Linux-0.11 (December 8, 1991)

This was created from a re-packaged 0.11 tree.

Linux-0.11 has a few rather major improvements, but perhaps most
notably, is the first kernel where some other people start making
real contributions.

 - I fixed the buffer cache code, making it a lot more stable

 - demand-loading from disk. My comment proudly states:

        Once more I can proudly say that linux stood up to being changed: it
        was less than 2 hours work to get demand-loading completely implemented.

   This is a major milestone, since it makes the kernel much more
   powerful than Minix was at the time.  I also share clean pages.

 - we still don't have an /sbin/init, but we now load /etc/rc at bootup,
   and the kernel will loop, spawning shells forever. That makes it easier
   to test things.

 - scaffolding for math emulation introduced.

 - Ted Ts'o shows up as a coder. Ted implements:
        o "#!" escape handling for executables
        o fixes for some file permission handling
        o "sticky" directory bit
        o first "malloc()/free()" implementation.
          (this one is horrible: the free needs the size for good
           performance, which will result in years of "free_s()" pains)
        o adds BSD-style setreuid/gid() handling
        o allows us to specify root device at image build time
        o cleanups of some of the uglier direct %fs-register accesses

 - Galen Hunt shows up as a coder: he's added code to handle different
   video card detection (whereas my original one just handled VGA, we
   now handle CGA, MGA, EGA and VGA)

 - The console can beep now: John T Kohl (who also does the tty KILL
   char handling)

 - we also now have German (Wolfgang Thiel) and French (Marc Corsini)
   keyboard maps.  World Domination!

Btw, if you wonder what the "Urgel" comments are - I was still fairly
Swedish-speaking, and "Urgel" is what I would these days write as "Ugh".

It's a sign of trouble or ugly code.  The floppy driver in particular is
clearly not something I'm very proud of ;).

Makefile

@@ -1,18 +1,30 @@
-ROOTDEV= /dev/hd3
+#
+# if you want the ram-disk device, define this to be the
+# size in blocks.
+#
+RAMDISK = #-DRAMDISK=512
 
-AS86	=as -0 -a
-CC86	=cc -0
-LD86	=ld -0
+AS86	=as86 -0 -a
+LD86	=ld86 -0
 
 AS	=gas
 LD	=gld
 LDFLAGS	=-s -x -M
-CC	=gcc
-CFLAGS	=-Wall -O -fstrength-reduce -fomit-frame-pointer -fcombine-regs
+CC	=gcc $(RAMDISK)
+CFLAGS	=-Wall -O -fstrength-reduce -fomit-frame-pointer \
+-fcombine-regs -mstring-insns
 CPP	=cpp -nostdinc -Iinclude
 
+#
+# ROOT_DEV specifies the default root-device when making the image.
+# This can be either FLOPPY, /dev/xxxx or empty, in which case the
+# default of /dev/hd6 is used by 'build'.
+#
+ROOT_DEV=/dev/hd6
+
 ARCHIVES=kernel/kernel.o mm/mm.o fs/fs.o
 DRIVERS =kernel/blk_drv/blk_drv.a kernel/chr_drv/chr_drv.a
+MATH	=kernel/math/math.a
 LIBS	=lib/lib.a
 
 .c.s:
@@ -27,24 +39,30 @@ LIBS	=lib/lib.a
 all:	Image
 
 Image: boot/bootsect boot/setup tools/system tools/build
-	tools/build boot/bootsect boot/setup tools/system $(ROOTDEV) > Image
+	tools/build boot/bootsect boot/setup tools/system $(ROOT_DEV) > Image
 	sync
 
+disk: Image
+	dd bs=8192 if=Image of=/dev/PS0
+
 tools/build: tools/build.c
 	$(CC) $(CFLAGS) \
 	-o tools/build tools/build.c
-	chmem +65000 tools/build
 
 boot/head.o: boot/head.s
 
 tools/system:	boot/head.o init/main.o \
-		$(ARCHIVES) $(DRIVERS) $(LIBS)
+		$(ARCHIVES) $(DRIVERS) $(MATH) $(LIBS)
 	$(LD) $(LDFLAGS) boot/head.o init/main.o \
 	$(ARCHIVES) \
 	$(DRIVERS) \
+	$(MATH) \
 	$(LIBS) \
 	-o tools/system > System.map
 
+kernel/math/math.a:
+	(cd kernel/math; make)
+
 kernel/blk_drv/blk_drv.a:
 	(cd kernel/blk_drv; make)
 
@@ -63,30 +81,29 @@ fs/fs.o:
 lib/lib.a:
 	(cd lib; make)
 
-#boot/setup: boot/setup.s
-#	$(AS86) -o boot/setup.o boot/setup.s
-#	$(LD86) -s -o boot/setup boot/setup.o
+boot/setup: boot/setup.s
+	$(AS86) -o boot/setup.o boot/setup.s
+	$(LD86) -s -o boot/setup boot/setup.o
 
-#boot/bootsect:	tmp.s
-#	$(AS86) -o boot/bootsect.o tmp.s
-#	rm -f tmp.s
-#	$(LD86) -s -o boot/bootsect boot/bootsect.o
+boot/bootsect:	boot/bootsect.s
+	$(AS86) -o boot/bootsect.o boot/bootsect.s
+	$(LD86) -s -o boot/bootsect boot/bootsect.o
 
-#tmp.s:	boot/bootsect.s tools/system
-#	(echo -n "SYSSIZE = (";ls -l tools/system | grep system \
-#		| cut -c25-31 | tr '\012' ' '; echo "+ 15 ) / 16") > tmp.s
-#	cat boot/bootsect.s >> tmp.s
+tmp.s:	boot/bootsect.s tools/system
+	(echo -n "SYSSIZE = (";ls -l tools/system | grep system \
+		| cut -c25-31 | tr '\012' ' '; echo "+ 15 ) / 16") > tmp.s
+	cat boot/bootsect.s >> tmp.s
 
 clean:
-	rm -f Image System.map tmp_make core
-	rm -f init/*.o boot/*.o tools/system tools/build
+	rm -f Image System.map tmp_make core boot/bootsect boot/setup
+	rm -f init/*.o tools/system tools/build boot/*.o
 	(cd mm;make clean)
 	(cd fs;make clean)
 	(cd kernel;make clean)
 	(cd lib;make clean)
 
 backup: clean
-	(cd .. ; tar cf - linux | compress16 - > backup.Z)
+	(cd .. ; tar cf - linux | compress - > backup.Z)
 	sync
 
 dep: