1 files changed, 103 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/core/fs/chdir.c b/contrib/syslinux-4.02/core/fs/chdir.c
new file mode 100644
index 0000000..9e8dfd2
--- /dev/null
+++ b/contrib/syslinux-4.02/core/fs/chdir.c
@@ -0,0 +1,103 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include "fs.h"
+#include "cache.h"
+
+/*
+ * Convert a relative pathname to an absolute pathname
+ * In the future this might also resolve symlinks...
+ */
+void pm_realpath(com32sys_t *regs)
+{
+    const char *src = MK_PTR(regs->ds, regs->esi.w[0]);
+    char       *dst = MK_PTR(regs->es, regs->edi.w[0]);
+
+    realpath(dst, src, FILENAME_MAX);
+}
+
+#define EMIT(x)		     		\
+do {		     			\
+    if (++n < bufsize)	 		\
+    	*q++ = (x);			\
+} while (0)
+
+static size_t join_paths(char *dst, size_t bufsize,
+			 const char *s1, const char *s2)
+{
+    const char *list[2];
+    int i;
+    char c;
+    const char *p;
+    char *q  = dst;
+    size_t n = 0;
+    bool slash = false;
+    
+    list[0] = s1;
+    list[1] = s2;
+
+    for (i = 0; i < 2; i++) {
+	p = list[i];
+
+	while ((c = *p++)) {
+	    if (c == '/') {
+		if (!slash)
+		    EMIT(c);
+		slash = true;
+	    } else {
+		EMIT(c);
+		slash = false;
+	    }
+	}
+    }
+
+    if (bufsize)
+	*q = '\0';
+
+    return n;
+}
+
+size_t realpath(char *dst, const char *src, size_t bufsize)
+{
+    if (this_fs->fs_ops->realpath) {
+	return this_fs->fs_ops->realpath(this_fs, dst, src, bufsize);
+    } else {
+	/* Filesystems with "common" pathname resolution */
+	return join_paths(dst, bufsize, 
+			  src[0] == '/' ? "" : this_fs->cwd_name,
+			  src);
+    }
+}
+
+int chdir(const char *src)
+{
+    int rv;
+    struct file *file;
+    char cwd_buf[CURRENTDIR_MAX];
+
+    if (this_fs->fs_ops->chdir)
+	return this_fs->fs_ops->chdir(this_fs, src);
+
+    /* Otherwise it is a "conventional filesystem" */
+    rv = searchdir(src);
+    if (rv < 0)
+	return rv;
+
+    file = handle_to_file(rv);
+    if (file->inode->mode != DT_DIR) {
+	_close_file(file);
+	return -1;
+    }
+
+    put_inode(this_fs->cwd);
+    this_fs->cwd = get_inode(file->inode);
+    _close_file(file);
+
+    /* Save the current working directory */
+    realpath(cwd_buf, src, CURRENTDIR_MAX);
+
+    /* Make sure the cwd_name ends in a slash, it's supposed to be a prefix */
+    join_paths(this_fs->cwd_name, CURRENTDIR_MAX, cwd_buf, "/");
+
+    return 0;
+}