feat(scribe): Implement Scribe Editor Save & Stabilize VirtIO-Block

- hal/virtio_block: Implemented global bounce buffers and Used Ring Polling for stable, synchronous I/O.
- core/fs/sfs: Implemented sfs_write_file to handle SFS file creation and data writing.
- core/ion: Added CMD_FS_WRITE syscall definition.
- core/kernel: Added CMD_FS_WRITE syscall handler and fs/sfs integration.
- npl/nipbox: Added nexus_file_write wrapper and updated Scribe (ed) to use it for saving files.

src/editor.nim

@@ -0,0 +1,63 @@
+# Markus Maiwald (Architect) | Voxis Forge (AI)
+# Scribe: The Sovereign Editor
+# A modal line editor for the Sovereign Userland.
+
+import std
+
+var scribe_buffer: seq[string] = @[]
+var scribe_filename: string = ""
+
+proc scribe_save() =
+  # 1. Create content string
+  var content = ""
+  for line in scribe_buffer:
+    content.add(line)
+    content.add('\n')
+
+  # 2. Write to Disk (Using SFS)
+  print("[Scribe] Saving '" & scribe_filename & "'...")
+  nexus_file_write(scribe_filename, content)
+
+proc start_editor*(filename: string) =
+  scribe_filename = filename
+  scribe_buffer = @[]
+
+  print("Scribe v1.0. Editing: " & filename)
+  if filename == "matrix.conf":
+    # Try autoload?
+    print("(New File)")
+
+  while true:
+    var line = ""
+    print_raw(": ")
+    if not my_readline(line): break
+
+    if line == ".":
+      # Command Mode
+      while true:
+        var cmd = ""
+        print_raw("(cmd) ")
+        if not my_readline(cmd): break
+
+        if cmd == "w":
+          scribe_save()
+          print("Saved.")
+          break # Back to prompt or stay? Ed stays in command mode?
+          # Ed uses '.' to toggle? No, '.' ends insert.
+          # Scribe: '.' enters Command Menu single-shot.
+        elif cmd == "p":
+          var i = 1
+          for l in scribe_buffer:
+            print_int(i); print_raw(" "); print(l)
+            i += 1
+          break
+        elif cmd == "q":
+          return
+        elif cmd == "i":
+          print("(Insert Mode)")
+          break
+        else:
+          print("Unknown command. w=save, p=print, q=quit, i=insert")
+    else:
+      # Append
+      scribe_buffer.add(line)

src/nipbox.nim

@@ -1,33 +1,16 @@
 # src/npl/nipbox/nipbox.nim
 
-# --- 1. RAW IMPORTS (The Physics) ---
+import strutils
-# We talk directly to libc_shim.zig
+import std
+import editor
 
-type
+# Constants
-  cint = int32
+const
-  csize_t = uint
+  CMD_SYS_EXIT = 1
-  cptr = pointer
+  CMD_GPU_MATRIX = 0x100
-
+  CMD_GPU_STATUS = 0x102
-# Standard POSIX-ish
+  CMD_GET_GPU_STATUS = 0x102
-proc write(fd: cint, buf: cptr, count: csize_t): csize_t {.importc, cdecl.}
+  CMD_SYS_EXEC = 0x400
-proc read(fd: cint, buf: cptr, count: csize_t): csize_t {.importc, cdecl.}
-proc open(pathname: cstring, flags: cint): cint {.importc, cdecl.}
-proc close(fd: cint): cint {.importc, cdecl.}
-proc exit(status: cint) {.importc, cdecl.}
-proc list_files(buf: pointer, len: uint64): int64 {.importc, cdecl.}
-
-# Our Custom Syscalls (Defined in libc_shim)
-proc nexus_syscall(cmd: cint, arg: uint64): cint {.importc, cdecl.}
-proc nexus_yield() {.importc, cdecl.}
-proc nexus_net_tx(buf: cptr, len: uint64) {.importc, cdecl.}
-proc nexus_net_rx(buf: cptr, max_len: uint64): uint64 {.importc, cdecl.}
-proc nexus_blk_read(sector: uint64, buf: cptr, len: uint64) {.importc, cdecl.}
-proc nexus_blk_write(sector: uint64, buf: cptr, len: uint64) {.importc, cdecl.}
-
-const CMD_GPU_MATRIX = 0x100
-const CMD_GPU_STATUS = 0x102
-const CMD_GET_GPU_STATUS = 0x102
-const CMD_SYS_EXEC = 0x400
 
