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1 | About |
2 | ----- |
3 | |
4 | wARM is a combination of library and Linux kernel module for ARM processor |
5 | control. It was created because ARM processor allows to perform certain |
6 | operations in privileged modes only, and ARM Linux kernel is only providing |
7 | limited functionality through some private system calls. The code was |
8 | developed for GPH GP2X/Wiz consoles, but it should be possible to use it |
9 | on other ARM Linux systems (probably with modifications). |
10 | |
11 | Currently wARM provides various cache control operations and supports only |
12 | ARM9 family processors. |
13 | |
14 | |
15 | Usage |
16 | ----- |
17 | |
18 | The library consists of just 2 files: warm.c and warm.h, which should be |
19 | compiled into your program. The library performs module loading and |
20 | communication with it all by itself, you just need to call the right |
21 | functions. You will need to have a matching kernel module available for |
22 | kernel running on your device, several precompiled modules can be found |
23 | in bin/ directory: |
24 | |
25 | warm_2.4.25.o - for GP2X F100/F200 GPH firmwares |
26 | warm_2.4.26-open2x.o - for GP2X F100/F200 Open2x firmware |
27 | warm_2.6.24.ko - for Wiz GPH firmwares |
28 | |
29 | When the module is loaded into kernel, it creates /proc/warm file, which |
30 | can be read for some information about the CPU. |
31 | |
32 | |
33 | API |
34 | --- |
35 | |
36 | warm_init - must be called on startup. You must do it with current working |
37 | directory set to where kernel module can be found. |
38 | |
39 | warm_finish - should be called before exit to close internal files and unload |
40 | the module. |
41 | |
42 | warm_cache_op_range - |
43 | call to perform cache invalidation or clean operations (can |
44 | specify both with binary or - '|') for virtual address ranges. |
45 | In all cases write buffer is flushed (no operation can be |
46 | specified to just flush the write buffer). |
47 | |
48 | warm_cache_op_all - |
49 | same as above, only affects the whole cache. |
50 | |
51 | warm_change_cb_range - |
52 | set or clear C and/or B bits for memory region (if is_set is |
53 | nonzero, sets, else clears). The meaning of C and B bit |
54 | combinations is processor specific, for ARM9 C enables both |
55 | caching and buffering, B enables write buffer (when C is |
56 | cleared), or enables write-back caching (when C is set). |
57 | Note that in some cases the region needs to be accessed |
58 | before calling this function, so that kernel maps actual pages. |
59 | |
60 | warm_change_cb_upper - |
61 | same as above, only affects "upper" memory (RAM memory above |
62 | Linux accessible range, can be found in GP2X and Wiz). |
63 | |
64 | warm_virt2phys - |
65 | Converts virtual address to physical address. Note that the |
66 | returned address is only valid for one page where the address |
67 | points to (4KB in Linux). Next page will most likely point to |
68 | completely different physical memory location, instead of next |
69 | one. |
70 | |
71 | note: all operations except warm_cache_op_all() affect calling process only. |
72 | |
73 | |
74 | License |
75 | ------- |
76 | |
77 | * Copyright (c) GraÅžvydas "notaz" Ignotas, 2009 |
78 | * notasas a gmail d com |
79 | * |
80 | * Redistribution and use in source and binary forms, with or without |
81 | * modification, are permitted provided that the following conditions are met: |
82 | * * Redistributions of source code must retain the above copyright |
83 | * notice, this list of conditions and the following disclaimer. |
84 | * * Redistributions in binary form must reproduce the above copyright |
85 | * notice, this list of conditions and the following disclaimer in the |
86 | * documentation and/or other materials provided with the distribution. |
87 | * * Neither the name of the organization nor the |
88 | * names of its contributors may be used to endorse or promote products |
89 | * derived from this software without specific prior written permission. |
90 | * |
91 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
92 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
93 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
94 | * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
95 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
96 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
97 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
98 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
99 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
100 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
101 | |