doc/html/ref/hal-interfaces.html

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  84 NAME="HAL-INTERFACES">Chapter 9. HAL Interfaces</H1
  85 ><DIV
  86 CLASS="TOC"
  87 ><DL
  88 ><DT
  89 ><B
  90 >Table of Contents</B
  91 ></DT
  92 ><DT
  93 ><A
  94 HREF="hal-interfaces.html#HAL-BASE-DEFINITIONS"
  95 >Base Definitions</A
  96 ></DT
  97 ><DT
  98 ><A
  99 HREF="hal-architecture-characterization.html"
 100 >Architecture Characterization</A
 101 ></DT
 102 ><DT
 103 ><A
 104 HREF="hal-interrupt-handling.html"
 105 >Interrupt Handling</A
 106 ></DT
 107 ><DT
 108 ><A
 109 HREF="hal-input-and-output.html"
 110 >HAL I/O</A
 111 ></DT
 112 ><DT
 113 ><A
 114 HREF="hal-cache-control.html"
 115 >Cache Control</A
 116 ></DT
 117 ><DT
 118 ><A
 119 HREF="hal-linker-scripts.html"
 120 >Linker Scripts</A
 121 ></DT
 122 ><DT
 123 ><A
 124 HREF="hal-diagnostic-support.html"
 125 >Diagnostic Support</A
 126 ></DT
 127 ><DT
 128 ><A
 129 HREF="hal-smp-support.html"
 130 >SMP Support</A
 131 ></DT
 132 ></DL
 133 ></DIV
 134 ><P
 135 >This section describes the main HAL interfaces. </P
 136 ><DIV
 137 CLASS="SECTION"
 138 ><H1
 139 CLASS="SECTION"
 140 ><A
 141 NAME="HAL-BASE-DEFINITIONS">Base Definitions</H1
 142 ><P
 143 >These are definitions that characterize the properties of the base
 144 architecture that are used to compile the portable parts of the
 145 kernel. They are concerned with such things a portable type
 146 definitions, endianness, and labeling.</P
 147 ><P
 148 >These definitions are supplied by the
 149 <TT
 150 CLASS="FILENAME"
 151 >cyg/hal/basetype.h</TT
 152 > header file which is supplied
 153 by the architecture HAL. It is included automatically by
 154 <TT
 155 CLASS="FILENAME"
 156 >cyg/infra/cyg_type.h</TT
 157 >.</P
 158 ><DIV
 159 CLASS="SECTION"
 160 ><H2
 161 CLASS="SECTION"
 162 ><A
 163 NAME="AEN7743">Byte order</H2
 164 ><P
 165 ></P
 166 ><DIV
 167 CLASS="VARIABLELIST"
 168 ><DL
 169 ><DT
 170 ><TT
 171 CLASS="VARNAME"
 172 >CYG_BYTEORDER</TT
 173 ></DT
 174 ><DD
 175 ><P
 176 >      This defines the byte order of the target and must be set to either
 177       <TT
 178 CLASS="VARNAME"
 179 >CYG_LSBFIRST</TT
 180 > or <TT
 181 CLASS="VARNAME"
 182 >CYG_MSBFIRST</TT
 183 >.
 184       </P
 185 ></DD
 186 ></DL
 187 ></DIV
 188 ></DIV
 189 ><DIV
 190 CLASS="SECTION"
 191 ><H2
 192 CLASS="SECTION"
 193 ><A
 194 NAME="AEN7753">Label Translation</H2
 195 ><P
 196 ></P
 197 ><DIV
 198 CLASS="VARIABLELIST"
 199 ><DL
 200 ><DT
 201 ><TT
 202 CLASS="FUNCTION"
 203 >CYG_LABEL_NAME(name)</TT
 204 ></DT
 205 ><DD
 206 ><P
 207 >      This is a wrapper used in some C and C&#0043;&#0043; files which
 208       use labels defined in assembly code or the linker script.
 209       It need only be defined if the default implementation in
 210       <TT
 211 CLASS="FILENAME"
 212 >cyg/infra/cyg_type.h</TT
 213 >, which passes the name
 214       argument unaltered, is inadequate. It should be paired with
 215       <TT
 216 CLASS="FUNCTION"
 217 >CYG_LABEL_DEFN()</TT
 218 >.
 219       </P
 220 ></DD
 221 ><DT
 222 ><TT
 223 CLASS="FUNCTION"
 224 >CYG_LABEL_DEFN(name)</TT
 225 ></DT
 226 ><DD
 227 ><P
 228 >      This is a wrapper used in assembler sources and linker scripts
 229       which define labels.  It need only be defined if the default
 230       implementation in
 231       <TT
 232 CLASS="FILENAME"
 233 >cyg/infra/cyg_type.h</TT
 234 >, which passes the name
 235       argument unaltered, is inadequate. The most usual alternative
 236       definition of this macro prepends an underscore to the label
 237       name.
 238       </P
 239 ></DD
 240 ></DL
 241 ></DIV
 242 ></DIV
 243 ><DIV
 244 CLASS="SECTION"
 245 ><H2
 246 CLASS="SECTION"
 247 ><A
 248 NAME="AEN7769">Base types</H2
 249 ><TABLE
 250 BORDER="5"
 251 BGCOLOR="#E0E0F0"
 252 WIDTH="70%"
 253 ><TR
 254 ><TD
 255 ><PRE
 256 CLASS="PROGRAMLISTING"
 257 >       cyg_halint8
 258         cyg_halint16
 259         cyg_halint32
 260         cyg_halint64
 261         cyg_halcount8
 262         cyg_halcount16
 263         cyg_halcount32
 264         cyg_halcount64
 265         cyg_halbool</PRE
 266 ></TD
 267 ></TR
 268 ></TABLE
 269 ><P
 270 >These macros define the C base types that should be used to define
 271 variables of the given size. They only need to be defined if the
 272 default types specified in <TT
 273 CLASS="FILENAME"
 274 >cyg/infra/cyg_type.h</TT
 275 >
 276 cannot be used. Note that these are only the base types, they will be
 277 composed with <TT
 278 CLASS="LITERAL"
 279 >signed</TT
 280 > and
 281 <TT
 282 CLASS="LITERAL"
 283 >unsigned</TT
 284 > to form full type specifications.</P
 285 ></DIV
 286 ><DIV
 287 CLASS="SECTION"
 288 ><H2
 289 CLASS="SECTION"
 290 ><A
 291 NAME="AEN7776">Atomic types</H2
 292 ><TABLE
 293 BORDER="5"
 294 BGCOLOR="#E0E0F0"
 295 WIDTH="70%"
 296 ><TR
 297 ><TD
 298 ><PRE
 299 CLASS="PROGRAMLISTING"
 300 >       cyg_halatomic CYG_ATOMIC</PRE
 301 ></TD
 302 ></TR
 303 ></TABLE
 304 ><P
 305 >These types are guaranteed to be read or written in a single
 306 uninterruptible operation. It is architecture defined what size this
 307 type is, but it will be at least a byte.</P
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