payloads/libpayload/libc/lib.c

   1 /*
   2  *
   3  * Copyright (C) 2008 Uwe Hermann <uwe@hermann-uwe.de>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <assert.h>
  30 #include <libpayload.h>
  31
  32 /*
  33  * Convert a number in BCD format to decimal.
  34  *
  35  * @param b The BCD number.
  36  * @return The given BCD number in decimal format.
  37  */
  38 int bcd2dec(int b)
  39 {
  40         return ((b >> 4) & 0x0f) * 10 + (b & 0x0f);
  41 }
  42
  43 /*
  44  * Convert a number in decimal format into the BCD format.
  45  *
  46  * @param d The decimal number.
  47  * @return The given decimal number in BCD format.
  48  */
  49 int dec2bcd(int d)
  50 {
  51         return ((d / 10) << 4) | (d % 10);
  52 }
  53
  54 /**
  55  * Return the absolute value of the specified integer.
  56  *
  57  * @param j The integer of which we want to know the absolute value.
  58  * @return The absolute value of the specified integer.
  59  */
  60 int abs(int j)
  61 {
  62         return (j >= 0 ? j : -j);
  63 }
  64
  65 long int labs(long int j)
  66 {
  67         return (j >= 0 ? j : -j);
  68 }
  69
  70 long long int llabs(long long int j)
  71 {
  72         return (j >= 0 ? j : -j);
  73 }
  74
  75 /**
  76  * Given a 4-bit value, return the ASCII hex representation of it.
  77  *
  78  * @param b A 4-bit value which shall be converted to ASCII hex.
  79  * @return The ASCII hex representation of the specified 4-bit value.
  80  *         Returned hex-characters will always be lower-case (a-f, not A-F).
  81  */
  82 u8 bin2hex(u8 b)
  83 {
  84         return (b < 10) ? '0' + b : 'a' + (b - 10);
  85 }
  86
  87 /**
  88  * Given an ASCII hex input character, return its integer value.
  89  *
  90  * For example, the input value '6' will be converted to 6, 'a'/'A' will
  91  * be converted to 10, 'f'/'F' will be converted to 15, and so on.
  92  *
  93  * The return value for invalid input characters is 0.
  94  *
  95  * @param h The input byte in ASCII hex format.
  96  * @return The integer value of the specified ASCII hex byte.
  97  */
  98 u8 hex2bin(u8 h)
  99 {
 100         return (('0' <= h && h <= '9') ? (h - '0') : \
 101                 ('A' <= h && h <= 'F') ? (h - 'A' + 10) : \
 102                 ('a' <= h && h <= 'f') ? (h - 'a' + 10) : 0);
 103 }
 104
 105 /**
 106  * Enters HALT state, after printing msg
 107  *
 108  * @param msg message to print
 109  */
 110 void fatal(const char *msg)
 111 {
 112         fprintf(stderr, "%s",msg);
 113         halt();
 114 }
 115
 116 void exit(int status)
 117 {
 118         printf("exited with status %d\n", status);
 119         halt();
 120 }
 121
 122 void __noreturn abort(void)
 123 {
 124         halt();
 125 }
 126
 127 int errno;
 128
 129 char *getenv(const char *name)
 130 {
 131         return NULL;
 132 }
 133
 134 /*
 135  * Reads a transfer buffer from 32-bit FIFO registers. fifo_stride is the
 136  * distance in bytes between registers (e.g. pass 4 for a normal array of 32-bit
 137  * registers or 0 to read everything from the same register). fifo_width is
 138  * the amount of bytes read per register (can be 1 through 4).
 139  */
 140 void buffer_from_fifo32(void *buffer, size_t size, void *fifo,
 141                         int fifo_stride, int fifo_width)
 142 {
 143         u8 *p = buffer;
 144         int i, j;
 145
 146         assert(fifo_width > 0 && fifo_width <= sizeof(u32) &&
 147                fifo_stride % sizeof(u32) == 0);
 148
 149         for (i = 0; i < size; i += fifo_width, fifo += fifo_stride) {
 150                 u32 val = read32(fifo);
 151                 for (j = 0; j < MIN(size - i, fifo_width); j++)
 152                         *p++ = (u8)(val >> (j * 8));
 153         }
 154 }
 155
 156 /*
 157  * Version of buffer_to_fifo32() that can prepend a prefix of up to fifo_width
 158  * size to the transfer. This is often useful for protocols where a command word
 159  * precedes the actual payload data. The prefix must be packed in the low-order
 160  * bytes of the 'prefix' u32 parameter and any high-order bytes exceeding prefsz
 161  * must be 0. Note that 'size' counts total bytes written, including 'prefsz'.
 162  */
 163 void buffer_to_fifo32_prefix(const void *buffer, u32 prefix, int prefsz, size_t size,
 164                              void *fifo, int fifo_stride, int fifo_width)
 165 {
 166         const u8 *p = buffer;
 167         int i, j = prefsz;
 168
 169         assert(fifo_width > 0 && fifo_width <= sizeof(u32) &&
 170                fifo_stride % sizeof(u32) == 0 && prefsz <= fifo_width);
 171
 172         uint32_t val = prefix;
 173         for (i = 0; i < size; i += fifo_width, fifo += fifo_stride) {
 174                 for (; j < MIN(size - i, fifo_width); j++)
 175                         val |= *p++ << (j * 8);
 176                 write32(fifo, val);
 177                 val = 0;
 178                 j = 0;
 179         }
 180
 181 }
 182
 183 __weak void reboot(void)
 184 {
 185         fatal("Reboot requested but not implemented\n");
 186 }