1 ;; -----------------------------------------------------------------------
3 ;; Copyright 1994-2007 H. Peter Anvin - All Rights Reserved
5 ;; This program is free software; you can redistribute it and/or modify
6 ;; it under the terms of the GNU General Public License as published by
7 ;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8 ;; Boston MA 02111-1307, USA; either version 2 of the License, or
9 ;; (at your option) any later version; incorporated herein by reference.
11 ;; -----------------------------------------------------------------------
14 ; This file should be entered with the config file open (for getc)
17 call parse_config ; Parse configuration file
21 ; Check whether or not we are supposed to display the boot prompt.
24 cmp word [ForcePrompt],0 ; Force prompt?
26 test byte [KbdFlags],5Bh ; Shift Alt Caps Scroll
27 jz auto_boot ; If neither, default boot
30 cmp word [NoEscape],0 ; If NOESCAPE, no prompt,
31 jne auto_boot ; always run default cmd
36 mov byte [FuncFlag],0 ; <Ctrl-F> not pressed
40 ; get the very first character -- we can either time
41 ; out, or receive a character press at this time. Some dorky BIOSes stuff
42 ; a return in the buffer on bootup, so wipe the keyboard buffer first.
44 clear_buffer: mov ah,11h ; Check for pending char
49 jmp short clear_buffer
51 ; For the first character, both KbdTimeout and
52 ; TotalTimeout apply; after that, only TotalTimeout.
55 mov eax,[TotalTimeout]
62 and dword [ThisKbdTo],0 ; For the next time...
67 got_ascii: cmp al,7Fh ; <DEL> == <BS>
72 cmp di,command_line ; Space must not be first
74 enter_char: test byte [FuncFlag],1
82 .not_ctrl_f: cmp di,max_cmd_len+command_line ; Check there's space
85 call writechr ; Echo to screen
87 not_ascii: mov byte [FuncFlag],0
90 cmp al,'F' & 1Fh ; <Ctrl-F>
93 cmp al,'N' & 1Fh ; <Ctrl-N>
96 cmp al,'U' & 1Fh ; <Ctrl-U>
97 je kill_command ; Kill input line
98 cmp al,'V' & 1Fh ; <Ctrl-V>
100 cmp al,'X' & 1Fh ; <Ctrl-X>
102 cmp al,08h ; Backspace
104 backspace: cmp di,command_line ; Make sure there is anything
105 je get_char ; to erase
106 dec di ; Unstore one character
107 mov si,wipe_char ; and erase it from the screen
121 mov byte [FuncFlag],1
124 ctrl_f_0: add al,10 ; <Ctrl-F>0 == F10
130 ; AL = 0 if we get here
136 show_help: ; AX = func key # (0 = F1, 9 = F10)
137 push di ; Save end-of-cmdline pointer
138 shl ax,FILENAME_MAX_LG2 ; Convert to pointer
141 cmp byte [di+NULLOFFSET],NULLFILE
142 je short fk_nofile ; Undefined F-key
144 jz short fk_nofile ; File not found
152 push di ; Command line write pointer
153 mov si,syslinux_banner
162 ; ... fall through ...
164 ; Write the boot prompt and command line again and
165 ; wait for input. Note that this expects the cursor
166 ; to already have been CRLF'd, and that the old value
167 ; of DI (the command line write pointer) is on the stack.
171 pop di ; Command line write pointer
173 mov byte [di],0 ; Null-terminate command line
175 call cwritestr ; Write command line so far
180 ; Show network info (in the form of the ipappend strings)
184 mov si,IPAppends ; See comboot.doc
198 ; Jump here to run the default command line
203 mov cx,(max_cmd_len+4) >> 2
205 jmp short load_kernel
208 ; Jump here when the command line is completed
212 cmp di,command_line ; Did we just hit return?
214 xor al,al ; Store a final null
217 load_kernel: ; Load the kernel now
219 ; First we need to mangle the kernel name the way DOS would...
227 ; Fast-forward to first option (we start over from the beginning, since
228 ; mangle_name doesn't necessarily return a consistent ending state.)
233 clin_is_wsp: and al,al
238 clin_opt_ptr: dec si ; Point to first nonblank
239 mov [CmdOptPtr],si ; Save ptr to first option
241 ; If "allowoptions 0", put a null character here in order to ignore any
242 ; user-specified options.
244 mov ax,[AllowOptions]
251 ; Now check if it is a "virtual kernel"
254 xor si,si ; Beginning of vk_seg
256 cmp si,[VKernelBytes]
266 ; SI updated on return
268 sub di,cx ; Return to beginning of buf
278 ; We *are* using a "virtual kernel"
282 push word real_mode_seg
285 mov si,VKernelBuf+vk_append
286 mov cx,[VKernelBuf+vk_appendlen]
288 mov [CmdLinePtr],di ; Where to add rest of cmd
292 mov si,VKernelBuf+vk_rname
293 mov cx,FILENAME_MAX ; We need ECX == CX later
297 mov al,[VKernelBuf+vk_ipappend]
300 xor bx,bx ; Try only one version
302 mov al, [VKernelBuf+vk_type]
305 %if IS_PXELINUX || IS_ISOLINUX
306 ; Is this a "localboot" pseudo-kernel?