 # --- SOVEREIGN NETWORKING TYPES ---
 type
@@ -348,6 +331,7 @@ proc main() =
     elif cmd == "exec": do_exec(arg)
     elif cmd == "dd": do_dd(arg)
     elif cmd == "mkfs": do_mkfs()
+    elif cmd == "ed": start_editor(arg)
     elif cmd == "help": do_help()
     else: print("Unknown command: " & cmd)
 

src/std.nim

@@ -0,0 +1,101 @@
+# Standard C Types
+# cint, csize_t are in system/ctypes (implicitly available?)
+# If not, we fix it by aliasing system ones or just using int/uint.
+# Let's try relying on system.
+type
+  cptr* = pointer
+
+# Standard POSIX-ish Wrappers (from libc_shim)
+proc write*(fd: cint, buf: cptr, count: csize_t): csize_t {.importc, cdecl.}
+proc read*(fd: cint, buf: cptr, count: csize_t): csize_t {.importc, cdecl.}
+proc open*(pathname: cstring, flags: cint): cint {.importc, cdecl.}
+proc close*(fd: cint): cint {.importc, cdecl.}
+proc exit*(status: cint) {.importc, cdecl.}
+proc list_files*(buf: pointer, len: uint64): int64 {.importc, cdecl.}
+
+# Our Custom Syscalls (Defined in libc_shim)
+proc nexus_syscall*(cmd: cint, arg: uint64): cint {.importc, cdecl.}
+proc nexus_yield*() {.importc, cdecl.}
+proc nexus_net_tx*(buf: cptr, len: uint64) {.importc, cdecl.}
+proc nexus_net_rx*(buf: cptr, max_len: uint64): uint64 {.importc, cdecl.}
+proc nexus_blk_read*(sector: uint64, buf: cptr, len: uint64) {.importc, cdecl.}
+proc nexus_blk_write*(sector: uint64, buf: cptr, len: uint64) {.importc, cdecl.}
+
+type
+  FileArgs* = object
+    name*: uint64
+    data*: uint64
+    len*: uint64
+
+const CMD_FS_WRITE = 0x203
+
+proc nexus_file_write*(name: string, data: string) =
+  var args: FileArgs
+  args.name = cast[uint64](cstring(name))
+  args.data = cast[uint64](cstring(data))
+  args.len = uint64(data.len)
+  discard nexus_syscall(cint(CMD_FS_WRITE), cast[uint64](addr args))
+
+# Helper: Print to Stdout (FD 1)
+proc print*(s: string) =
+  if s.len > 0:
+    discard write(1, unsafeAddr s[0], csize_t(s.len))
+  var nl = "\n"
+  discard write(1, unsafeAddr nl[0], 1)
+
+proc print_raw*(s: string) =
+  if s.len > 0:
+    discard write(1, unsafeAddr s[0], csize_t(s.len))
+
+proc print_int*(n: int) =
+  var s = ""
+  var v = n
+  if v == 0: s = "0"
+  else:
+    while v > 0:
+      s.add(char((v mod 10) + 48))
+      v = v div 10
+  # Reverse
+  var r = ""
+  var i = s.len - 1
+  while i >= 0:
+    r.add(s[i])
+    i -= 1
+  print_raw(r)
+
+var read_buffer: array[512, char]
+var read_pos = 0
+var read_len = 0
+
+# Need to pull poll_network from somewhere?
+# Or just define a dummy or export proper one?
+# poll_network logic causes circular dep if it's in main.
+# Let's make my_readline simpler for now, or move poll_network here?
+# poll_network uses `nexus_net_rx`.
+# Let's move poll_network to std?
+# It depends on `nipbox` logic (checksums?).
+# Let's just do blocking read in my_readline for now without network polling for Phase 12 MVP.
+# Actually `libc_shim` `read(0)` is synchronous (busy wait on ring).
+# So poll_network inside loop was useful.
+# We will skip net poll in readline for this refactor to avoid complexity.
+
+proc my_readline*(out_str: var string): bool =
+  out_str = ""
+  while true:
+    var c: char
+    let n = read(0, addr c, 1)
+    if n <= 0: return false # EOF or Error
+
+    if c == '\n' or c == '\r':
+      print_raw("\n")
+      return true
+    elif c == '\b' or c == char(127): # Backspace
+      if out_str.len > 0:
+        # Visual backspace
+        var bs = "\b \b"
+        discard write(1, addr bs[0], 3)
+        out_str.setLen(out_str.len - 1)
+    else:
+      out_str.add(c)
+      discard write(1, addr c, 1) # Echo
+