armsrc/start.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) Jonathan Westhues, Mar 2006
   3 // Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
   4 //
   5 // This program is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // See LICENSE.txt for the text of the license.
  16 //-----------------------------------------------------------------------------
  17 // Just vector to AppMain(). This is in its own file so that I can place it
  18 // with the linker script.
  19 //-----------------------------------------------------------------------------
  20
  21 #ifndef __START_H
  22 #define __START_H
  23
  24 #include "proxmark3_arm.h"
  25 #include "appmain.h"
  26 #ifdef WITH_COMPRESSION
  27 #include "lz4.h"
  28 #endif
  29 #include "BigBuf.h"
  30 #include "string.h"
  31 #include "ticks.h"
  32
  33 extern common_area_t g_common_area;
  34 extern uint32_t __data_src_start__[], __data_start__[], __data_end__[], __bss_start__[], __bss_end__[];
  35
  36 #ifdef WITH_COMPRESSION
  37 static void uncompress_data_section(void) {
  38     int avail_in;
  39     memcpy(&avail_in, __data_src_start__, sizeof(int));
  40     int avail_out = (uint32_t)__data_end__ - (uint32_t)__data_start__;  // uncompressed size. Correct.
  41     // uncompress data segment to RAM
  42     char *p = (char *)__data_src_start__;
  43     int res = LZ4_decompress_safe(p + 4, (char *)__data_start__, avail_in, avail_out);
  44     if (res < 0) {
  45         while (true) {
  46             LED_A_INV();
  47             LED_B_INV();
  48             LED_C_INV();
  49             LED_D_INV();
  50             SpinDelay(200);
  51         }
  52     }
  53     // save the size of the compressed data section
  54     g_common_area.arg1 = avail_in;
  55 }
  56 #endif
  57
  58 void __attribute__((section(".startos"))) Vector(void);
  59 void Vector(void) {
  60     /* Stack should have been set up by the bootloader */
  61
  62     if (g_common_area.magic != COMMON_AREA_MAGIC || g_common_area.version != 1) {
  63         /* Initialize common area */
  64         memset(&g_common_area, 0, sizeof(g_common_area));
  65         g_common_area.magic = COMMON_AREA_MAGIC;
  66         g_common_area.version = 1;
  67     }
  68     g_common_area.flags.osimage_present = 1;
  69
  70     /* Set up data segment: Copy from flash to ram */
  71 #ifndef WITH_COMPRESSION
  72     uint32_t *data_src = __data_src_start__;
  73     uint32_t *data_dst = __data_start__;
  74     while (data_dst < __data_end__) *data_dst++ = *data_src++;
  75 #else
  76     uncompress_data_section();
  77 #endif
  78
  79     /* Set up (that is: clear) BSS. */
  80     uint32_t *bss_dst = __bss_start__;
  81     while (bss_dst < __bss_end__) *bss_dst++ = 0;
  82
  83     AppMain();
  84 }
  85 #endif