hal.h

ecos为实时嵌入式操作系统

#ifndef CYGONCE_PKGCONF_HAL_H
#define CYGONCE_PKGCONF_HAL_H
// ====================================================================
//
//      pkgconf/hal.h
//
//      HAL configuration file
//
// ====================================================================
//####COPYRIGHTBEGIN####
//
// -------------------------------------------
// The contents of this file are subject to the Cygnus eCos Public License
// Version 1.0 (the "License"); you may not use this file except in
// compliance with the License.  You may obtain a copy of the License at
// http://sourceware.cygnus.com/ecos
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the
// License for the specific language governing rights and limitations under
// the License.
// 
// The Original Code is eCos - Embedded Cygnus Operating System, released
// September 30, 1998.
// 
// The Initial Developer of the Original Code is Cygnus.  Portions created
// by Cygnus are Copyright (C) 1998,1999 Cygnus Solutions.  All Rights Reserved.
// -------------------------------------------
//
//####COPYRIGHTEND####
// ====================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    nickg, jskov
// Contributors: nickg, jskov,
//               jlarmour
// Date:        1999-01-21
// Purpose:     To allow the user to edit HAL configuration options.
// Description:
//
//####DESCRIPTIONEND####
//
// ====================================================================

/* ---------------------------------------------------------------------
 * Some of the HAL configuration options depend on global options,
 * so it is necessary to include the global options first.
 */

#include <pkgconf/system.h>

/* ---------------------------------------------------------------------
   Define an overall package for the HAL. All other HAL packages
   live below this.

   {{CFG_DATA

   cdl_package CYGPKG_HAL {
       display "eCos HAL"
       type    dummy
       description "
           The eCos HAL package provide a porting layer for
           higher-level parts of the system such as the kernel and the
           C library. Each installation should have HAL packages for
           one or more architectures, and for each architecture there
           may be one or more supported platforms. It is necessary to
           select one target architecture and one platform for that
           architecture. There are also a number of configuration
           options that are common to all HAL packages."
           doc ref/ecos-ref/the-ecos-hardware-abstraction-layer-hal.html
   }

   }}CFG_DATA */

/* ---------------------------------------------------------------------
 * The platform-independent HAL configuration options go here,
 * inside a component CYGPKG_HAL_COMMON. In practice some of the
 * options are not completely platform-independent, but they are
 * likely to be available on the vast majority of platforms and
 * it is more convenient to provide them by default and let the
 * appropriate platforms disable them (probably via a suitable
 * interface).
 *
 * The common component is subdivided into components for
 * interrupt handling, thread context, and rom monitor/gdb support.

 {{CFG_DATA

 cdl_component CYGPKG_HAL_COMMON {
     display "Platform-independent HAL options"
     parent  CYGPKG_HAL
     type    dummy
     description "
         A number of configuration options are common to most or all
         HAL packages, for example options controlling how much state
         should be saved during a context switch. The implementations
         of these options will vary from architecture to architecture."
 }

 cdl_option CYGFUN_HAL_COMMON_KERNEL_SUPPORT {
     display  "Provide eCos kernel support"
     parent   CYGPKG_HAL_COMMON
     requires CYGPKG_KERNEL
     description "
         The HAL can be configured to either support the full eCos
         kernel, or to support only very simple applications which do
         not require a full kernel. If kernel support is not required
         then some of the startup, exception, and interrupt handling
         code can be eliminated."
 }

 }}CFG_DATA */
#define CYGFUN_HAL_COMMON_KERNEL_SUPPORT

/* {{CFG_DATA
   
 cdl_component CYGPKG_HAL_COMMON_INTERRUPTS {
     display "HAL interrupt handling"
     parent  CYGPKG_HAL_COMMON
     type    dummy
     description "
         A number of configuration options related to interrupt
         handling are common to most or all HAL packages, even though
         the implementations will vary from architecture to
         architecture."
 }

 cdl_option CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK {
     display      "Use separate stack for interrupts"
     parent       CYGPKG_HAL_COMMON_INTERRUPTS
     description  "
         When an interrupt occurs this interrupt can be handled either
         on the current stack or on a separate stack maintained by the
         HAL. Using a separate stack requires a small number of extra
         instructions in the interrupt handling code, but it has the
         advantage that it is no longer necessary to allow extra space
         in every thread stack for the interrupt handlers. The amount
         of extra space required depends on the interrupt handlers
         that are being used."
 }

