chore: work on VFS (wip)

Refs: #24

kernel/Makefile

@@ -17,7 +17,11 @@ SRCS	= kernel.asm \
 			dev/at/pit.inc \
 			dev/at/cga.inc \
 			dev/at/kbd.inc \
-			dev/at/floppy.inc
+			dev/at/floppy.inc \
+			fs/fat.inc \
+			fs/stpdfs.inc \
+			fs/xv6fs.inc \
+			vfs.inc
 
 .PHONY: all
 all: $(KERNEL)

kernel/dev/at/cmos.inc

@@ -1,13 +1,58 @@
 	;; File: cmos.inc 
 	;;
-	;; > +--------------------------------
+	;; > +------+-------------------------+
-	;; > | 0x00 | RTC seconds
+	;; > | 0x00 | RTC seconds             |
-	;; > +---------------
+	;; > +------+-------------------------+
-	;; > | 0x01 | RTC seconds alarm
+	;; > | 0x01 | RTC seconds alarm       |
-	;; > +--------------------
+	;; > +------+-------------------------+
-	;; > | 0x02 | RTC minutes
+	;; > | 0x02 | RTC minutes             |
-	;; > +------------------------
+	;; > +------+-------------------------+
-
+	;; > | 0x03 | RTC minutes alarm       |
+	;; > +------+-------------------------+
+	;; > | 0x04 | RTC hours               |
+	;; > +------+-------------------------+
+	;; > | 0x05 | RTC hours alarm         |
+	;; > +------+-------------------------+
+	;; > | 0x06 | RTC day of week         |
+	;; > +------+-------------------------+
+	;; > | 0x07 | RTC date day            |
+	;; > +------+-------------------------+
+	;; > | 0x08 | RTC date month          |
+	;; > +------+-------------------------+
+	;; > | 0x09 | RTC date year           |
+	;; > +------+-------------------------+
+	;; > | 0x0A | Status register A       |
+	;; > +------+-------------------------+
+	;; > | 0x0B | Status register B       |
+	;; > +------+-------------------------+
+	;; > | 0x0C | Status register C       |
+	;; > +------+-------------------------+
+	;; > | 0x0D | Status register D       |
+	;; > +------+-------------------------+
+	;; > | 0x0E | Diagnostic Status       |
+	;; > +------+-------------------------+
+	;; > | 0x0F | CMOS Shutdown Status    |
+	;; > +------+-------------------------+
+	;; > | 0x10 | Floppy Disk Drive Type  |
+	;; > +------+-------------------------+
+	;; > | 0x11 | System Conf Settings    |
+	;; > +------+-------------------------+
+	;; > | 0x12 | Hard Disk Type          |
+	;; > +------+-------------------------+
+	;; > | 0x13 | Typematic Parameters    |
+	;; > +------+-------------------------+
+	;; > | 0x14 | Installed Equipment     |
+	;; > +------+-------------------------+
+	;; > | 0x15 | Base Memory LO          |
+	;; > +------+-------------------------+
+	;; > | 0x16 | Base Memory HI          |
+	;; > +------+-------------------------+
+	;; > | 0x17 | Extended Memory LO      |
+	;; > +------+-------------------------+
+	;; > | 0x18 | Extended Memory HI      |
+	;; > +------+-------------------------+
+	;; > | 0x19 | Hard Disk Extended Type |
+	;; > +------+-------------------------+
 
 CMOS_COMMAND = 0x70
 CMOS_DATA    = 0x71

kernel/dev/console.inc

@@ -18,4 +18,7 @@ console_read:
 	call lock_release
 	ret
 
+console_init:
+	ret
+
 uConsoleLock dd 0

kernel/dev/dev.inc

@@ -6,3 +6,5 @@ struc Device {
 	.probe dd ?
 }
 
+dev_init:
+	ret

kernel/fs/fat.inc

@@ -1,9 +1,73 @@
 	;; File: fat.inc
+	;;
+	;; Usefull links:
+	;; - <Spec at https://academy.cba.mit.edu/classes/networking_communications/SD/FAT.pdf>
 
