README.compileopts revision 1.5 
1	$NetBSD: README.compileopts,v 1.5 2014/06/20 12:36:31 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================================================================================
81
82Per-component options:
83
84    RUMP_SYM_NORENAME
85
86values: regexp matching symbol names
87defval: <undefined>
88effect: Causes matching symbols from the component to not be renamed
89	into the rump kernel symbol namespace (rumpns_).  This option
90	can only be used in embedded environments where there is full
91	control over the platform's namespace.	Conversely, this option
92	cannot be used in kernel components which are not meant to be
93	tied to a specific platform.  Note: the value is processed by
94	make and must be appropriately escaped.  example:
95	RUMP_SYM_NORENAME=HYPERVISOR_|block$$
96	will not rename "^HYPERVISOR_" or "^block$"
97
98
99================================================================================
100
101
102The rest of the options described in this file are not intended to be
103set by users, but by the package building rump kernels.
104
105
106    RUMP_KERNEL_IS_LIBC
107
108values:	defined / not defined
109effect: Iff defined, export normal system call symbols from libc.
110	For example, without this option rump_sys_open() is exported.
111	With this option, both open() and rump_sys_open() are exported.
112	This option is meant for building systems where a rump kernel
113	is the only operating system like component.
114
115
116    RUMP_LDSCRIPT
117
118values: no/GNU/sun/ctor
119defval: GNU
120effect: Select the linker script to be used for linking rump kernel shared
121	library components.
122	no	- do not use a linker script
123	GNU	- use a linker script for GNU ld 2.18 and later
124	sun	- use a linker script for the Solaris linker
125	ctor	- do not use a linker script, make the code
126		  generate __attribute__((constructor))
127