Alan Cox has been replaced by a sh script. GNU too. I must admit though,
it's a whopping 115k.
I have a 32-bit self-booted program running on my B box that responds to
human input. The B box is a P2 Compaq I just picked up for $125--. I had a
spare monitor. The response from the program I'm working on is prompt and
consistant, but degenerate, and the program is written in a 386 assembler
written in Bash, so I've named the program "Durtro".
When you boot Durtro it puts a few boot-progress characters on the stock
VGA text screen, the cursor is wherever it was, and there's 4 cells of
junk in the upper mid-right of the screen. Those are the output of an
endless loop that polls IO ports 0x60 and 0x64 continuously. Interrupts
are still off, a20 hasn't actually been checked, etc. When you hit
keyboard keys the glyph in the left-most cell changes. I'd have to clean
up the joint to find a spare PS2 mouse, and that's out of the question, so
for now I'm getting my jollies with that left-most cell.
The changes to that cell visibly indicate how the BIOS left the keyboard
controller. The higher-scan-code keys wobble between glyphs when you hold
them down. Stuff like the "s" key doesn't. That's probably due to the
XT-era keys repeating the same byte when they repeat, while MF-2 stuff
sends a couple differing bytes per repeat, which makes for a visual
wobble. It looks like about a half-second delay before repeating. Capslock
is software; no light, just an ordinary glyph-twiddle. What I can see here
that you wouldn't be able to trust in e.g. /dev/port is that the byte in
0x60 just sits there for arbitrary reads until the keyboard sends another
one. And I just like a clean machine for such things. Ya never know unless
ya know.
There's more fun. It seems the PC keyboard controller is fully chording. I
mean FULLY. Well heck, it SHOULD be, having a microcontroller just for the
keyboard and all. Not to mention it's own serial protocol. Just because
they never use all that capability the C64 didn't have doesn't mean it's
not there. You can hold down 5 keys simultaneously with one hand and get
changes to my lovely little output character when you twiddle some sixth
key. It seems to usually work, but the downness of all 5 keys becomes
iffy. What's going on as far as repeating then is not clear. What is clear
is that if you want all the keyboard info fast, it's being produced.
Here's the osimplay analog to gas -a of Durtro. The threebies in the
actual-code column are octal. A separate program clips off the 0x7c00
zeros.
00000000 00... ALLOT 0x7C00
00007c00 270 50 02 = 592 to A
00007c03 271 01 00 = 1 to C
00007c06 31 322 XOR D with D
00007c08 273 00 7c = 0x7c00 to B
00007c0b cd 13 submit 0x13
00007c0d fa nosurprises
00007c0e 270 00 b8 = 0xb800 to A
00007c11 8e 330 = A to DS
00007c13 270 48 68 = 0x6848 to A
00007c16 89 006 20 02 = A to @ 544
00007c1a 31 300 XOR A with A
00007c1c 8e 330 = A to DS
00007c1e 0f 01 16 19 7d setGDT initial_gdtr
00007c23 270 00 b8 = 0xb800 to A
00007c26 8e 330 = A to DS
00007c28 270 61 61 = 0x6161 to A
00007c2b 89 006 c0 02 = A to @ 704
00007c2f 270 01 00 = 1 to A 0f 01 f0
00007c35 e9 00 00 jump PMODE16
00007c38 (O) PMODE16
00007c38 270 33 f2 = 0xf233 to A
00007c3b 89 006 60 03 = A to @ 864
00007c3f ea 44 7c 08 00 far jump addr./GDTindex ptr
00007c44 (O) BIG_CS
00007c44 270 4e 33 73 27 = 0x2773334e to A
00007c49 89 005 00 04 00 00 = A to @ 1024
00007c4f 270 10 00 00 00 = 0x10 to A
00007c54 8e 330 = A to DS
00007c56 (O) BIG_DS
00007c56 270 21 3a 6d 27 = 0x276d3a21 to A
00007c5b 89 005 a0 84 0b 00 = A to @ 754848
00007c61 31 300 XOR A with A
00007c63 8e 300 = A to ES
00007c65 8e 340 = A to FS
00007c67 8e 350 = A to GS
00007c69 (O) nullifiedextrasegments
00007c69 270 75 84 74 00 = 0x748475 to A
00007c6e 89 005 60 88 0b 00 = A to @ 755808
00007c74 270 10 00 00 00 = 0x10 to A
00007c79 8e 320 = A to SS
00007c7b 274 00 40 00 00 = 0x4000 to SP
00007c80 (O) A20_fix
00007c80 272 64 00 00 00 = 0x64 to D
00007c85 ec recieve byte
00007c86 a9 02 00 00 00 ANDtest 2 with A
00007c8b 0f 85 ef ff ff ff when not zero A20_fix
00007c91 (O) A20_again
00007c91 270 d1 00 00 00 = 0xd1 to A
00007c96 ee send byte
00007c97 ec recieve byte
00007c98 a9 02 00 00 00 ANDtest 2 with A
00007c9d 0f 85 ee ff ff ff when not zero A20_again
00007ca3 270 df 00 00 00 = 0xdf to A
00007ca8 272 60 00 00 00 = 0x60 to D
00007cad ee send byte
00007cae 0f 01 1d 8b 7d 00 00 setIDT 32139
00007cb5 (O) defaultallvectors
