From 2fe74fa9662f8df51e6ef18227089f54cc07e16a Mon Sep 17 00:00:00 2001 From: Sam Ravnborg Date: Tue, 4 Jan 2011 11:39:10 +0000 Subject: [PATCH] sparc: refactor piggy_32.c Refactoring to increase readability (a little). - sort includes - spaces around operators - small helpers introduced - added a few comments Signed-off-by: Sam Ravnborg Signed-off-by: David S. Miller --- arch/sparc/boot/piggyback_32.c | 142 +++++++++++++++++++++++++++++------------ 1 file changed, 102 insertions(+), 40 deletions(-) diff --git a/arch/sparc/boot/piggyback_32.c b/arch/sparc/boot/piggyback_32.c index ac944ae..cfd95ec 100644 --- a/arch/sparc/boot/piggyback_32.c +++ b/arch/sparc/boot/piggyback_32.c @@ -9,7 +9,7 @@ it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. - + This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the @@ -18,15 +18,16 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - -#include + +#include +#include #include +#include #include #include #include -#include -#include -#include +#include + #include #include @@ -35,16 +36,19 @@ * as PROM looks for a.out image only. */ +/* read two bytes as big endian */ static unsigned short ld2(char *p) { return (p[0] << 8) | p[1]; } +/* read 4 bytes as big endian */ static unsigned int ld4(char *p) { return (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]; } +/* save 4 bytes as big endian */ static void st4(char *p, unsigned int x) { p[0] = x >> 24; @@ -53,6 +57,12 @@ static void st4(char *p, unsigned int x) p[3] = x; } +static void die(const char *str) +{ + perror(str); + exit(1); +} + static void usage(void) { /* fs_img.gz is an image of initial ramdisk. */ @@ -61,10 +71,57 @@ static void usage(void) exit(1); } -static void die(char *str) +static int start_line(const char *line) { - perror (str); - exit(1); + if (strcmp(line + 8, " T start\n") == 0) + return 1; + else if (strcmp(line + 16, " T start\n") == 0) + return 1; + return 0; +} + +static int end_line(const char *line) +{ + if (strcmp(line + 8, " A _end\n") == 0) + return 1; + else if (strcmp (line + 16, " A _end\n") == 0) + return 1; + return 0; +} + +/* + * Find address for start and end in System.map. + * The file looks like this: + * f0004000 T start + * f0379f79 A _end + * 1234567890123456 + * ^coloumn 1 + * There is support for 64 bit addresses too. + * + * Return 0 if either start or end is not found + */ +static int get_start_end(const char *filename, unsigned int *start, unsigned int *end) +{ + FILE *map; + char buffer[1024]; + + *start = 0; + *end = 0; + map = fopen(filename, "r"); + if (!map) + die(filename); + while (fgets(buffer, 1024, map)) { + if (start_line(buffer)) + *start = strtoul(buffer, NULL, 16); + else if (end_line(buffer)) + *end = strtoul(buffer, NULL, 16); + } + fclose (map); + + if (*start == 0 || *end == 0) + return 0; + + return 1; } int main(int argc,char **argv) @@ -72,33 +129,29 @@ int main(int argc,char **argv) static char aout_magic[] = { 0x01, 0x03, 0x01, 0x07 }; char buffer[1024], *q, *r; unsigned int i, j, k, start, end, offset; - FILE *map; struct stat s; int image, tail; - if (argc != 4) usage(); - start = end = 0; - if (stat (argv[3], &s) < 0) die (argv[3]); - map = fopen (argv[2], "r"); - if (!map) die(argv[2]); - while (fgets (buffer, 1024, map)) { - if (!strcmp (buffer + 8, " T start\n") || !strcmp (buffer + 16, " T start\n")) - start = strtoul (buffer, NULL, 16); - else if (!strcmp (buffer + 8, " A _end\n") || !strcmp (buffer + 16, " A _end\n")) - end = strtoul (buffer, NULL, 16); - } - fclose (map); - if (!start || !end) { - fprintf (stderr, "Could not determine start and end from System.map\n"); + if (argc != 4) + usage(); + if (stat (argv[3], &s) < 0) + die(argv[3]); + + if (!get_start_end(argv[2], &start, &end)) { + fprintf (stderr, "Could not determine start and end from %s\n", argv[2]); exit(1); } - if ((image = open(argv[1],O_RDWR)) < 0) die(argv[1]); - if (read(image,buffer,512) != 512) die(argv[1]); + if ((image = open(argv[1], O_RDWR)) < 0) + die(argv[1]); + if (read(image, buffer, 512) != 512) + die(argv[1]); if (memcmp (buffer, "\177ELF", 4) == 0) { q = buffer + ld4(buffer + 28); i = ld4(q + 4) + ld4(buffer + 24) - ld4(q + 8); - if (lseek(image,i,0) < 0) die("lseek"); - if (read(image,buffer,512) != 512) die(argv[1]); + if (lseek(image, i, 0) < 0) + die("lseek"); + if (read(image, buffer, 512) != 512) + die(argv[1]); j = 0; } else if (memcmp(buffer, aout_magic, 4) == 0) { i = j = 32; @@ -107,9 +160,11 @@ int main(int argc,char **argv) exit(1); } k = i; - i += (ld2(buffer + j + 2)<<2) - 512; - if (lseek(image,i,0) < 0) die("lseek"); - if (read(image,buffer,1024) != 1024) die(argv[1]); + i += (ld2(buffer + j + 2) << 2) - 512; + if (lseek(image, i, 0) < 0) + die("lseek"); + if (read(image, buffer, 1024) != 1024) + die(argv[1]); for (q = buffer, r = q + 512; q < r; q += 4) { if (*q == 'H' && q[1] == 'd' && q[2] == 'r' && q[3] == 'S') break; @@ -119,19 +174,26 @@ int main(int argc,char **argv) exit(1); } offset = i + (q - buffer) + 10; - if (lseek(image, offset, 0) < 0) die ("lseek"); + if (lseek(image, offset, 0) < 0) + die("lseek"); st4(buffer, 0); st4(buffer + 4, 0x01000000); st4(buffer + 8, (end + 32 + 4095) & ~4095); st4(buffer + 12, s.st_size); - if (write(image,buffer+2,14) != 14) die (argv[1]); - if (lseek(image, k - start + ((end + 32 + 4095) & ~4095), 0) < 0) die ("lseek"); - if ((tail = open(argv[3],O_RDONLY)) < 0) die(argv[3]); - while ((i = read (tail,buffer,1024)) > 0) - if (write(image,buffer,i) != i) die (argv[1]); - if (close(image) < 0) die("close"); - if (close(tail) < 0) die("close"); - return 0; + if (write(image, buffer + 2, 14) != 14) + die(argv[1]); + if (lseek(image, k - start + ((end + 32 + 4095) & ~4095), 0) < 0) + die("lseek"); + if ((tail = open(argv[3],O_RDONLY)) < 0) + die(argv[3]); + while ((i = read (tail, buffer, 1024)) > 0) + if (write(image, buffer, i) != i) + die(argv[1]); + if (close(image) < 0) + die("close"); + if (close(tail) < 0) + die("close"); + return 0; } -- 2.7.4