 # NOTE: various parts of the system such as device drivers should
 # impose lower bounds on this. The actual lower bound depends on a
 # platform-specific value for startup overheads, and the minimum
 # sizes specified by the various device drivers. If interrupts are
 # not handled on a separate stack then only the startup overheads
 # are significant. If nested interrupts are disabled then the
 # lower bound is the maximum of the individual sizes, otherwise
 # it is the sum of these sizes. It is not currently possible to
 # express a relationship like this.
 cdl_option CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE {
     display        "Interrupt stack size"
     parent         CYGPKG_HAL_COMMON_INTERRUPTS
     type           count
     legal_values   1024 to 1048576
     description "
         This configuration option specifies the stack size in bytes
         for the interrupt stack. Typically this should be a multiple
         of 16, but the exact requirements will vary from architecture
         to architecture. The interrupt stack serves two separate
         purposes. It is used as the stack during system
         initialization. In addition, if the interrupt system is
         configured to use a separate stack then all interrupts will
         be processed on this stack. The exact memory requirements
         will vary from application to application, and will depend
         heavily on whether or not other interrupt-related options,
         for example nested interrupts, are enabled."
 }

 cdl_option CYGSEM_HAL_COMMON_INTERRUPTS_ALLOW_NESTING {
     display "Allow nested interrupts"
     parent  CYGPKG_HAL_COMMON_INTERRUPTS
     description "
         When an interrupt occurs the HAL interrupt handling code can
         either leave interrupts disabled for the duration of the
         interrupt handling code, or by doing some extra work it can
         reenable interrupts before invoking the interrupt handler and
         thus allow nested interrupts to happen. If all the interrupt
         handlers being used are small and do not involve any loops
         then it is usually better to disallow nested interrupts.
         However if any of the interrupt handlers are more complicated
         than nested interrupts will usually be required."
 }

 cdl_option CYGDBG_HAL_COMMON_INTERRUPTS_SAVE_MINIMUM_CONTEXT {
     display "Save minimum context on interrupt"
     parent  CYGPKG_HAL_COMMON_INTERRUPTS
     description "
         The HAL interrupt handling code can exploit the calling conventions
         defined for a given architecture to reduce the amount of state
         that has to be saved. Generally this improves performance and
         reduces code size. However it can make source-level debugging
         more difficult.
     "
 }
 
 cdl_option CYGIMP_HAL_COMMON_INTERRUPTS_CHAIN {
     display            "Chain all interrupts together"
     parent             CYGPKG_HAL_COMMON_INTERRUPTS
     description "
         Interrupts can be attached to vectors either singly, or be
         chained together. The latter is necessary if there is no way
         of discovering which device has interrupted without
         inspecting the device itself. It can also reduce the amount
         of RAM needed for interrupt decoding tables and code."
 }

 }}CFG_DATA

*/

#define CYGIMP_HAL_COMMON_INTERRUPTS_USE_INTERRUPT_STACK
#define CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE 4096
#undef  CYGSEM_HAL_COMMON_INTERRUPTS_ALLOW_NESTING
#define CYGDBG_HAL_COMMON_INTERRUPTS_SAVE_MINIMUM_CONTEXT
#undef  CYGIMP_HAL_COMMON_INTERRUPTS_CHAIN


/* {{CFG_DATA
   
 cdl_component CYGPKG_HAL_COMMON_CONTEXT {
     display "HAL context switch support"
     parent  CYGPKG_HAL_COMMON
     type    dummy
     description "
         A number of configuration options related to thread contexts
         are common to most or all HAL packages, even though the