1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Convert a logo in ASCII PNM format to C source suitable for inclusion in
4 * the Linux kernel
5 *
6 * (C) Copyright 2001-2003 by Geert Uytterhoeven <geert@linux-m68k.org>
7 */
8
9 #include <ctype.h>
10 #include <errno.h>
11 #include <stdarg.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <unistd.h>
16
17
18 static const char *programname;
19 static const char *filename;
20 static const char *logoname = "linux_logo";
21 static const char *outputname;
22 static FILE *out;
23
24
25 #define LINUX_LOGO_MONO 1 /* monochrome black/white */
26 #define LINUX_LOGO_VGA16 2 /* 16 colors VGA text palette */
27 #define LINUX_LOGO_CLUT224 3 /* 224 colors */
28 #define LINUX_LOGO_GRAY256 4 /* 256 levels grayscale */
29
30 static const char *logo_types[LINUX_LOGO_GRAY256+1] = {
31 [LINUX_LOGO_MONO] = "LINUX_LOGO_MONO",
32 [LINUX_LOGO_VGA16] = "LINUX_LOGO_VGA16",
33 [LINUX_LOGO_CLUT224] = "LINUX_LOGO_CLUT224",
34 [LINUX_LOGO_GRAY256] = "LINUX_LOGO_GRAY256"
35 };
36
37 #define MAX_LINUX_LOGO_COLORS 224
38
39 struct color {
40 unsigned char red;
41 unsigned char green;
42 unsigned char blue;
43 };
44
45 static const struct color clut_vga16[16] = {
46 { 0x00, 0x00, 0x00 },
47 { 0x00, 0x00, 0xaa },
48 { 0x00, 0xaa, 0x00 },
49 { 0x00, 0xaa, 0xaa },
50 { 0xaa, 0x00, 0x00 },
51 { 0xaa, 0x00, 0xaa },
52 { 0xaa, 0x55, 0x00 },
53 { 0xaa, 0xaa, 0xaa },
54 { 0x55, 0x55, 0x55 },
55 { 0x55, 0x55, 0xff },
56 { 0x55, 0xff, 0x55 },
57 { 0x55, 0xff, 0xff },
58 { 0xff, 0x55, 0x55 },
59 { 0xff, 0x55, 0xff },
60 { 0xff, 0xff, 0x55 },
61 { 0xff, 0xff, 0xff },
62 };
63
64
65 static int logo_type = LINUX_LOGO_CLUT224;
66 static unsigned int logo_width;
67 static unsigned int logo_height;
68 static struct color **logo_data;
69 static struct color logo_clut[MAX_LINUX_LOGO_COLORS];
70 static unsigned int logo_clutsize;
71 static int is_plain_pbm = 0;
72
73 static void die(const char *fmt, ...)
74 __attribute__((noreturn)) __attribute((format (printf, 1, 2)));
75 static void usage(void) __attribute((noreturn));
76
77
get_number(FILE * fp)78 static unsigned int get_number(FILE *fp)
79 {
80 int c, val;
81
82 /* Skip leading whitespace */
83 do {
84 c = fgetc(fp);
85 if (c == EOF)
86 die("%s: end of file\n", filename);
87 if (c == '#') {
88 /* Ignore comments 'till end of line */
89 do {
90 c = fgetc(fp);
91 if (c == EOF)
92 die("%s: end of file\n", filename);
93 } while (c != '\n');
94 }
95 } while (isspace(c));
96
97 /* Parse decimal number */
98 val = 0;
99 while (isdigit(c)) {
100 val = 10*val+c-'0';
101 /* some PBM are 'broken'; GiMP for example exports a PBM without space
102 * between the digits. This is Ok cause we know a PBM can only have a '1'
103 * or a '0' for the digit.
