limine: Make module paths better defined

PROTOCOL.md

@@ -502,6 +502,8 @@ struct limine_module_response {
 * `modules` - Pointer to an array of `module_count` pointers to
 `struct limine_module` structures.
 
+Note: The first module (module 0) is always the kernel file.
+
 ```c
 struct limine_module {
     void *base;
@@ -514,7 +516,7 @@ struct limine_module {
 
 * `base` - The address of the module.
 * `length` - The size of the module.
-* `path` - The bootloader-specific path of the module.
+* `path` - The path of the module within the volume, with a leading slash.
 * `cmdline` - A command line associated with the module.
 * `file_location` - A pointer to the file location structure for the module.
 

common/fs/file.h

@@ -9,12 +9,15 @@
 #  include <efi.h>
 #endif
 
+#define PATH_MAX 4096
+
 bool fs_get_guid(struct guid *guid, struct volume *part);
 
 struct file_handle {
     bool       is_memfile;
     bool       readall;
     struct volume *vol;
+    char       path[PATH_MAX];
     void      *fd;
     void     (*read)(void *fd, void *buf, uint64_t loc, uint64_t count);
     void     (*close)(void *fd);

common/fs/file.s2.c

@@ -32,6 +32,14 @@ struct file_handle *fopen(struct volume *part, const char *filename) {
 
     ret->vol = part;
 
+    if (strlen(filename) + 2 > PATH_MAX) {
+        panic(true, "fopen: Path too long");
+    }
+
+    ret->path[0] = '/';
+
+    strcpy(ret->path + 1, filename);
+
 #if bios == 1
     if (part->pxe) {
         if (!tftp_open(ret, 0, 69, filename)) {

common/protos/limine.c

@@ -120,6 +120,9 @@ bool limine_load(char *config, char *cmdline) {
     if ((kernel_file = uri_open(kernel_path)) == NULL)
         panic(true, "limine: Failed to open kernel with path `%s`. Is the path correct?", kernel_path);
 
+    char *kpath = ext_mem_alloc(strlen(kernel_file->path) + 1);
+    strcpy(kpath, kernel_file->path);
+
     uint8_t *kernel = freadall(kernel_file, MEMMAP_BOOTLOADER_RECLAIMABLE);
 
     size_t kernel_file_size = kernel_file->size;
@@ -369,7 +372,7 @@ FEAT_START
 
     modules[0].base = reported_addr(kernel);
     modules[0].length = kernel_file_size;
-    modules[0].path = reported_addr(kernel_path);
+    modules[0].path = reported_addr(kpath);
     modules[0].cmdline = reported_addr(cmdline);
 
     modules[0].file_location = reported_addr(kl);
@@ -396,7 +399,11 @@ FEAT_START
 
         m->base = reported_addr(freadall(f, MEMMAP_KERNEL_AND_MODULES));
         m->length = f->size;
-        m->path = reported_addr(module_path);
+
+        char *mpath = ext_mem_alloc(strlen(f->path) + 1);
+        strcpy(mpath, f->path);
+        m->path = reported_addr(mpath);
+
         m->cmdline = reported_addr(module_cmdline);
 
         struct limine_file_location *l = ext_mem_alloc(sizeof(struct limine_file_location));