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MFi386: Attempt to reset the machine using the Reset Control register and

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Fast A20 and Init register if the keyboard reset doesn't work before
resorting to a triple fault.
This commit is contained in:
jhb 2007-04-24 20:06:36 +00:00
parent 9ff5fd9d6a
commit cafaaf6a39
1 changed files with 30 additions and 1 deletions
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31
sys/amd64/amd64/vm_machdep.c
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@ -457,6 +457,9 @@ cpu_reset()
static void
cpu_reset_real()
{
int b;
disable_intr();
/*
* Attempt to do a CPU reset via the keyboard controller,
@ -465,7 +468,33 @@ cpu_reset_real()
*/
outb(IO_KBD + 4, 0xFE);
DELAY(500000); /* wait 0.5 sec to see if that did it */
printf("Keyboard reset did not work, attempting CPU shutdown\n");
/*
* Attempt to force a reset via the Reset Control register at
* I/O port 0xcf9. Bit 2 forces a system reset when it is
* written as 1. Bit 1 selects the type of reset to attempt:
* 0 selects a "soft" reset, and 1 selects a "hard" reset. We
* try to do a "soft" reset first, and then a "hard" reset.
*/
outb(0xcf9, 0x2);
outb(0xcf9, 0x6);
DELAY(500000); /* wait 0.5 sec to see if that did it */
/*
* Attempt to force a reset via the Fast A20 and Init register
* at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
* Bit 0 asserts INIT# when set to 1. We are careful to only
* preserve bit 1 while setting bit 0. We also must clear bit
* 0 before setting it if it isn't already clear.
*/
b = inb(0x92);
if (b != 0xff) {
if ((b & 0x1) != 0)
outb(0x92, b & 0xfe);
outb(0x92, b | 0x1);
DELAY(500000); /* wait 0.5 sec to see if that did it */
}
printf("No known reset method worked, attempting CPU shutdown\n");
DELAY(1000000); /* wait 1 sec for printf to complete */
/* Force a shutdown by unmapping entire address space. */