20060303

1 files changed, 94 insertions, 0 deletions

diff --git a/os/boot/pc/fs.c b/os/boot/pc/fs.c
new file mode 100644
index 00000000..24b33c09
--- /dev/null
+++ b/os/boot/pc/fs.c
@@ -0,0 +1,94 @@
+#include	"u.h"
+#include	"lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+
+#include	"fs.h"
+
+/*
+ *  grab next element from a path, return the pointer to unprocessed portion of
+ *  path.
+ */
+char *
+nextelem(char *path, char *elem)
+{
+	int i;
+
+	while(*path == '/')
+		path++;
+	if(*path==0 || *path==' ')
+		return 0;
+	for(i=0; *path!='\0' && *path!='/' && *path!=' '; i++){
+		if(i==NAMELEN){
+			print("name component too long\n");
+			return 0;
+		}
+		*elem++ = *path++;
+	}
+	*elem = '\0';
+	return path;
+}
+
+int
+fswalk(Fs *fs, char *path, File *f)
+{
+	char element[NAMELEN];
+
+	*f = fs->root;
+	if(BADPTR(fs->walk))
+		panic("fswalk bad pointer fs->walk");
+
+	f->path = path;
+	while(path = nextelem(path, element)){
+		switch(fs->walk(f, element)){
+		case -1:
+			return -1;
+		case 0:
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/*
+ *  boot
+ */
+int
+fsboot(Fs *fs, char *path, Boot *b)
+{
+	File file;
+	long n;
+	static char buf[8192];
+
+	switch(fswalk(fs, path, &file)){
+	case -1:
+		print("error walking to %s\n", path);
+		return -1;
+	case 0:
+		print("%s not found\n", path);
+		return -1;
+	case 1:
+		print("found %s\n", path);
+		break;
+	}
+
+	while((n = fsread(&file, buf, sizeof buf)) > 0) {
+		if(bootpass(b, buf, n) != MORE)
+			break;
+	}
+
+	bootpass(b, nil, 0);	/* tries boot */
+	return -1;
+}
+
+int
+fsread(File *file, void *a, long n)
+{
+	if(BADPTR(file->fs))
+		panic("bad pointer file->fs in fsread");
+	if(BADPTR(file->fs->read))
+		panic("bad pointer file->fs->read in fsread");
+	return file->fs->read(file, a, n);
+}