target/linux/bmips/image/lzma-loader/src/loader.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * LZMA compressed kernel loader for Atheros AR7XXX/AR9XXX based boards
   4  *
   5  * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
   6  *
   7  * Some parts of this code was based on the OpenWrt specific lzma-loader
   8  * for the BCM47xx and ADM5120 based boards:
   9  *      Copyright (C) 2004 Manuel Novoa III (mjn3@codepoet.org)
  10  *      Copyright (C) 2005 Mineharu Takahara <mtakahar@yahoo.com>
  11  *      Copyright (C) 2005 by Oleg I. Vdovikin <oleg@cs.msu.su>
  12  *
  13  * The image_header structure has been taken from the U-Boot project.
  14  *      (C) Copyright 2008 Semihalf
  15  *      (C) Copyright 2000-2005
  16  *      Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  17  */
  18
  19 #include <stddef.h>
  20 #include <stdint.h>
  21
  22 #include "config.h"
  23 #include "cache.h"
  24 #include "printf.h"
  25 #include "LzmaDecode.h"
  26
  27 #define KSEG0                   0x80000000
  28 #define KSEG1                   0xa0000000
  29
  30 #define KSEG1ADDR(a)            ((((unsigned)(a)) & 0x1fffffffU) | KSEG1)
  31
  32 #undef LZMA_DEBUG
  33
  34 #ifdef LZMA_DEBUG
  35 #  define DBG(f, a...)  printf(f, ## a)
  36 #else
  37 #  define DBG(f, a...)  do {} while (0)
  38 #endif
  39
  40 /* beyond the image end, size not known in advance */
  41 extern unsigned char workspace[];
  42
  43
  44 static CLzmaDecoderState lzma_state;
  45 static unsigned char *lzma_data;
  46 static unsigned long lzma_datasize;
  47 static unsigned long lzma_outsize;
  48 static unsigned long kernel_la;
  49
  50 static void halt(void)
  51 {
  52         printf("\nSystem halted!\n");
  53         for(;;);
  54 }
  55
  56 static __inline__ unsigned char lzma_get_byte(void)
  57 {
  58         unsigned char c;
  59
  60         lzma_datasize--;
  61         c = *lzma_data++;
  62
  63         return c;
  64 }
  65
  66 static int lzma_init_props(void)
  67 {
  68         unsigned char props[LZMA_PROPERTIES_SIZE];
  69         int res;
  70         int i;
  71
  72         /* read lzma properties */
  73         for (i = 0; i < LZMA_PROPERTIES_SIZE; i++)
  74                 props[i] = lzma_get_byte();
  75
  76         /* read the lower half of uncompressed size in the header */
  77         lzma_outsize = ((SizeT) lzma_get_byte()) +
  78                        ((SizeT) lzma_get_byte() << 8) +
  79                        ((SizeT) lzma_get_byte() << 16) +
  80                        ((SizeT) lzma_get_byte() << 24);
  81
  82         /* skip rest of the header (upper half of uncompressed size) */
  83         for (i = 0; i < 4; i++)
  84                 lzma_get_byte();
  85
  86         res = LzmaDecodeProperties(&lzma_state.Properties, props,
  87                                         LZMA_PROPERTIES_SIZE);
  88         return res;
  89 }
  90
  91 static int lzma_decompress(unsigned char *outStream)
  92 {
  93         SizeT ip, op;
  94         int ret;
  95
  96         lzma_state.Probs = (CProb *) workspace;
  97
  98         ret = LzmaDecode(&lzma_state, lzma_data, lzma_datasize, &ip, outStream,
  99                          lzma_outsize, &op);
 100
 101         if (ret != LZMA_RESULT_OK) {
 102                 int i;
 103
 104                 DBG("LzmaDecode error %d at %08x, osize:%d ip:%d op:%d\n",
 105                     ret, lzma_data + ip, lzma_outsize, ip, op);
 106
 107                 for (i = 0; i < 16; i++)
 108                         DBG("%02x ", lzma_data[ip + i]);
 109
 110                 DBG("\n");
 111         }
 112
 113         return ret;
 114 }
 115
 116 static void lzma_init_data(void)
 117 {
 118         extern unsigned char _lzma_data_start[];
 119         extern unsigned char _lzma_data_end[];
 120
 121         kernel_la = LOADADDR;
 122         lzma_data = _lzma_data_start;
 123         lzma_datasize = _lzma_data_end - _lzma_data_start;
 124 }
 125
 126 void loader_main(unsigned long reg_a0, unsigned long reg_a1,
 127                  unsigned long reg_a2, unsigned long reg_a3)
 128 {
 129         void (*kernel_entry) (unsigned long, unsigned long, unsigned long,
 130                               unsigned long);
 131         int res;
 132
 133         printf("\n\nOpenWrt kernel loader for BMIPS\n");
 134         printf("Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>\n");
 135         printf("Copyright (C) 2014 Jonas Gorski <jogo@openwrt.org>\n");
 136         printf("Copyright (C) 2020 Alvaro Fernandez Rojas <noltari@gmail.com>\n");
 137
 138         lzma_init_data();
 139
 140         res = lzma_init_props();
 141         if (res != LZMA_RESULT_OK) {
 142                 printf("Incorrect LZMA stream properties!\n");
 143                 halt();
 144         }
 145
 146         printf("Decompressing kernel... ");
 147
 148         res = lzma_decompress((unsigned char *) kernel_la);
 149         if (res != LZMA_RESULT_OK) {
 150                 printf("failed, ");
 151                 switch (res) {
 152                 case LZMA_RESULT_DATA_ERROR:
 153                         printf("data error!\n");
 154                         break;
 155                 default:
 156                         printf("unknown error %d!\n", res);
 157                 }
 158                 halt();
 159         } else {
 160                 printf("done!\n");
 161         }
 162
 163         flush_cache(kernel_la, lzma_outsize);
 164
 165         printf("Starting kernel at %08x...\n\n", kernel_la);
 166
 167         kernel_entry = (void *) kernel_la;
 168         kernel_entry(reg_a0, reg_a1, reg_a2, reg_a3);
 169 }