| | 1 | /* tables.h |
| | 2 | * Linker table helper macros. |
| | 3 | * NetWatch system management mode administration console |
| | 4 | * |
| | 5 | * Copyright 2009, Google Inc. |
| | 6 | * All rights reserved. |
| | 7 | * |
| | 8 | * Redistribution and use in source and binary forms, with or without |
| | 9 | * modification, are permitted provided that the following conditions are |
| | 10 | * met: |
| | 11 | * |
| | 12 | * * Redistributions of source code must retain the above copyright |
| | 13 | * notice, this list of conditions and the following disclaimer. |
| | 14 | * * Redistributions in binary form must reproduce the above |
| | 15 | * copyright notice, this list of conditions and the following disclaimer |
| | 16 | * in the documentation and/or other materials provided with the |
| | 17 | * distribution. |
| | 18 | * * Neither the name of Google Inc. nor the names of its |
| | 19 | * contributors may be used to endorse or promote products derived from |
| | 20 | * this software without specific prior written permission. |
| | 21 | * |
| | 22 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| | 23 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| | 24 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| | 25 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| | 26 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| | 27 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| | 28 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| | 29 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| | 30 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| | 31 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| | 32 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| | 33 | */ |
| | 34 | |
| | 35 | #ifndef __TABLES_H |
| | 36 | #define __TABLES_H |
| | 37 | |
| | 38 | /* Linker tables are a beautiful, evil piece of magic. |
| | 39 | * |
| | 40 | * The idea is this; |
| | 41 | * - For each table, define start and end pointers as zero-length arrays. |
| | 42 | * - Define however many data values as constants of the appropriate type |
| | 43 | * - Put each in its own section. For example, 'start' is in section |
| | 44 | * .table.foo; the data elemnts are in section .table.foo.1 (or other values |
| | 45 | * for explicit ordering); and 'end' is in .table.foo.END. |
| | 46 | * - Merge the sections together with the following linker script entry: |
| | 47 | * *(SORT(.table.*)) |
| | 48 | * |
| | 49 | * This has the effect that the start symbol points to the first value in the |
| | 50 | * table, and the end symbol points to the last. The number of values is |
| | 51 | * simply (table_foo_end - table_foo_start). |
| | 52 | * |
| | 53 | * And everything Just Works. Etherboot and the Linux kernel both use this |
| | 54 | * for identifying linked-in modules; they have a somewhat more elaborate |
| | 55 | * macro infastructure, but at the moment there are only two tables in |
| | 56 | * NetWatch (network protocols and built-in drivers), so less is needed. |
| | 57 | */ |
| | 58 | |
| | 59 | #define PROTOCOL(x) void (* const x##_ptr)(void) \ |
| | 60 | __attribute__((section(".table.protocols.1"))) = x |
| | 61 | |
| | 62 | |
| | 63 | |
| | 64 | #define TABLE(typ, name) \ |
| | 65 | typ name##_table[0] __attribute__((section(".table." #name ))); \ |
| | 66 | typ name##_table_end[0] __attribute__((section(".table." #name ".END"))); |
| | 67 | |
| | 68 | #define TABLE_LENGTH(name) (name##_table_end - name##_table) |
| | 69 | |
| | 70 | #endif /* __TABLES_H */ |
| | 71 | |
git.joshuawise.com / netwatch.git / blame_incremental