104 */
105 if (is_plain_pbm)
106 break;
107 c = fgetc(fp);
108 if (c == EOF)
109 die("%s: end of file\n", filename);
110 }
111 return val;
112 }
113
get_number255(FILE * fp,unsigned int maxval)114 static unsigned int get_number255(FILE *fp, unsigned int maxval)
115 {
116 unsigned int val = get_number(fp);
117
118 return (255*val+maxval/2)/maxval;
119 }
120
read_image(void)121 static void read_image(void)
122 {
123 FILE *fp;
124 unsigned int i, j;
125 int magic;
126 unsigned int maxval;
127
128 /* open image file */
129 fp = fopen(filename, "r");
130 if (!fp)
131 die("Cannot open file %s: %s\n", filename, strerror(errno));
132
133 /* check file type and read file header */
134 magic = fgetc(fp);
135 if (magic != 'P')
136 die("%s is not a PNM file\n", filename);
137 magic = fgetc(fp);
138 switch (magic) {
139 case '1':
140 case '2':
141 case '3':
142 /* Plain PBM/PGM/PPM */
143 break;
144
145 case '4':
146 case '5':
147 case '6':
148 /* Binary PBM/PGM/PPM */
149 die("%s: Binary PNM is not supported\n"
150 "Use pnmnoraw(1) to convert it to ASCII PNM\n", filename);
151
152 default:
153 die("%s is not a PNM file\n", filename);
154 }
155 logo_width = get_number(fp);
156 logo_height = get_number(fp);
157
158 /* allocate image data */
159 logo_data = (struct color **)malloc(logo_height*sizeof(struct color *));
160 if (!logo_data)
161 die("%s\n", strerror(errno));
162 for (i = 0; i < logo_height; i++) {
163 logo_data[i] = malloc(logo_width*sizeof(struct color));
164 if (!logo_data[i])
165 die("%s\n", strerror(errno));
166 }
167
168 /* read image data */
169 switch (magic) {
170 case '1':
171 /* Plain PBM */
172 is_plain_pbm = 1;
173 for (i = 0; i < logo_height; i++)
174 for (j = 0; j < logo_width; j++)
175 logo_data[i][j].red = logo_data[i][j].green =
176 logo_data[i][j].blue = 255*(1-get_number(fp));
177 break;
178
179 case '2':
180 /* Plain PGM */
181 maxval = get_number(fp);
182 for (i = 0; i < logo_height; i++)
183 for (j = 0; j < logo_width; j++)
184 logo_data[i][j].red = logo_data[i][j].green =
185 logo_data[i][j].blue = get_number255(fp, maxval);
186 break;
187
188 case '3':
189 /* Plain PPM */
190 maxval = get_number(fp);
191 for (i = 0; i < logo_height; i++)
192 for (j = 0; j < logo_width; j++) {
193 logo_data[i][j].red = get_number255(fp, maxval);
194 logo_data[i][j].green = get_number255(fp, maxval);
195 logo_data[i][j].blue = get_number255(fp, maxval);
196 }
197 break;
198 }
199
200 /* close file */
201 fclose(fp);
202 }
203
is_black(struct color c)204 static inline int is_black(struct color c)
205 {
206 return c.red == 0 && c.green == 0 && c.blue == 0;
207 }
208
is_white(struct color c)209 static inline int is_white(struct color c)
210 {
211 return c.red == 255 && c.green == 255 && c.blue == 255;
212 }
213
is_gray(struct color c)214 static inline int is_gray(struct color c)
215 {
216 return c.red == c.green && c.red == c.blue;
217 }
218
is_equal(struct color c1,struct color c2)219 static inline int is_equal(struct color c1, struct color c2)
220 {
221 return c1.red == c2.red && c1.green == c2.green && c1.blue == c2.blue;
222 }
223
write_header(void)224 static void write_header(void)
225 {
226 /* open logo file */
227 if (outputname) {
228 out = fopen(outputname, "w");
229 if (!out)
230 die("Cannot create file %s: %s\n", outputname, strerror(errno));
231 } else {
232 out = stdout;
233 }
234