308 cmp byte [VKernelBuf+vk_rname+4], 0
310 cmp byte [VKernelBuf+vk_rname], 0
312 jne get_kernel ; No, it's real, go get it
314 mov ax, [VKernelBuf+vk_rname+1]
323 ; Not a "virtual kernel" - check that's OK and construct the command line
325 cmp word [AllowImplicit],byte 0
341 mov [KernelType], cl ; CL == 0 here
344 ; Find the kernel on disk
346 get_kernel: mov byte [KernelName+FILENAME_MAX],0 ; Zero-terminate filename/extension
347 mov di,KernelName+4*IS_PXELINUX
349 mov cx,FILENAME_MAX-5 ; Need 4 chars + null
350 repne scasb ; Scan for final null
352 dec di ; Point to final null
353 .no_skip: mov [KernelExtPtr],di
355 .search_loop: push bx
356 mov di,KernelName ; Search on disk
360 mov eax,[bx] ; Try a different extension
361 mov si,[KernelExtPtr]
365 cmp bx,exten_table_end
366 jna .search_loop ; allow == case (final case)
367 ; Fall into bad_kernel
369 ; bad_kernel: Kernel image not found
370 ; bad_implicit: The user entered a nonvirtual kernel name, with "implicit 0"
381 call unmangle_name ; Get human form
382 mov si,err_notfound ; Complain about missing kernel
387 jmp abort_load ; Ask user for clue
390 ; on_error: bad kernel, but we have onerror set; CX = OnerrorLen
401 pop di ; <E> di == command_line
402 pop bx ; <D> bx == [OnerrorLen]
403 je bad_kernel.really ; Onerror matches command_line already
404 neg bx ; bx == -[OnerrorLen]
405 lea cx,[max_cmd_len+bx]
406 ; CX == max_cmd_len-[OnerrorLen]
407 mov di,command_line+max_cmd_len-1
408 mov byte [di+1],0 ; Enforce null-termination
411 rep movsb ; Make space in command_line
413 pop cx ; <C> cx == [OnerrorLen]
414 pop di ; <B> di == command_line
415 pop si ; <A> si == Onerror
420 ; kernel_corrupt: Called if the kernel file does not seem healthy
422 kernel_corrupt: mov si,err_notkernel
426 ; Get a key, observing ThisKbdTO and ThisTotalTO -- those are timeouts
427 ; which can be adjusted by the caller based on the corresponding
428 ; master variables; on return they're updated.
430 ; This cheats. If we say "no timeout" we actually get a timeout of
438 push word [BIOS_timer]
442 cmp ax,[BIOS_timer] ; Has the timer advanced?
446 dec dword [ThisKbdTo]
448 dec dword [ThisTotalTo]
453 pop cx ; Discard return address
455 mov si,Ontimeout ; Copy ontimeout command
457 mov cx,[OntimeoutLen] ; if we have one...
468 ; This is it! We have a name (and location on the disk)... let's load
469 ; that sucker!! First we have to decide what kind of file this is; base
470 ; that decision on the file extension. The following extensions are
471 ; recognized; case insensitive:
473 ; .com - COMBOOT image
474 ; .cbt - COMBOOT image
477 ; .0 - PXE bootstrap program (PXELINUX only)
479 ; .bss - Boot sector, but transfer over DOS superblock (SYSLINUX only)
480 ; .img - Floppy image (ISOLINUX only)
482 ; Anything else is assumed to be a Linux kernel.
491 ; Alternate entry point for which the return from
492 ; searchdir is stored in memory. This is used for
493 ; COMBOOT function INT 22h, AX=0016h.
496 mov dx,[Kernel_EAX+2]
504 mov [KernelCNameLen],di
509 mov di,KernelName+4*IS_PXELINUX
515 .one_step: mov ecx,[di-4] ; 4 bytes before end
520 ; At this point, DX:AX contains the size of the kernel, SI contains
521 ; the file handle/cluster pointer, and ECX contains the extension (if any.)
523 movzx di,byte [KernelType]
525 jmp [kerneltype_table+di]
528 or ecx,20202000h ; Force lower case (except dot)
551 ; Otherwise Linux kernel
556 mov si,KernelCName ; Save the config file name, for posterity
564 ; This is an image type we can't deal with
570 %if IS_SYSLINUX || IS_MDSLINUX
573 is_bss_sector equ is_bad_image
578 is_disk_image equ is_bad_image
582 err_badimage db 'Invalid image type for this media type!', CR, LF, 0
586 dw is_unknown_filetype ; VK_KERNEL
587 dw is_linux_kernel ; VK_LINUX
588 dw is_bootsector ; VK_BOOT
589 dw is_bss_sector ; VK_BSS
590 dw is_bootsector ; VK_PXE
591 dw is_disk_image ; VK_FDIMAGE
592 dw is_comboot_image ; VK_COMBOOT
593 dw is_com32_image ; VK_COM32
594 dw is_config_file ; VK_CONFIG
598 ThisKbdTo resd 1 ; Temporary holder for KbdTimeout
599 ThisTotalTo resd 1 ; Temporary holder for TotalTimeout
600 KernelExtPtr resw 1 ; During search, final null pointer
601 CmdOptPtr resw 1 ; Pointer to first option on cmd line
602 KbdFlags resb 1 ; Check for keyboard escapes
603 FuncFlag resb 1 ; Escape sequences received from keyboard
604 KernelType resb 1 ; Kernel type, from vkernel, if known