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comparison packages/kernel/current/cdl/interrupts.cdl @ 76:435cced73e2f ecos-v1_3_1-release

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eCos v1.3.1 merged from eCos master repository on 2000-03-27-23:22:51-BST
author jlarmour
date Tue, 28 Mar 2000 14:10:45 +0000
parents
children 6736c52df507
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75:41bf073c0c32 76:435cced73e2f
1 # ====================================================================
2 #
3 # interrupts.cdl
4 #
5 # configuration data related to kernel interrupt handling
6 #
7 # ====================================================================
8 #####COPYRIGHTBEGIN####
9 #
10 # -------------------------------------------
11 # The contents of this file are subject to the Red Hat eCos Public License
12 # Version 1.1 (the "License"); you may not use this file except in
13 # compliance with the License. You may obtain a copy of the License at
14 # http://www.redhat.com/
15 #
16 # Software distributed under the License is distributed on an "AS IS"
17 # basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
18 # License for the specific language governing rights and limitations under
19 # the License.
20 #
21 # The Original Code is eCos - Embedded Configurable Operating System,
22 # released September 30, 1998.
23 #
24 # The Initial Developer of the Original Code is Red Hat.
25 # Portions created by Red Hat are
26 # Copyright (C) 1998, 1999, 2000 Red Hat, Inc.
27 # All Rights Reserved.
28 # -------------------------------------------
29 #
30 #####COPYRIGHTEND####
31 # ====================================================================
32 ######DESCRIPTIONBEGIN####
33 #
34 # Author(s): bartv
35 # Original data: nickg
36 # Contributors:
37 # Date: 1999-06-13
38 #
39 #####DESCRIPTIONEND####
40 #
41 # ====================================================================
42
43 # NOTE: the choice of list vs table should not be two separate
44 # options. There is a single option which must have one of
45 # two legal values.
46 cdl_component CYGIMP_KERNEL_INTERRUPTS_DSRS {
47 display "Use delayed service routines (DSRs)"
48 default_value 1
49 description "
50 In eCos the recommended way to handle device interrupts is to
51 do a minimum amount of work inside the low level interrupt
52 handler itself, and instead do as much as possible in a
53 Delayed Service Routine or DSR. If an application does not
54 make use of DSRs directly or indirectly then it is possible
55 to disable the DSR support completely, which reduces the
56 overheads of context switches and interrupt handling. Note
57 that the kernel real-time clock makes use of DSRs, as do many
58 of the device drivers. "
59
60 cdl_interface CYGINT_KERNEL_INTERRUPTS_DSRS {
61 requires 1 == CYGINT_KERNEL_INTERRUPTS_DSRS
62 }
63
64 # NOTE: the choice of list vs table should not be two separate
65 # options. There is a single option which must have one of
66 # two legal values.
67 cdl_option CYGIMP_KERNEL_INTERRUPTS_DSRS_LIST {
68 display "Use linked lists for DSRs"
69 default_value 1
70 implements CYGINT_KERNEL_INTERRUPTS_DSRS
71 description "
72 When DSR support is enabled the kernel must keep track of all
73 the DSRs that are pending. This information can be kept in a
74 fixed-size table or in a linked list. The list implementation
75 requires that the kernel disable interrupts for a very short
76 period of time outside interrupt handlers, but there is no
77 possibility of a table overflow occurring."
78 }
79
80 cdl_component CYGIMP_KERNEL_INTERRUPTS_DSRS_TABLE {
81 display "Use fixed-size table for DSRs"
82 default_value 0
83 implements CYGINT_KERNEL_INTERRUPTS_DSRS
84 description "
85 When DSR support is enabled the kernel must keep track of all
86 the DSRs that are pending. This information can be kept in a
87 fixed-size table or in a linked list. The table
88 implementation involves a very small risk of overflow at
89 run-time if a given interrupt source is able to have more
90 than one pending DSR. However it has the advantage that
91 the kernel does not need to disable interrupts outside
92 interrupt handlers."
93
94 cdl_option CYGNUM_KERNEL_INTERRUPTS_DSRS_TABLE_SIZE {
95 display "Number of entries in fixed-size DSR table"
96 flavor data
97 legal_values 2 to 1024
98 default_value 32
99 description "
100 When DSR support is enabled the kernel must keep track of all
101 the DSRs that are pending. One approach involves a fixed-size
102 table, which involves a very small risk of overflow at
103 run-time. By increasing the table size it is possible to reduce
104 this risk."
105 }
106 }
107
108 cdl_option CYGIMP_KERNEL_INTERRUPTS_CHAIN {
109 display "Chain all interrupts together"
110 requires CYGIMP_HAL_COMMON_INTERRUPTS_CHAIN
111 default_value 0
112 description "
113 Interrupts can be attached to vectors either singly, or be
114 chained together. The latter is necessary if there is no way
115 of discovering which device has interrupted without
116 inspecting the device itself. It can also reduce the amount
117 of RAM needed for interrupt decoding tables and code."
118 }
119 }