" {
 }
 
 namespace File_system {
-	void init(Genode::Env &, Genode::Allocator &heap, Genode::Xml_node config);
+	void init();
 	bool supports_symlinks();
 }
 
diff --git a/repos/dde_rump/src/server/rump_fs/main.cc b/repos/dde_rump/src/server/rump_fs/main.cc
index 994cd8897b..39e5c48d25 100644
--- a/repos/dde_rump/src/server/rump_fs/main.cc
+++ b/repos/dde_rump/src/server/rump_fs/main.cc
@@ -24,6 +24,7 @@
 
 #include "undef.h"
 
+#include <rump/env.h>
 #include <rump_fs/fs.h>
 #include <sys/resource.h>
 #include "file_system.h"
@@ -173,7 +174,7 @@ class File_system::Session_component : public Session_rpc_object
 		~Session_component()
 		{
 			Dataspace_capability ds = tx_sink()->dataspace();
-			env()->ram_session()->free(static_cap_cast<Ram_dataspace>(ds));
+			Rump::env().env().ram().free(static_cap_cast<Ram_dataspace>(ds));
 			destroy(&_md_alloc, &_root);
 		}
 
@@ -491,11 +492,13 @@ struct File_system::Main
 
 	Root fs_root { env, sliced_heap };
 
-	Attached_rom_dataspace config { env, "config" };
-
 	Main(Genode::Env &env) : env(env)
 	{
-		File_system::init(env, heap, config.xml());
+		Rump::construct_env(env);
+
+		rump_io_backend_init();
+
+		File_system::init();
 
 			/* set all bits but the stickies */
 		rump_sys_umask(S_ISUID|S_ISGID|S_ISVTX);