235 fputs("/*\n", out);
236 fputs(" * DO NOT EDIT THIS FILE!\n", out);
237 fputs(" *\n", out);
238 fprintf(out, " * Linux logo %s\n", logoname);
239 fputs(" */\n\n", out);
240 fputs("#include <linux/linux_logo.h>\n\n", out);
241 fprintf(out, "static const unsigned char %s_data[] __initconst = {\n",
242 logoname);
243 }
244
write_footer(void)245 static void write_footer(void)
246 {
247 fputs("\n};\n\n", out);
248 fprintf(out, "const struct linux_logo %s __initconst = {\n", logoname);
249 fprintf(out, "\t.type\t\t= %s,\n", logo_types[logo_type]);
250 fprintf(out, "\t.width\t\t= %u,\n", logo_width);
251 fprintf(out, "\t.height\t\t= %u,\n", logo_height);
252 if (logo_type == LINUX_LOGO_CLUT224) {
253 fprintf(out, "\t.clutsize\t= %u,\n", logo_clutsize);
254 fprintf(out, "\t.clut\t\t= %s_clut,\n", logoname);
255 }
256 fprintf(out, "\t.data\t\t= %s_data\n", logoname);
257 fputs("};\n\n", out);
258
259 /* close logo file */
260 if (outputname)
261 fclose(out);
262 }
263
264 static int write_hex_cnt;
265
write_hex(unsigned char byte)266 static void write_hex(unsigned char byte)
267 {
268 if (write_hex_cnt % 12)
269 fprintf(out, ", 0x%02x", byte);
270 else if (write_hex_cnt)
271 fprintf(out, ",\n\t0x%02x", byte);
272 else
273 fprintf(out, "\t0x%02x", byte);
274 write_hex_cnt++;
275 }
276
write_logo_mono(void)277 static void write_logo_mono(void)
278 {
279 unsigned int i, j;
280 unsigned char val, bit;
281
282 /* validate image */
283 for (i = 0; i < logo_height; i++)
284 for (j = 0; j < logo_width; j++)
285 if (!is_black(logo_data[i][j]) && !is_white(logo_data[i][j]))
286 die("Image must be monochrome\n");
287
288 /* write file header */
289 write_header();
290
291 /* write logo data */
292 for (i = 0; i < logo_height; i++) {
293 for (j = 0; j < logo_width;) {
294 for (val = 0, bit = 0x80; bit && j < logo_width; j++, bit >>= 1)
295 if (logo_data[i][j].red)
296 val |= bit;
297 write_hex(val);
298 }
299 }
300
301 /* write logo structure and file footer */
302 write_footer();
303 }
304
write_logo_vga16(void)305 static void write_logo_vga16(void)
306 {
307 unsigned int i, j, k;
308 unsigned char val;
309
310 /* validate image */
311 for (i = 0; i < logo_height; i++)
312 for (j = 0; j < logo_width; j++) {
313 for (k = 0; k < 16; k++)
314 if (is_equal(logo_data[i][j], clut_vga16[k]))
315 break;
316 if (k == 16)
317 die("Image must use the 16 console colors only\n"
318 "Use ppmquant(1) -map clut_vga16.ppm to reduce the number "
319 "of colors\n");
320 }
321
322 /* write file header */
323 write_header();
324
325 /* write logo data */
326 for (i = 0; i < logo_height; i++)
327 for (j = 0; j < logo_width; j++) {
328 for (k = 0; k < 16; k++)
329 if (is_equal(logo_data[i][j], clut_vga16[k]))
330 break;
331 val = k<<4;
332 if (++j < logo_width) {
333 for (k = 0; k < 16; k++)
334 if (is_equal(logo_data[i][j], clut_vga16[k]))
335 break;
336 val |= k;
337 }
338 write_hex(val);
339 }
340
341 /* write logo structure and file footer */
342 write_footer();
343 }
344
write_logo_clut224(void)345 static void write_logo_clut224(void)
346 {
347 unsigned int i, j, k;
348
349 /* validate image */
350 for (i = 0; i < logo_height; i++)
351 for (j = 0; j < logo_width; j++) {
352 for (k = 0; k < logo_clutsize; k++)
353 if (is_equal(logo_data[i][j], logo_clut[k]))
354 break;
355 if (k == logo_clutsize) {
356 if (logo_clutsize == MAX_LINUX_LOGO_COLORS)
