README.compileopts revision 1.6 
1	$NetBSD: README.compileopts,v 1.6 2014/07/11 20:26:31 justin 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
82Rumpuser options:
83
84    RUMPUSER_THREADS
85
86values: pthread/none/fiber or <undefined>
87defval: <undefined>
88effect: Define the way threading is implemented in the rumpuser hypercall
89	implmentation.
90	<undefined> - use default implementation (currently "pthread")
91	pthread     - use pthreads to implement threading
92	none        - do not support kernel threads at all
93	fiber       - user a fiber interface, cooperatively scheduled contexts
94
95
96================================================================================
97
98Per-component options:
99
100    RUMP_SYM_NORENAME
101
102values: regexp matching symbol names
103defval: <undefined>
104effect: Causes matching symbols from the component to not be renamed
105	into the rump kernel symbol namespace (rumpns_).  This option
106	can only be used in embedded environments where there is full
107	control over the platform's namespace.	Conversely, this option
108	cannot be used in kernel components which are not meant to be
109	tied to a specific platform.  Note: the value is processed by
110	make and must be appropriately escaped.  example:
111	RUMP_SYM_NORENAME=HYPERVISOR_|block$$
112	will not rename "^HYPERVISOR_" or "^block$"
113
114
115================================================================================
116
117
118The rest of the options described in this file are not intended to be
119set by users, but by the package building rump kernels.
120
121
122    RUMP_KERNEL_IS_LIBC
123
124values:	defined / not defined
125effect: Iff defined, export normal system call symbols from libc.
126	For example, without this option rump_sys_open() is exported.
127	With this option, both open() and rump_sys_open() are exported.
128	This option is meant for building systems where a rump kernel
129	is the only operating system like component.
130
131
132    RUMP_LDSCRIPT
133
134values: no/GNU/sun/ctor
135defval: GNU
136effect: Select the linker script to be used for linking rump kernel shared
137	library components.
138	no	- do not use a linker script
139	GNU	- use a linker script for GNU ld 2.18 and later
140	sun	- use a linker script for the Solaris linker
141	ctor	- do not use a linker script, make the code
142		  generate __attribute__((constructor))
143