README.compileopts revision 1.11 
1	$NetBSD: README.compileopts,v 1.11 2015/06/03 14:40:11 pooka Exp $
2
3This file describes compile-time options for rump kernels.  Additionally,
4NetBSD build options will have an effect.  See src/share/mk/bsd.README
5for a desciption of NetBSD build options.
6
7Note: after changing an option, do a clean build.
8
9Global options:
10
11
12    RUMP_DIAGNOSTIC
13
14values:	yes|no
15defval:	yes
16effect:	Iff "yes", build with -DDIAGNOSTIC.
17
18
19    RUMP_DEBUG
20
21values:	defined / not defined
22effect:	Iff defined, build with -DDEBUG.
23
24
25    RUMP_LOCKDEBUG
26
27values:	defined / not defined
28effect:	Iff defined, build with -DLOCKDEBUG.
29
30
31    RUMP_KTRACE
32
33values:	yes|no
34defval:	yes
35effect:	Iff "yes", build with -DKTRACE.
36
37
38    RUMP_LOCKS_UP
39
40values: yes|no
41defval:	no
42effect: If "yes", build rump kernel with uniprocess-optimized locking.
43	An implication of this is that RUMP_NCPU==1 is required at
44	runtime.  If "no", build with multiprocessor-capable locking.
45
46
47    RUMP_UNREAL_ALLOCATORS
48
49values: yes|no
50defval:	no
51effect: If "yes", build version of kmem_alloc, pool and pool_cache
52	that directly relegate allocation to a hypercall.  If "no",
53	build the regular NetBSD memory allocators which use
54	page-sized memory allocation hypercalls.
55
56
57    RUMP_VIRTIF
58
59values:	yes|no
60defval:	yes
61effect:	Iff "yes", build the virt(4) network interface.  Turning this
62	off may be necessary on systems that lack the necessary headers,
63	e.g. musl libc based Linux.
64
65
66    RUMP_CURLWP
67
68values: hypercall/__thread/register or <undefined>
69defval: <undefined>
70effect: Control how curlwp is obtained in a rump kernel.  This is
71	a very frequently accessed thread-local variable, and optimizing
72	access has a significant performance impact.  Note that all
73	options are not available on hosts/machine architectures.
74	<undefined> - use default implementation (currently "hypercall")
75	hypercall   - use a hypercall to fetch the value
76	__thread    - use the __thread feature to fetch value via TLS
77	register    - use a dedicated register (implies -ffixed)
78
79
80    RUMP_NBCOMPAT
81
82values: comma-separated list of releases; e.g. "60,70";
83	or "all" or "default" or "none".  Currently default == all (but
84	might not be so in the future)
85defval:	all
86effect:	Builds NetBSD COMPAT_nn code for each of the elements in the list.
87	This option is useful only when building rump kernels for
88	NetBSD userspace, and an empty value may be supplied elsewhere.
89
90
91================================================================================
92
93Rumpuser options:
94
95    RUMPUSER_THREADS
96
97values: pthread/none/fiber or <undefined>
98defval: <undefined>
99effect: Define the way threading is implemented in the rumpuser hypercall
100	implmentation.
101	<undefined> - use default implementation (currently "pthread")
102	pthread     - use pthreads to implement threading
103	none        - do not support kernel threads at all
104	fiber       - user a fiber interface, cooperatively scheduled contexts
105
106
107================================================================================
108
109Per-component options:
110
111    RUMP_SYM_NORENAME
112
113values: regexp matching symbol names
114defval: <undefined>
115effect: Causes matching symbols from the component to not be renamed
116	into the rump kernel symbol namespace (rumpns_).  This option
117	can only be used in embedded environments where there is full
118	control over the platform's namespace.	Conversely, this option
119	cannot be used in kernel components which are not meant to be
120	tied to a specific platform.  Note: the value is processed by
121	make and must be appropriately escaped.  example:
122	RUMP_SYM_NORENAME=HYPERVISOR_|block$$
123	will not rename "^HYPERVISOR_" or "^block$"
124
125
126================================================================================
127
128
129The rest of the options described in this file are not intended to be
130set by users, but by the package building rump kernels.
131
132
133    RUMP_KERNEL_IS_LIBC
134
135values:	defined / not defined
136effect: Iff defined, export normal system call symbols from libc.
137	For example, without this option rump_sys_open() is exported.
138	With this option, both open() and rump_sys_open() are exported.
139	This option is meant for building systems where a rump kernel
140	is the only operating system like component.
141
142
143    RUMP_LDSCRIPT
144
145values: no/GNU/sun/ctor
146defval: GNU
147effect: Select the linker script to be used for linking rump kernel shared
148	library components.
149	no	- do not use a linker script
150	GNU	- use a linker script for GNU ld 2.18 and later
151	sun	- use a linker script for the Solaris linker
152	ctor	- do not use a linker script, make the code
153		  generate __attribute__((constructor))
154