357 die("Image has more than %d colors\n"
358 "Use ppmquant(1) to reduce the number of colors\n",
359 MAX_LINUX_LOGO_COLORS);
360 logo_clut[logo_clutsize++] = logo_data[i][j];
361 }
362 }
363
364 /* write file header */
365 write_header();
366
367 /* write logo data */
368 for (i = 0; i < logo_height; i++)
369 for (j = 0; j < logo_width; j++) {
370 for (k = 0; k < logo_clutsize; k++)
371 if (is_equal(logo_data[i][j], logo_clut[k]))
372 break;
373 write_hex(k+32);
374 }
375 fputs("\n};\n\n", out);
376
377 /* write logo clut */
378 fprintf(out, "static const unsigned char %s_clut[] __initconst = {\n",
379 logoname);
380 write_hex_cnt = 0;
381 for (i = 0; i < logo_clutsize; i++) {
382 write_hex(logo_clut[i].red);
383 write_hex(logo_clut[i].green);
384 write_hex(logo_clut[i].blue);
385 }
386
387 /* write logo structure and file footer */
388 write_footer();
389 }
390
write_logo_gray256(void)391 static void write_logo_gray256(void)
392 {
393 unsigned int i, j;
394
395 /* validate image */
396 for (i = 0; i < logo_height; i++)
397 for (j = 0; j < logo_width; j++)
398 if (!is_gray(logo_data[i][j]))
399 die("Image must be grayscale\n");
400
401 /* write file header */
402 write_header();
403
404 /* write logo data */
405 for (i = 0; i < logo_height; i++)
406 for (j = 0; j < logo_width; j++)
407 write_hex(logo_data[i][j].red);
408
409 /* write logo structure and file footer */
410 write_footer();
411 }
412
die(const char * fmt,...)413 static void die(const char *fmt, ...)
414 {
415 va_list ap;
416
417 va_start(ap, fmt);
418 vfprintf(stderr, fmt, ap);
419 va_end(ap);
420
421 exit(1);
422 }
423
usage(void)424 static void usage(void)
425 {
426 die("\n"
427 "Usage: %s [options] <filename>\n"
428 "\n"
429 "Valid options:\n"
430 " -h : display this usage information\n"
431 " -n <name> : specify logo name (default: linux_logo)\n"
432 " -o <output> : output to file <output> instead of stdout\n"
433 " -t <type> : specify logo type, one of\n"
434 " mono : monochrome black/white\n"
435 " vga16 : 16 colors VGA text palette\n"
436 " clut224 : 224 colors (default)\n"
437 " gray256 : 256 levels grayscale\n"
438 "\n", programname);
439 }
440
main(int argc,char * argv[])441 int main(int argc, char *argv[])
442 {
443 int opt;
444
445 programname = argv[0];
446
447 opterr = 0;
448 while (1) {
449 opt = getopt(argc, argv, "hn:o:t:");
450 if (opt == -1)
451 break;
452
453 switch (opt) {
454 case 'h':
455 usage();
456 break;
457
458 case 'n':
459 logoname = optarg;
460 break;
461
462 case 'o':
463 outputname = optarg;
464 break;
465
466 case 't':
467 if (!strcmp(optarg, "mono"))
468 logo_type = LINUX_LOGO_MONO;
469 else if (!strcmp(optarg, "vga16"))
470 logo_type = LINUX_LOGO_VGA16;
471 else if (!strcmp(optarg, "clut224"))
472 logo_type = LINUX_LOGO_CLUT224;
473 else if (!strcmp(optarg, "gray256"))
474 logo_type = LINUX_LOGO_GRAY256;
475 else
476 usage();
477 break;
478
479 default:
480 usage();
481 break;
482 }
483 }
484 if (optind != argc-1)
485 usage();
486
487 filename = argv[optind];
488
489 read_image();
490 switch (logo_type) {
491 case LINUX_LOGO_MONO:
492 write_logo_mono();
493 break;
494
495 case LINUX_LOGO_VGA16:
496 write_logo_vga16();
497 break;
498
499 case LINUX_LOGO_CLUT224:
500 write_logo_clut224();
501 break;
502
503 case LINUX_LOGO_GRAY256:
504 write_logo_gray256();
505 break;
506 }
507 exit(0);
508 }
509