1# 2# CDDL HEADER START 3# 4# The contents of this file are subject to the terms of the 5# Common Development and Distribution License (the "License"). 6# You may not use this file except in compliance with the License. 7# 8# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9# or http://www.opensolaris.org/os/licensing. 10# See the License for the specific language governing permissions 11# and limitations under the License. 12# 13# When distributing Covered Code, include this CDDL HEADER in each 14# file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15# If applicable, add the following below this CDDL HEADER, with the 16# fields enclosed by brackets "[]" replaced with your own identifying 17# information: Portions Copyright [yyyy] [name of copyright owner] 18# 19# CDDL HEADER END 20# 21 22# 23# Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24# Use is subject to license terms. 25# 26 27KERNEL MAKEFILE STRUCTURE 28------------------------- 29 30The advent of dynamic loading of kernel modules has obsoleted the 314.x kernel configuration scheme which was centered around a derived 32Makefile and a collection of derived header files generated by the 33config(8) program. This file describes the structure of the replacement 34"static" set of Makefiles. 35 36Some additional secondary goals were associated with the generation 37of these Makefiles. It should be noted that the ability to properly 38deal with derived Makefiles is an explicit non-goal of the ongoing 39NSE enhancements, so this project is a necessary consequence of that 40decision. 41 42All project goals are enumerated below: 43 441] To provide a set of static Makefiles to support kernel build 45 and installation. 46 472] To provide a set of static Makefiles which conform to the 48 "Makefiles Guidelines". (This document is currently available 49 on-line as "terminator:/usr/integration/doc/make.std") 50 513] To completely eliminate the config(8) program. 52 534] To provide a framework for linting the kernel (so that "lint free" 54 can be made an integration criterion, in addition to being general 55 good hygiene). 56 575] To eliminate the need for the small headers generated by config(8). 58 In the ddi/dki world this need is completely eliminated as drivers 59 will be expected to dynamically configure themselves. Interim support 60 for existing drivers will be provided. 61 626] To be able to "acquire" only the files needed to build a specific 63 module, if that is all that is needed. 64 657] To provide a framework suitable for the production of "implementation 66 architecture" independent modules. 67 688] To restructure the assembly language files to support the generation 69 of "lint-libraries" from them. 70 719] To provide support for the incidental Makefile targets many developers 72 are accustomed to (such as cscope and tags). These can be added to the 73 Makefiles asd required. (cscope is currently supported.) 74 75 76GENERAL STRUCTURE 77----------------- 78 79The source code layout is not generally effected by the Makefiles. However, 80the location of the generated files has changed dramatically. 81 82"Implementation architecture" independent modules are produced in 83individual directories (one per module) under the "instruction-set 84architecture" directory (i.e.: sparc). Similarly, "implementation 85architecture" dependent modules are produced in individual directories 86under the "implementation architecture" directory (i.e.: sun4, sun4c). 87It should be noted that currently (4/14/91) no implementation architecture 88modules exist. This situation is expected to change shortly. 89 90The driving Makefile for any module is located in the leaf directory 91where the module (and associated objects) are built. After a 'make 92clobber' operation, the Makefile is the only file remaining in that 93directory. Common definitions and rules are contained in suffixed 94Makefiles in non-leaf directories which are included in the leaf 95Makefiles. Non-suffixed Makefiles in non-leaf directories generally 96invoke lower level Makefiles to perform the actual tasks. 