armsrc/start.c

   1 //-----------------------------------------------------------------------------
   2 // Jonathan Westhues, Mar 2006
   3 //
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //-----------------------------------------------------------------------------
   8 // Just vector to AppMain(). This is in its own file so that I can place it
   9 // with the linker script.
  10 //-----------------------------------------------------------------------------
  11
  12 #ifndef __START_H
  13 #define __START_H
  14
  15 #include "proxmark3_arm.h"
  16 #include "appmain.h"
  17 #ifndef WITH_NO_COMPRESSION
  18 #include "lz4.h"
  19 #endif
  20 #include "BigBuf.h"
  21 #include "string.h"
  22
  23 extern struct common_area common_area;
  24 extern uint32_t __data_src_start__[], __data_start__[], __data_end__[], __bss_start__[], __bss_end__[];
  25
  26 #ifndef WITH_NO_COMPRESSION
  27 static void uncompress_data_section(void) {
  28     int avail_in;
  29     memcpy(&avail_in, __data_src_start__, sizeof(int));
  30     int avail_out = (uint32_t)__data_end__ - (uint32_t)__data_start__;  // uncompressed size. Correct.
  31     // uncompress data segment to RAM
  32     char *p = (char *)__data_src_start__;
  33     int res = LZ4_decompress_safe(p + 4, (char *)__data_start__, avail_in, avail_out);
  34
  35     if (res < 0)
  36         return;
  37     // save the size of the compressed data section
  38     common_area.arg1 = avail_in;
  39 }
  40 #endif
  41
  42 void __attribute__((section(".startos"))) Vector(void);
  43 void Vector(void) {
  44     /* Stack should have been set up by the bootloader */
  45
  46     if (common_area.magic != COMMON_AREA_MAGIC || common_area.version != 1) {
  47         /* Initialize common area */
  48         memset(&common_area, 0, sizeof(common_area));
  49         common_area.magic = COMMON_AREA_MAGIC;
  50         common_area.version = 1;
  51     }
  52     common_area.flags.osimage_present = 1;
  53
  54     /* Set up data segment: Copy from flash to ram */
  55 #ifdef WITH_NO_COMPRESSION
  56     uint32_t *data_src = __data_src_start__;
  57     uint32_t *data_dst = __data_start__;
  58     while (data_dst < __data_end__) *data_dst++ = *data_src++;
  59 #else
  60     uncompress_data_section();
  61 #endif
  62
  63     /* Set up (that is: clear) BSS. */
  64     uint32_t *bss_dst = __bss_start__;
  65     while (bss_dst < __bss_end__) *bss_dst++ = 0;
  66
  67     AppMain();
  68 }
  69 #endif