 FAT_SECTOR_SIZE = 512
 FAT_MDIR_SIZE   = 32
 
-struc FatBootSector {
+struc FATFS_BootSectorBase {
-	.jump   db 3 dup(?)
+	.jump         db 3 dup(?)
-	.banner db 8 dup(?)
+	.oemName      db 8 dup(?)
+	.byts_per_sec dw ?
+	.sec_per_clus db ?
+	.rsvd_sec_cnt dw ?
+	.num_fats     db ?
+	.root_ent_cnt dw ?
+	.tot_sec16    dw ?
+	.media        db ?
+	.fat_sz16     dw ?
+	.sec_per_trk  dw ?
+	.num_heads    dw ?
+	.hidd_sec     dd ?
+	.tot_sec32    dd ?
 }
+
+struc FATFS_BootSector16 {
+	.base FATFS_BootSectorBase
+
+	;; Extended BPB Structure
+	.drv_num      db ?
+	.reserved1    db 0
+	.boot_sig     db ?
+	.volume_id    dd ?
+	.volume_label db 11 dup(?)
+	.filsys_type  db 8 dup(?)
+	.code         db 448 dup(?)
+	.signature    dw ?
+}
+
+struc FATFS_BootSector32 {
+	.base FATFS_BootSectorBase
+
+	.fat_sz32     dd ?
+	.ext_flags    dw ?
+	.fs_ver       dw ?
+	.root_clus    dd ?
+	.fs_info      dw ?
+	.bk_boot_sec  dw ?
+	.reserved0    db 12 dup(?)
+	.drv_num      db ?
+	.reserved1    db ?
+	.boot_sig     db ?
+	.volume_id    dd ?
+	.volume_label db 11 dup(?)
+	.filsys_type  db 8 dup(?)
+	.code         db 420 dup(?)
+	.signature    dw ?
+}
+
+szVfsFatName db 'FATFS', 0
+
+vfs_fatfs:
+	dd szVfsFatName
+	dd 0
+	dd vops_fatfs
+
+vops_fatfs:
+	dd 0
+
+fatfs_init:
+	mov eax, vfs_fatfs
+	call vfs_register
+	ret

kernel/fs/stpdfs.inc

@@ -1,5 +1,51 @@
 	;; File: stpdfs.inc
 
 STPDFS_SB_MAGIC = 0x44505453
-STPDFS_SB_REV = 1
+STPDFS_SB_REV   = 1
+STPDFS_BSIZE    = 512
+STPDFS_ROOTINO  = 1
+STPDFS_NDIRECT  = 7
 
+STPDFS_CLEANLY_UNMOUNTED = 0
+STPDFS_ERROR             = 1
+STPDFS_DIRTY             = 1
+
+struc StpdFS_Sb {
+	.magic dd ?
+	.isize dd ?
+	.fsize dd ?
+	.free  dd 100 dup(?)
+	.nfree db ?
+	.rev   db ?
+	.state dw ?
+	.time  dq ?
+}
+DEFN StpdFS_Sb
+
+struc StpdFS_Inode {
+	.mode    dw ?
+	.nlink   dw ?
+	.uid     dw ?
+	.gid     dw ?
+	.flags   dw ?
+	.size    dd ?
+	.zones   dd (STPDFS_NDIRECT + 3) dup(?)
+	.actime  dq ?
+	.modtime dq ?
+}
+DEFN StpdFS_Inode
+
+szVfsStpdFSName db 'StupidFS', 0
+
+vops_stpdfs:
+	dd 0
+
+vfs_stpdfs:
+	dd szVfsStpdFSName
+	dd 0
+	dd vops_stpdfs
+
+stpdfs_init:
+	mov eax, vfs_stpdfs
+	call vfs_register
+	ret

