Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * misc.c
  3  * 
  4  * This is a collection of several routines from gzip-1.0.3 
  5  * adapted for Linux.
  6  *
  7  * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
  8  *
  9  * Modified for ARM Linux by Russell King
 10  *
 11  * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
 12  *  For this code to run directly from Flash, all constant variables must
 13  *  be marked with 'const' and all other variables initialized at run-time 
 14  *  only.  This way all non constant variables will end up in the bss segment,
 15  *  which should point to addresses in RAM and cleared to 0 on start.
 16  *  This allows for a much quicker boot time.
 17  */
 18 
 19 unsigned int __machine_arch_type;
 20 
 21 #include <linux/compiler.h>     /* for inline */
 22 #include <linux/types.h>        /* for size_t */
 23 #include <linux/stddef.h>       /* for NULL */
 24 #include <asm/string.h>
 25 
 26 #ifdef STANDALONE_DEBUG
 27 #define putstr printf
 28 #else
 29 
 30 static void putstr(const char *ptr);
 31 
 32 #include <mach/uncompress.h>
 33 
 34 #ifdef CONFIG_DEBUG_ICEDCC
 35 
 36 #ifdef CONFIG_CPU_V6
 37 
 38 static void icedcc_putc(int ch)
 39 {
 40         int status, i = 0x4000000;
 41 
 42         do {
 43                 if (--i < 0)
 44                         return;
 45 
 46                 asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
 47         } while (status & (1 << 29));
 48 
 49         asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
 50 }
 51 #elif defined(CONFIG_CPU_XSCALE)
 52 
 53 static void icedcc_putc(int ch)
 54 {
 55         int status, i = 0x4000000;
 56 
 57         do {
 58                 if (--i < 0)
 59                         return;
 60 
 61                 asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
 62         } while (status & (1 << 28));
 63 
 64         asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
 65 }
 66 
 67 #else
 68 
 69 static void icedcc_putc(int ch)
 70 {
 71         int status, i = 0x4000000;
 72 
 73         do {
 74                 if (--i < 0)
 75                         return;
 76 
 77                 asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
 78         } while (status & 2);
 79 
 80         asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
 81 }
 82 
 83 #endif
 84 
 85 #define putc(ch)        icedcc_putc(ch)
 86 #define flush() do { } while (0)
 87 #endif
 88 
 89 static void putstr(const char *ptr)
 90 {
 91         char c;
 92 
 93         while ((c = *ptr++) != '\0') {
 94                 if (c == '\n')
 95                         putc('\r');
 96                 putc(c);
 97         }
 98 
 99         flush();
100 }
101 
102 #endif
103 
104 #define __ptr_t void *
105 
106 #define memzero(s,n) __memzero(s,n)
107 
108 /*
109  * Optimised C version of memzero for the ARM.
110  */
111 void __memzero (__ptr_t s, size_t n)
112 {
113         union { void *vp; unsigned long *ulp; unsigned char *ucp; } u;
114         int i;
115 
116         u.vp = s;
117 
118         for (i = n >> 5; i > 0; i--) {
119                 *u.ulp++ = 0;
120                 *u.ulp++ = 0;
121                 *u.ulp++ = 0;
122                 *u.ulp++ = 0;
123                 *u.ulp++ = 0;
124                 *u.ulp++ = 0;
125                 *u.ulp++ = 0;
126                 *u.ulp++ = 0;
127         }
128 
129         if (n & 1 << 4) {
130                 *u.ulp++ = 0;
131                 *u.ulp++ = 0;
132                 *u.ulp++ = 0;
133                 *u.ulp++ = 0;
134         }
135 
136         if (n & 1 << 3) {
137                 *u.ulp++ = 0;
138                 *u.ulp++ = 0;
139         }
140 
141         if (n & 1 << 2)
142                 *u.ulp++ = 0;
143 
144         if (n & 1 << 1) {
145                 *u.ucp++ = 0;
146                 *u.ucp++ = 0;
147         }
148 
149         if (n & 1)
150                 *u.ucp++ = 0;
151 }
152 
153 static inline __ptr_t memcpy(__ptr_t __dest, __const __ptr_t __src,
154                             size_t __n)
155 {
156         int i = 0;
157         unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
158 
159         for (i = __n >> 3; i > 0; i--) {
160                 *d++ = *s++;
161                 *d++ = *s++;
162                 *d++ = *s++;
163                 *d++ = *s++;
164                 *d++ = *s++;
165                 *d++ = *s++;
166                 *d++ = *s++;
167                 *d++ = *s++;
168         }
169 
170         if (__n & 1 << 2) {
171                 *d++ = *s++;
172                 *d++ = *s++;
173                 *d++ = *s++;
174                 *d++ = *s++;
175         }
176 
177         if (__n & 1 << 1) {
178                 *d++ = *s++;
179                 *d++ = *s++;
180         }
181 
182         if (__n & 1)
183                 *d++ = *s++;
