initial features.in/dos

This was tackled before but it took raorn@'s hint regarding
sys-freedos-linux (ms-sys has no bootsectors compatible with
freedos currently) and gns@' quick rush at make-freedos-floppy
script to wrap things up.

Should be further developed to become actually useful though.

distro.mk

@@ -36,6 +36,7 @@ distro/syslinux: distro/.init distro/.branding sub/stage1 \
 
 distro/live: distro/.base use/live use/syslinux/ui-menu
 distro/rescue: distro/.base use/rescue use/syslinux/ui-menu
+distro/dos: sub/stage1 use/dos use/syslinux/ui-menu
 
 # something actually useful (as a network-only installer)
 # NB: doesn't carry stage3 thus cannot use/bootloader

features.in/dos/README

@@ -0,0 +1,6 @@
+Фича добавляет создание FreeDOS "live floppy" в stage1.
+
+Текущее состояние -- загружается минимальная система.
+Для практического применения (в первую очередь это
+перешивка firmware) требуется сделать подключение
+CD и/или USB Flash с тем, чтобы класть туда прошивки.

features.in/dos/config.mk

@@ -0,0 +1,5 @@
+use/dos: use/syslinux
+	@$(call add,FEATURES,dos)
+	@$(call add,SYSLINUX_CFG,dos)
+	@$(call add,SYSLINUX_FILES,/usr/lib/syslinux/memdisk)
+	@$(call add,STAGE1_PACKAGES,make-freedos-floppy glibc-gconv-modules)

features.in/dos/stage1/scripts.d/50-make-dos-floppy

@@ -0,0 +1,6 @@
+#!/bin/sh -x
+# create a barebone bootable freedos floppy
+# TODO: some sub-framework to populate it as well
+
+mkdir -p "$WORKDIR/syslinux"
+make-freedos-floppy "$WORKDIR/syslinux/freedos.img"

features.in/syslinux/cfg.in/85dos.cfg

@@ -0,0 +1,4 @@
+label freedos
+  menu label Live ^FreeDOS
+  kernel memdisk
+  append initrd=freedos.img