1  #include "initrd.h"
 2  #include "memory.h"
 3  #include "string.h"
 4  #include "kernel.h"
 5  
 6  struct initrd_header* initrd_header;
 7  struct initrd_file_header* file_headers;
 8  struct fs_node* initrd_root;
 9  struct fs_node* initrd_dev;
10  struct fs_node* root_nodes;
11  uint32_t nroot_nodes;
12  
13  static struct dirent dirent;
14  
15  static uint32_t initrd_read(struct fs_node* node, uint32_t offset, uint32_t size, uint8_t* buffer) {
16      struct initrd_file_header header = file_headers[node->inode];
17      if (offset > header.length) {
18          return 0;
19      }
20      if (offset + size > header.length) {
21          size = header.length - offset;
22      }
23      memcpy(buffer, (uint8_t*)(header.offset + offset), size);
24      return size;
25  }
26  
27  static struct dirent* initrd_readdir(struct fs_node* node, uint32_t index) {
28      (void)node;
29      if (index >= nroot_nodes) {
30          return 0;
31      }
32      
33      strcpy(dirent.name, root_nodes[index].name);
34      dirent.name[strlen(root_nodes[index].name)] = 0;
35      dirent.ino = root_nodes[index].inode;
36      return &dirent;
37  }
38  
39  static struct fs_node* initrd_finddir(struct fs_node* node, char* name) {
40      (void)node;
41      for (uint32_t i = 0; i < nroot_nodes; i++) {
42          if (!strcmp(name, root_nodes[i].name)) {
43              return &root_nodes[i];
44          }
45      }
46      return 0;
47  }
48  
49  struct fs_node* initrd_init(uint32_t location) {
50      // Initialize the main and file header pointers
51      initrd_header = (struct initrd_header*)location;
52      file_headers = (struct initrd_file_header*)(location + sizeof(struct initrd_header));
53      
54      // Initialize the root directory
55      initrd_root = (struct fs_node*)kmalloc(sizeof(struct fs_node));
56      strcpy(initrd_root->name, "initrd");
57      initrd_root->mask = initrd_root->uid = initrd_root->gid = initrd_root->inode = initrd_root->length = 0;
58      initrd_root->flags = FS_DIRECTORY;
59      initrd_root->read = 0;
60      initrd_root->write = 0;
61      initrd_root->open = 0;
62      initrd_root->close = 0;
63      initrd_root->readdir = &initrd_readdir;
64      initrd_root->finddir = &initrd_finddir;
65      initrd_root->ptr = 0;
66      initrd_root->impl = 0;
67      
68      // Initialize file nodes
69      nroot_nodes = initrd_header->nfiles;
70      root_nodes = (struct fs_node*)kmalloc(sizeof(struct fs_node) * nroot_nodes);
71      
72      for (uint32_t i = 0; i < nroot_nodes; i++) {
73          // Edit the file's header, rn it holds the file offset relative to the start of the ramdisk
74          // We want it relative to the start of memory
75          file_headers[i].offset += location;
76          
77          // Create a new file node
78          strcpy(root_nodes[i].name, file_headers[i].name);
79          root_nodes[i].mask = root_nodes[i].uid = root_nodes[i].gid = 0;
80          root_nodes[i].length = file_headers[i].length;
81          root_nodes[i].inode = i;
82          root_nodes[i].flags = FS_FILE;
83          root_nodes[i].read = &initrd_read;
84          root_nodes[i].write = 0;
85          root_nodes[i].open = 0;
86          root_nodes[i].close = 0;
87          root_nodes[i].readdir = 0;
88          root_nodes[i].finddir = 0;
89          root_nodes[i].impl = 0;
90      }
91      
92      terminal_writestring("Initrd loaded with ");
93      char buf[12];
94      itoa(nroot_nodes, buf, 10);
95      terminal_writestring(buf);
96      terminal_writestring(" files\n");
97      
98      return initrd_root;
99  }