kernel/fs/xv6fs.inc

@@ -0,0 +1,57 @@
+	;; File: xv6fs.inc
+	;;
+	;; Usefull links:
+	;; - <https://github.com/mit-pdos/xv6-riscv/blob/riscv/kernel/fs.h>
+	;; - <xv6 book at https://pdos.csail.mit.edu/6.1810/2023/xv6/book-riscv-rev3.pdf>
+
+XV6FS_BSIZE     = 1024
+XV6FS_ROOTINO   = 1
+XV6FS_MAGIC     = 0x10203040
+XV6FS_NDIRECT   = 12
+XV6FS_NINDIRECT = (XV6FS_BSIZE / 4)
+XV6FS_MAXFILE   = (XV6FS_NDIRECT + XV6FS_NINDIRECT)
+XV6FS_IPB       = (XV6FS_BSIZE / 64)
+XV6FS_DIRSIZE   = 14 
+
+struc Xv6FS_Sb {
+	.magic      dd ?
+	.size       dd ?
+	.nblock     dd ?
+	.ninodes    dd ?
+	.nlog       dd ?
+	.nlogstart  dd ?
+	.inodestart dd ?
+	.bmapstart  dd ?
+}
+DEFN Xv6FS_Sb
+
+struc Xv6FS_Inode {
+	.type  dw ?
+	.major dw ?
+	.minor dw ?
+	.nlink dw ?
+	.size  dd ?
+	.addrs dd (XV6FS_NDIRECT + 1) dup(?)
+}
+DEFN Xv6FS_Inode
+
+struc Xv6FS_Dirent {
+	.inum dw ?
+	.name db XV6FS_DIRSIZE dup(?)
+}
+
+szVfsXv6FSName db 'xv6FS', 0
+
+vops_xv6fs:
+	dd 0
+
+vfs_xv6fs:
+	dd szVfsXv6FSName
+	dd 0
+	dd vops_xv6fs
+
+xv6fs_init:
+	mov eax, vfs_xv6fs
+	call vfs_register
+	ret
+

kernel/kernel.asm

@@ -2,6 +2,7 @@
 	format binary
 
 	include 'const.inc'
+	include 'sys/macro.inc'
 	include 'sys/bootinfo.inc'
 	include 'sys/cpu.inc'
 
@@ -64,6 +65,8 @@ kmain:
 
 	call pit_init
 
+	call vfs_init
+
 	mov eax, SYSCALL_EXIT
 	int 0x42
 
@@ -81,6 +84,11 @@ kmain:
 	call klog
 	jmp .halt
 
+	include 'dev/at/cmos.inc'
+	include 'dev/at/pit.inc'
+	include 'dev/at/kbd.inc'
+	include 'dev/at/cga.inc'
+	include 'dev/at/floppy.inc'
 	include 'klog.inc'
 	include 'dev/console.inc'
 	include 'mm/mm.inc'
@@ -90,10 +98,10 @@ kmain:
 	include 'isr.inc'
 	include 'idt.inc'
 	include 'pic.inc'
-	include 'dev/at/pit.inc'
+	include 'vfs.inc'
-	include 'dev/at/kbd.inc'
+	include 'fs/fat.inc'
-	include 'dev/at/cga.inc'
+	include 'fs/stpdfs.inc'
-	include 'dev/at/floppy.inc'
+	include 'fs/xv6fs.inc'
 
 
 szMsgKernelAlive db "Kernel (", VERSION_FULL , ") is alive", 0

kernel/sys/macro.inc

@@ -0,0 +1,6 @@
+macro DEFN x {
+virtual at 0
+  x x
+  sizeof.#x:
+end virtual
+}

kernel/vfs.inc

@@ -5,6 +5,13 @@
 	;;
 
 struc VFS {
+	.name   dd ?
+	.next   dd ?
+	.op     dd ?
+}
+DEFN VFS
+
+struc Mount {
 	.next   dd ?
 	.op     dd ?
 	.vnodes dd ?
@@ -23,6 +30,7 @@ struc VFSOps {
 	.vget   dd ?
 }
 
+	;; 
 VNODE_TYPE_NON  = 0x0
 VNODE_TYPE_REG  = 0x1
 VNODE_TYPE_DIR  = 0x2
@@ -32,6 +40,7 @@ VNODE_TYPE_LNK  = 0x5
 VNODE_TYPE_SOCK = 0x6
 VNODE_TYPE_BAD  = 0x7
 
+	;; Struc: VNode
 struc VNode {
 	.flag     dw ?
 	.refcount dw ?
@@ -72,8 +81,29 @@ struc VNodeOps {
 	.brelse   dd ?
 }
 
-vfs_init:
+	;; Function: vfs_register
+	;;
+	;; In:
+	;;    EAX - Pointer to VFS struct
+	;;
+vfs_register:
+	mov edx, [pVFS]
+	mov [eax + VFS.next], edx
+	mov [pVFS], eax
+
+	mov eax, [eax + VFS.name]
+	push eax
+	mov esi, szMsgVFSRegister
+	call klog
 	ret
 
+vfs_init:
+	call fatfs_init
+	call stpdfs_init
+	call xv6fs_init
+	ret
 
+pVFS    dd 0
 pRootFS dd 0
+
+szMsgVFSRegister db 'VFS: register %s', 0