From 0fbb43a96646c0d8d593f5d72b3cafc9b6ac4773 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 16 Nov 2025 16:38:26 -0500 Subject: kern/amd64: cpu: Disable master/slave i8259 chips Signed-off-by: Ian Moffett --- sys/arch/amd64/cpu/boot.S | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'sys/arch/amd64/cpu/boot.S') diff --git a/sys/arch/amd64/cpu/boot.S b/sys/arch/amd64/cpu/boot.S index 26b2b8b..0cda6a7 100644 --- a/sys/arch/amd64/cpu/boot.S +++ b/sys/arch/amd64/cpu/boot.S @@ -45,6 +45,15 @@ _start: call gdt_load /* Load our GDT */ call idt_load /* Load our IDT */ + /* + * RV7 will default to APIC operation, as per a section + * somewhere around 5.2.12 of the ACPI spec, we'll need + * to disable the PC-AT dual 8259 chips. + */ + mov $0xFF, %al /* Mask all inputs */ + out %al, $0x21 /* Disable the master PIC */ + out %al, $0xA1 /* Disable the slave PIC */ + lea bootmsg(%rip), %rdi call uart_puts -- cgit v1.2.3