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- commit patch from David Haslam <dch@sirius.clara.co.uk> 

posted to bochs-developers on Wed, 29 Aug 2001 00:08:45 +0100

  David Haslam wrote:
  > I have been looking at the keyboard problem with Minix, which for
  > those that haven't tried Minix results in every key press giving the
  > response: ^@
  >
  > I am aware of the comments in the changelog that suggest removing 2
  > keyboard ACKs in iodev/keyboard.cc, but this is a bit of a hack,
  > (which is presumably why it was never incorporated).
  >
  > The problem seems to be that the Minix keyboard driver doesn't obey
  > the rules, and Bochs doesn't model the 8042 accurately. When issuing
  > commands to set the LEDs, Minix polls the 8042 output data register
  > waiting for an ACK even though the OBF flag isn't set.
  >
  > Bochs returns zero under these circumstances, which seems to
  > trigger obscure behaviour that messes up the Minix internal
  > keyboard queue. I don't fully understand why Minix breaks, but I
  > think the fact that the ACK generates an interrupt, and Minix treats
  > it as a scan code also has something to do with it.
  >
  > In any case, I believe, the fix is for Bochs to return the output
  > buffer contents, regardless of whether the OBF flag (called outb in
  > Bochs) is set.
  >
  > I expect the real hardware allows the register to be read at anytime,
  > and with this fix we are modelling the behaviour of the hardware more
  > accurately.
  >
  > I have tested it with Minix 2.0.0. Also DOS 6.22 still works after this fix.
  > Does anyone think this will break anything else?
  >
  > This diff is against the latest CVS of iodev/keyboard.cc, version 1.29
  > The last part of the diff is a minor fix to an unrelated debug print.
This commit is contained in:
Bryce Denney 2001-09-11 16:49:54 +00:00
parent fabdff5a16
commit 55ed69273b
1 changed files with 4 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
bochs/iodev/keyboard.cc
View File

@ -57,7 +57,7 @@ bx_keyb_c::bx_keyb_c(void)
memset( &s, 0, sizeof(s) );
BX_KEY_THIS put("KBD");
BX_KEY_THIS settype(KBDLOG);
BX_DEBUG(("Init $Id: keyboard.cc,v 1.30 2001-08-31 22:02:29 fries Exp $"));
BX_DEBUG(("Init $Id: keyboard.cc,v 1.31 2001-09-11 16:49:54 bdenney Exp $"));
}
bx_keyb_c::~bx_keyb_c(void)
@ -92,7 +92,7 @@ bx_keyb_c::resetinternals(Boolean powerup)
void
bx_keyb_c::init(bx_devices_c *d, bx_cmos_c *cmos)
{
BX_DEBUG(("Init $Id: keyboard.cc,v 1.30 2001-08-31 22:02:29 fries Exp $"));
BX_DEBUG(("Init $Id: keyboard.cc,v 1.31 2001-09-11 16:49:54 bdenney Exp $"));
Bit32u i;
BX_KEY_THIS devices = d;
@ -233,7 +233,6 @@ bx_keyb_c::read(Bit32u address, unsigned io_len)
}
else if (BX_KEY_THIS s.kbd_controller.outb) { /* kbd byte available */
val = BX_KEY_THIS s.kbd_controller.kbd_output_buffer;
BX_KEY_THIS s.kbd_controller.kbd_output_buffer = 0;
// BX_INFO(("kbd: %04d outb 0 auxb 0",__LINE__)); // das
BX_KEY_THIS s.kbd_controller.outb = 0;
BX_KEY_THIS s.kbd_controller.auxb = 0;
@ -262,7 +261,7 @@ bx_keyb_c::read(Bit32u address, unsigned io_len)
else {
BX_DEBUG(("num_elements = %d", BX_KEY_THIS s.kbd_internal_buffer.num_elements));
BX_DEBUG(("read from port 60h with outb empty"));
val = 0;
val = BX_KEY_THIS s.kbd_controller.kbd_output_buffer;
RETURN(val);
}
}
@ -915,7 +914,7 @@ bx_keyb_c::mouse_enQ(Bit8u mouse_data)
void
bx_keyb_c::kbd_ctrl_to_kbd(Bit8u value)
{
BX_DEBUG(("controller passed byte %02xh to keyboard"));
BX_DEBUG(("controller passed byte %02xh to keyboard", value));
if (BX_KEY_THIS s.kbd_internal_buffer.expecting_typematic) {
BX_KEY_THIS s.kbd_internal_buffer.expecting_typematic = 0;