00007cb5 31 377 XOR DI with DI
00007cb7 270 76 7d 00 00 = unprepared to A
00007cbc (O) perIDTvector
00007cbc 60 pushcore
00007cbd e8 7d 00 00 00 call install
00007cc2 61 pullcore
00007cc3 107 1+ DI
00007cc4 81 377 7f 00 00 00 -test 127 with DI
00007cca 0f 85 ec ff ff ff when not zero perIDTvector
00007cd0 (O) initkeyboard
00007cd0 89 30 = to A
00007cd2 277 21 00 00 00 = 0x21 to DI
00007cd7 e8 63 00 00 00 call install
00007cdc (O) initNMIvector
00007cdc 277 02 00 00 00 = 2 to DI
00007ce1 89 30 = to A
00007ce3 e8 57 00 00 00 call install
00007ce8 (O) NMIoninCMOS
00007ce8 e4 70 recieve byte 112
00007cea 0d 80 00 00 00 OR 0x80 to A
00007cef e6 70 send byte 112
00007cf1 (O) theloop
00007cf1 272 60 00 00 00 = 0x60 to D
00007cf6 ec recieve byte
00007cf7 0d 00 43 22 33 OR 0x33224300 to A
00007cfc 89 005 00 81 0b 00 = A to @ 753920
00007d02 272 64 00 00 00 = 0x64 to D
00007d07 ec recieve byte
00007d08 0d 00 43 87 23 OR 0x23874300 to A
00007d0d 89 005 04 81 0b 00 = A to @ 753924
00007d13 e9 d9 ff ff ff jump theloop
00007d18 f4 halt
00007d19 (O) initial_gdtr
00007d19 00 02 1f 7d 00 00
00007d1f (O) GDT_templates
00007d1f 00 00 00 00 00 00 00 00
00007d27 ff ff 00 00 00 9a cf 00 index 1
00007d2f ff ff 00 00 00 92 cf 00 index 2 *4k BIG f-nybble
00007d37 ff ff 00 30 00 89 9f 00
00007d3f (O) install
00007d3f 273 01 00 00 00 = 1 to B
00007d44 271 0e 00 00 00 = 14 to C
00007d49 c1 347 03 upshift 3 to DI
00007d4c 03 075 00 00 00 00 + @ 0 to DI
00007d52 (O) makegate
00007d52 89 302 = A to D
00007d54 81 342 ff ff 00 00 AND 0x0000ffff to D
00007d5a c1 343 13 upshift 19 to B
00007d5d 09 332 OR B to D
00007d5f 89 027 = D to @ DI
00007d61 81 340 00 00 ff ff AND 0xffff0000 to A
00007d67 c1 341 08 upshift 8 to C
00007d6a 81 341 00 80 00 00 AND 0x8000 to C
00007d70 09 301 OR A to C
00007d72 89 137 04 = B to @ 4 DI
00007d75 c3 return
00007d76 (O) unprepared
00007d76 120 push A
00007d77 8b 005 62 82 0b 00 = @ 754274 to A
00007d7d 81 300 6f 00 00 00 + 111 to A
00007d83 89 005 62 82 0b 00 = A to @ 754274
00007d89 130 pull A
00007d8a cf dismiss
00007d8b (O) initial_IDTreg
00007d8b 00 02 00 00 00 00
00007d91 (O) PIC
00007d91 00... ALLOT
00007d91 (O) PICspec
00007d91 31 377 XOR DI with DI
00007d93 8b 075 91 7d 00 00 = @ 32145 to DI
00007d99 c1 347 03 upshift 3 to DI
00007d9c 81 307 43 00 00 00 + 0x43 to DI
00007da2 8b 005 91 7d 00 00 = @ 32145 to A
00007da8 c1 340 03 upshift 3 to A
00007dab 8b 005 91 7d 00 00 = @ 32145 to A
00007db1 c1 340 02 upshift 2 to A
00007db4 8b 005 91 7d 00 00 = @ 32145 to A
00007dba d3 340 upshift A
00007dbc ee send byte
00007dbd c3 return
00007dbe (O) writePICcount
00007dbe 31 377 XOR DI with DI
00007dc0 8b 075 91 7d 00 00 = @ 32145 to DI
00007dc6 c1 347 03 upshift 3 to DI
00007dc9 81 307 40 00 00 00 + 0x40 to DI
00007dcf 03 075 91 7d 00 00 + @ 32145 to DI
00007dd5 8b 005 91 7d 00 00 = @ 32145 to A
00007ddb ee send byte
00007ddc c1 350 08 downshift 8 to A
00007ddf ee send byte
00007de0 c3 return
00007de1 (O) ticks
00007de1 00... ALLOT 8
00007de9 (O) appendages
This, /Ha3sm/code/TOP, is vaguely analagous to init/main.c, along with
all of Linux's attendant obfuscations...
........................................................................
# init flow of control. _start/main()
. boot/fromfloppy
nosurprises
. boot/pmode
. boot/a20 # compembles, bus not checked yet
. interrupt/IDTinit
. keyboard/init # June 2003 no PS/2 mouse yet
. timer/pulse/init
L theloop
= 0x60 to D
recieve byte
OR 0x33224300 to A
= A to @ $((0xb8100))
= 0x64 to D
recieve byte
OR 0x23874300 to A
= A to @ $((0xb8104))
#. test/churn
jump theloop
halt
#############################################################
# outside main(). data and subroutines.
. boot/GDTdata
. interrupt/IDTroutines # install, unprepared
. timer/routines
. timer/pulse/ticker
#############################################################
L appendages
# wc keyboard/keycoordinates.b = 608
#if test $pass = 2 ;then#
#
#m#v binary inary
#
#cat inary keyboard/keycoordinates.b > binary
#
#rm inary#
#
#fi
......................................................................
The osimplay on my webpage isn't quite like this one. This one doesn't
have the app stuff like ELF and Linux syscalls, and more notably, the
"allocated" variable in that osimplay is problematic with kernel code.
That's for .bss, and I don't do no .bss.
Rick Hohensee
-- MOST: /owner//Durtro (229,1)
100%--------End of buffer.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Jun 30 2003 - 22:00:15 EST