97 98uts/Makefile 99uts/sparc/Makefile 100uts/sun4c/Makefile 101uts/sun4c/svvs/Makefile 102 These Makefiles generally are cognizant of the components 103 made in subdirectories and invoke Makefiles in those sub- 104 directories to perform the actual build. Some targets (or 105 pseudo-targets) may be directly built at this level (such 106 as the cscope databases). 107 108uts/Makefile.uts 109 Contains common definitions for all possible architectures. 110 111uts/Makefile.targ 112 Contains common targets for all possible architectures. 113 114uts/common/Makefile.files 115uts/sun/Makefile.files 116uts/sparc/Makefile.files 117uts/sun4c/Makefile.files 118uts/sun4/Makefile.files 119 These Makefiles are divided into two sections. The first 120 section can be viewed as the equivalent of the "files" (sparc 121 and sun4c) and "files.cmn" (common and sun) files. These 122 define the object lists which define each module. The second 123 section defines the appropriate header search paths and other 124 machine specific global build parameters. 125 126uts/common/Makefile.rules 127uts/sun/Makefile.rules 128uts/sparc/Makefile.rules 129uts/sun4c/Makefile.rules 130uts/sun4/Makefile.rules 131 The files provide build rules (targets) which allow make to function 132 in a multiple directory environment. Each source tree below the 133 directory containing the Makefile has a build rule in the file. 134 135uts/sun4c/Makefile.sun4c 136uts/sun4/Makefile.sun4 137 These Makefile contains the definitions specific (defaults) to 138 the obvious "implementation architecture". These rules can be 139 overridden in specific leaf node Makefiles if necessary. 140 141uts/sun4c/unix/Makefile 142 Main driving Makefile for building /unix. 143 144uts/sun4c/MODULE/Makefile (for MODULE in arp, aoutexec, ...) 145 Main driving Makefile for building MODULE.kmod. 146 147uts/sun4c/unix.static/Makefile 148 Main driving Makefile for building a static unix (for development 149 work only). This Makefile is known to NSE, but its targets are 150 not. This makefile may be copied to additional parallel directories 151 to build multiple configurations. This configuration is roughly 152 equivalent to the GENERIC kernel of SunOS 4.x. 153 154The Makefiles are verbosely commented. It is desired that they should 155stay this way. 156 157 158USE 159--- 160 161Issuing the command 'make' in the uts directory will cause all supported, 162modularized kernels and modules to be built. 163 164Issuing the command 'make' in a uts/ARCHITECTURE directory (i.e.: uts/sparc) 165will cause all supported, "implementation architecture" independent modules 166for ARCHITECTURE to be built. 167 168Issuing the command 'make' in a uts/MACHINE directory (i.e.: uts/sun4c) 169will cause that kernel and all supported, "implementation architecture" 170dependent modules for MACHINE to be built. 171 172Issuing the command 'make' in the uts/MACHINE/unix directory will cause the 173kernel for MACHINE to be built (and unix.o). 174 175Issuing the command 'make' in a uts/MACHINE/MODULE or a uts/ARCHITECTURE/MODULE 176directory will cause MODULE.kmod to be built. 177 178 179LINT 180---- 181 182Linting is fairly similar to the builds, but it has an additional complication. 183In order to get meaningful output from lint pass2, all the modules must be 184linted together. This is accomplished by each module being responsible to 185produce its own pass1 output (file.ln, one per .c/.s file). It is also 186responsible for placing the a lint-library (llib-lMODULE) in the 187uts/MACHINE/lint-libs directory. The final full lint is accomplished by the 188Makefile in the uts/MACHINE directory by linting all the lint-libraries 189against each other. 190 191Note that there is no equivalent to Locore.c in the current source base. 192The C prototypes are in the .s files. As example: 193 194 #if defined(lint) 195 int 196 blort(int, int) 197 { return 0 } 198 #else /* lint */ 199 200 ENTRY(blort) 201 ld [%i0],.... 202 .... 203 SET_SIZE(blort) 204 205 #endif /* lint */ 206 207 208COMPONENT HIERARCHY 209------------------ 210 211The component hierarchy has been restructured to allow the acquisition of 212more finely grained objects; specificly a kernel module. The basic component 213structure is: 214 215 :src:uts.all --+--> :sparc --+--> :MODULES... (none currently) 216 | 217 +--> :sun4c --+--> :unix 218 | | 219 | +--> :MODULES... 220 | | 221 | +--> :unix.static 222 | 223 +--> :sun4 ---+--> :unix 224 | | 225 | +--> :MODULES... 226 | | 227 | +--> :unix.static 228 ... 229 230The above diagram does not reflect the full component tree. The full component 231tree may be displayed with the "nsecomp list -r :src:uts.all" command. 232 233 234COMMON OPERATIONS 235----------------- 236 237Adding a New Kernel Module 238-------------------------- 239 240 0] Create the source files (and directories) as usual. 241 242 1] Edit uts/*/Makefile.files to define the set of objects. By convention 243 the symbolic name of this set is of the form MODULE_OBJS, where 244 MODULE is the module name (i.e.: namefs). The files in each subtree 245 should be defined in the Makefile.files in the root directory of that 246 subtree. Note that they are defined using the += operator, so that 247 the set can be built across multiple files. As example: 248 249 NAMEFS_OBJS += namevfs.o namevno.o 250 251 Each source file needs a build rule in the corresponding Makefile.rules 252 file (compilation and lint). A typical pair of entries would be: 253 254 $(OBJS_DIR)/mem.o: $(UTSBASE)/sun4c/io/mem.c 255 $(COMPILE.c) -o $@ $(UTSBASE)/sun4c/io/mem.c 256 257 $(LINTS_DIR)/mem.ln: $(UTSBASE)/sun4c/io/mem.c 258 @($(LHEAD) $(LINT.c) $(UTSBASE)/sun4c/io/mem.c $(LTAIL)) 259 260 2] Create build directories in the appropriate places. If the module 261 can be built in a machine independent way, this would be in the 262 "instruction set architecture" directory (i.e.: sparc). If not, these 263 directories would be created for all appropriate "implementation 264 architecture" dependent directories (i.e.: sun4, sun4c). 265 266 3] In each build directory, create a Makefile. This can usually be 267 accomplished by copying a Makefile from a parallel directory and 268 editing the following lines (in addition to comments). 269 270 MODULE = namefs 271 - replace with module name 272 OBJECTS = $(NAMEFS_OBJS:%=$(OBJS_DIR)/%) 273 LINTS = $(NAMEFS_OBJS:%.o=$(LINTS_DIR)/%.ln) 274 - replace with MODULE_OBJS 275 ROOTMODULE = $(ROOT_FS_DIR)/$(MODULE).kmod 276 - replace directory part with the appropriate 277 installation directory name (see Makefile.uts) 278 279 If a custom version of modstubs.o is needed to check the undefines 280 for this routine, the following lines need to appear in the 281 Makefile (after the inclusion of Makefile.mach (i.e.: Makefile.sun4c)). 282 283 MODSTUBS_DIR = $(OBJS_DIR) 284 $(MODSTUBS_O) := AS_CPPFLAGS += -DNAMEFS_MODULE 285 - replace "-DNAMEFS_MODULE" with the appropriate flag 286 for the modstubs.o assembly. 287 CLEANFILES += $(MODSTUBS_O) 288 289 4] Edit the parent Makefile.mach (i.e.: Makefile.sun4c) to know about 290 the new module: 291 292 FS_KMODS += fd fifo namefs nfs proc spec ufs 293 ------ 294Any additional questions can be easily answered by looking at the many 295existing examples. 296 297 298Moving a Module to the "Implementation Architecture" Independent Build 299---------------------------------------------------------------------- 300 301 1] Create the build directory under the appropriate "instruction 302 set architecture" build directory (i.e.: sparc/MODULE). 303 304 2] Move the Makefile from the "implementation architecture" build 305 directory (i.e.: sun4c/MODULE) to the directory created above. 306 Edit this Makefile to reflect the change of parent (trivial: 307 comments, paths and includes). 308 309 3] Edit the "implementation architecture" directory Makefile (i.e.: 310 Makefile.sun4c) to *not* know about this module and edit the 311 "instruction set architecture" directory Makefile (i.e.: 312 Makefile.sparc) to know about it. 313 314