184 
185         return __dest;
186 }
187 
188 /*
189  * gzip delarations
190  */
191 #define OF(args)  args
192 #define STATIC static
193 
194 typedef unsigned char  uch;
195 typedef unsigned short ush;
196 typedef unsigned long  ulg;
197 
198 #define WSIZE 0x8000            /* Window size must be at least 32k, */
199                                 /* and a power of two */
200 
201 static uch *inbuf;              /* input buffer */
202 static uch window[WSIZE];       /* Sliding window buffer */
203 
204 static unsigned insize;         /* valid bytes in inbuf */
205 static unsigned inptr;          /* index of next byte to be processed in inbuf */
206 static unsigned outcnt;         /* bytes in output buffer */
207 
208 /* gzip flag byte */
209 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
210 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
211 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
212 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
213 #define COMMENT      0x10 /* bit 4 set: file comment present */
214 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
215 #define RESERVED     0xC0 /* bit 6,7:   reserved */
216 
217 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
218 
219 /* Diagnostic functions */
220 #ifdef DEBUG
221 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
222 #  define Trace(x) fprintf x
223 #  define Tracev(x) {if (verbose) fprintf x ;}
224 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
225 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
226 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
227 #else
228 #  define Assert(cond,msg)
229 #  define Trace(x)
230 #  define Tracev(x)
231 #  define Tracevv(x)
232 #  define Tracec(c,x)
233 #  define Tracecv(c,x)
234 #endif
235 
236 static int  fill_inbuf(void);
237 static void flush_window(void);
238 static void error(char *m);
239 
240 extern char input_data[];
241 extern char input_data_end[];
242 
243 static uch *output_data;
244 static ulg output_ptr;
245 static ulg bytes_out;
246 
247 static void error(char *m);
248 
249 static void putstr(const char *);
250 
251 extern int end;
252 static ulg free_mem_ptr;
253 static ulg free_mem_end_ptr;
254 
255 #ifdef STANDALONE_DEBUG
256 #define NO_INFLATE_MALLOC
257 #endif
258 
259 #define ARCH_HAS_DECOMP_WDOG
260 
261 #include "../../../../lib/inflate.c"
262 
263 /* ===========================================================================
264  * Fill the input buffer. This is called only when the buffer is empty
265  * and at least one byte is really needed.
266  */
267 int fill_inbuf(void)
268 {
269         if (insize != 0)
270                 error("ran out of input data");
271 
272         inbuf = input_data;
273         insize = &input_data_end[0] - &input_data[0];
274 
275         inptr = 1;
276         return inbuf[0];
277 }
278 
279 /* ===========================================================================
280  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
281  * (Used for the decompressed data only.)
282  */
283 void flush_window(void)
284 {
285         ulg c = crc;
286         unsigned n;
287         uch *in, *out, ch;
288 
289         in = window;
290         out = &output_data[output_ptr];
291         for (n = 0; n < outcnt; n++) {
292                 ch = *out++ = *in++;
293                 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
294         }
295         crc = c;
296         bytes_out += (ulg)outcnt;
297         output_ptr += (ulg)outcnt;
298         outcnt = 0;
299         putstr(".");
300 }
301 
302 #ifndef arch_error
303 #define arch_error(x)
304 #endif
305 
306 static void error(char *x)
307 {
308         arch_error(x);
309 
310         putstr("\n\n");
311         putstr(x);
312         putstr("\n\n -- System halted");
313 
314         while(1);       /* Halt */
315 }
316 
317 #ifndef STANDALONE_DEBUG
318 
319 ulg
320 decompress_kernel(ulg output_start, ulg free_mem_ptr_p, ulg free_mem_ptr_end_p,
321                   int arch_id)
322 {
323         output_data             = (uch *)output_start;  /* Points to kernel start */
324         free_mem_ptr            = free_mem_ptr_p;
325         free_mem_end_ptr        = free_mem_ptr_end_p;
326         __machine_arch_type     = arch_id;
327 
328         arch_decomp_setup();
329 
330         makecrc();
331         putstr("Uncompressing Linux...");
332         gunzip();
333         putstr(" done, booting the kernel.\n");
334         return output_ptr;
335 }
336 #else
337 
338 char output_buffer[1500*1024];
339 
340 int main()
341 {
342         output_data = output_buffer;
343 
344         makecrc();
345         putstr("Uncompressing Linux...");
346         gunzip();
347         putstr("done.\n");
348         return 0;
349 }
350 #endif
351         
352 
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