diff options
| -rw-r--r-- | sys/amd64/amd64/vm_machdep.c | 11 | ||||
| -rw-r--r-- | sys/i386/i386/vm_machdep.c | 11 |
2 files changed, 14 insertions, 8 deletions
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index c181d42..adddc1c 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -466,10 +466,13 @@ cpu_reset_real() /* * 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. + * I/O port 0xcf9. Bit 2 forces a system reset when it + * transitions from 0 to 1. Bit 1 selects the type of reset + * to attempt: 0 selects a "soft" reset, and 1 selects a + * "hard" reset. We try a "hard" reset. The first write sets + * bit 1 to select a "hard" reset and clears bit 2. The + * second write forces a 0 -> 1 transition in bit 2 to trigger + * a reset. */ outb(0xcf9, 0x2); outb(0xcf9, 0x6); diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index 81e6374..71a9952 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -643,10 +643,13 @@ cpu_reset_real() /* * 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. + * I/O port 0xcf9. Bit 2 forces a system reset when it + * transitions from 0 to 1. Bit 1 selects the type of reset + * to attempt: 0 selects a "soft" reset, and 1 selects a + * "hard" reset. We try a "hard" reset. The first write sets + * bit 1 to select a "hard" reset and clears bit 2. The + * second write forces a 0 -> 1 transition in bit 2 to trigger + * a reset. */ outb(0xcf9, 0x2); outb(0xcf9, 0x6); |
