1  /* SPDX-License-Identifier: GPL-2.0-only */
  2  
  3  #ifdef __MINGW32__
  4  #include <winsock.h>
  5  #else
  6  #include <arpa/inet.h>
  7  #endif
  8  #include <sys/types.h>
  9  #include <sys/stat.h>
 10  #ifndef __MINGW32__
 11  #include <sys/mman.h>
 12  #endif
 13  #include <stdlib.h>
 14  #include <fcntl.h>
 15  #include <string.h>
 16  #include <stdio.h>
 17  #include "cbfs.h"
 18  #include "common.h"
 19  
 20  #define ALIGN(x,a)              __ALIGN_MASK(x,(typeof(x))(a)-1)
 21  #define __ALIGN_MASK(x,mask)    (((x)+(mask))&~(mask))
 22  
 23  static void *cbfs_mapped;
 24  static void *cbfs_offset;
 25  static void* virt_to_phys(u32 virt)
 26  {
 27  	return cbfs_offset + virt;
 28  }
 29  
 30  #ifdef DEBUG
 31  #define debug(x...) printf(x)
 32  #else
 33  #define debug(x...) while(0) {}
 34  #endif
 35  
 36  static int cbfs_check_magic(struct cbfs_file *file)
 37  {
 38  	return !strcmp(file->magic, CBFS_FILE_MAGIC) ? 1 : 0;
 39  }
 40  
 41  static struct cbfs_header *cbfs_master_header(void)
 42  {
 43  	struct cbfs_header *header;
 44  
 45  	void *ptr = virt_to_phys(*((u32*)virt_to_phys(CBFS_HEADPTR_ADDR)));
 46  	debug("Check CBFS header at %p\n", ptr);
 47  	header = (struct cbfs_header *) ptr;
 48  
 49  	debug("magic is %08x\n", ntohl(header->magic));
 50  	if (ntohl(header->magic) != CBFS_HEADER_MAGIC) {
 51  		printf("ERROR: No valid CBFS header found!\n");
 52  		return NULL;
 53  	}
 54  
 55  	debug("Found CBFS header at %p\n", ptr);
 56  	return header;
 57  }
 58  
 59  struct cbfs_file *cbfs_find(const char *name)
 60  {
 61  	struct cbfs_header *header = cbfs_master_header();
 62  	void *offset;
 63  
 64  	if (header == NULL)
 65  		return NULL;
 66  	offset = virt_to_phys(0 - ntohl(header->romsize) + ntohl(header->offset));
 67  
 68  	int align= ntohl(header->align);
 69  
 70  	while(1) {
 71  		struct cbfs_file *file = (struct cbfs_file *) offset;
 72  		if (!cbfs_check_magic(file)) return NULL;
 73  		debug("Check %s\n", CBFS_NAME(file));
 74  		if (!strcmp(CBFS_NAME(file), name))
 75  			return file;
 76  
 77  		int flen = ntohl(file->len);
 78  		int foffset = ntohl(file->offset);
 79  		debug("CBFS: follow chain: %p + %x + %x + align -> ", offset, foffset, flen);
 80  
 81  		void *oldoffset = offset;
 82  		offset = (void*)ALIGN((uintptr_t)(offset + foffset + flen), align);
 83  		debug("%p\n", (void *)offset);
 84  		if (offset <= oldoffset) return NULL;
 85  
 86  		if (offset < virt_to_phys(0xFFFFFFFF - ntohl(header->romsize)))
 87  			return NULL;
 88  	}
 89  }
 90  
 91  void *cbfs_find_file(const char *name, unsigned int type, unsigned int *len)
 92  {
 93  	struct cbfs_file *file = cbfs_find(name);
 94  
 95  	if (file == NULL) {
 96  		printf("CBFS:  Could not find file %s\n",
 97  		       name);
 98  		return NULL;
 99  	}
100  
101  	if (ntohl(file->type) != type) {
102  		printf("CBFS:  File %s is of type %x instead of"
103  		       "type %x\n", name, file->type, type);
104  
105  		return NULL;
106  	}
107  	if (len != NULL) *len = file->len;
108  
109  	return (void *) CBFS_SUBHEADER(file);
110  }
111  
112  void open_cbfs(const char *filename)
113  {
114  	struct stat cbfs_stat;
115  	int cbfs_fd;
116  
117  	cbfs_fd = open(filename, O_RDWR);
118  	if (cbfs_fd == -1) {
119  		printf("Couldn't open '%s'\n", filename);
120  		exit(-1);
121  	}
122  	if (fstat(cbfs_fd, &cbfs_stat) == -1) {
123  		printf("Couldn't stat '%s'\n", filename);
124  		exit(-1);
125  	}
126  	cbfs_mapped = mmap(NULL, cbfs_stat.st_size, PROT_READ | PROT_WRITE,
127  			MAP_SHARED, cbfs_fd, 0);
128  	close(cbfs_fd);
129  	if (cbfs_mapped == MAP_FAILED) {
130  		printf("Couldn't map '%s'\n", filename);
131  		exit(-1);
132  	}
133  	cbfs_offset = cbfs_mapped-(0xffffffff-cbfs_stat.st_size+1);
134  }