|
[ source navigation ] [ diff markup ] [ identifier search ] [ general search ] |
|||
|
001 /* Copyright (C) 2005 David Decotigny 002 003 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any later version. 007 008 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details. 012 013 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 017 */ 018 019 #include <crt.h> 020 #include <libc.h> 021 #include <string.h> 022 #include <stdarg.h> 023 #include <debug.h> 024 025 026 /** 027 * @file myprog12.c 028 * 029 * /dev/mem & /dev/kmem tests 030 */ 031 032 033 int main(void) 034 { 035 char *zoup; 036 037 /* Test /dev/mem */ 038 039 /* Map the x86 text framebuffer into this process address space in 040 shared mode */ 041 int fd; 042 043 fd = open("/dev/mem", O_RDWR); 044 zoup = mmap(0, 4096, PROT_READ | PROT_WRITE, 045 MAP_SHARED, 046 fd, 0xb8000); 047 close(fd); 048 049 bochs_printf("mapped mem @%x\n", (unsigned)zoup); 050 _sos_syscall1(4004, (unsigned)"Apres mmap video"); 051 052 /* Do some forks to complicate things */ 053 fork(); 054 fork(); 055 056 /* Write a string into it: it should be printed on screen */ 057 strzcpy(zoup + 80*5*2 + 10*2, 058 "H e l l o W o r l d f r o m S O S i n U s e r M o d e ", 059 250); 060 061 /* Map the x86 text framebuffer into this process address space in 062 PRIVATE mode */ 063 fd = open("/dev/mem", O_RDWR); 064 zoup = mmap(0, 4096, PROT_READ | PROT_WRITE, 065 0 /* Private */, 066 fd, 0xb8000); 067 close(fd); 068 bochs_printf("mapped mem @%x\n", (unsigned)zoup); 069 _sos_syscall1(4004, (unsigned)"Apres mmap video"); 070 071 /* Do some forks to complicate things */ 072 fork(); 073 fork(); 074 075 /* Write a string into it: it should NOT be printed on screen since 076 the mapping is private */ 077 strzcpy(zoup + 80*5*2 + 10*2, 078 "Y o u c a n n o t S e e T h i s ! ", 079 250); 080 081 /* Test /dev/kmem */ 082 083 /* remap some kernel pages in user space. We'd better map this in 084 "private" mode here, this way we can do whatever we like in this 085 area. If we'd mapped it read/write, this would overwrite kernel 086 data/code, causing a crash sooner or later. */ 087 fd = open("/dev/kmem", O_RDWR); 088 zoup = mmap(0, 100*4096, PROT_READ | PROT_WRITE, 089 0 /* private */, 090 fd, 0x00201000); 091 close(fd); 092 bochs_printf("mapped kmem @%x\n", (unsigned)zoup); 093 _sos_syscall1(4004, (unsigned)"Apres mmap kernel"); 094 095 /* Do some forks to complicate things */ 096 fork(); 097 fork(); 098 099 /* Overwriting our private "copy" of kernel */ 100 memset(zoup, 0x0, 10*4096); 101 _sos_syscall1(4004, (unsigned)"Apres memset kernel"); 102 103 return 0; 104 }
[ source navigation ] | [ diff markup ] | [ identifier search ] | [ general search ] |