minix/kernel/arch/i386/trampoline.S

#include <machine/asm.h>
#include "archconst.h"

.balign 4096
.text
.code16
ENTRY(trampoline)
	cli
	
	/* %cs has some value and we must use the same for data */
	mov	%cs, %ax
	mov	%ax, %ds

	/* load gdt and idt prepared by bsp */
	lgdtl	_C_LABEL(__ap_gdt) - _C_LABEL(trampoline)
	lidtl	_C_LABEL(__ap_idt) - _C_LABEL(trampoline)

	/* switch to protected mode */
	mov	%cr0, %eax
	orb	$1, %al
	mov	%eax, %cr0

	ljmpl	$CS_SELECTOR, $_C_LABEL(startup_ap_32)

.balign 4
LABEL(__ap_id)
.space 4
LABEL(__ap_gdt)
.space 8
LABEL(__ap_idt)
.space 8
LABEL(__trampoline_end)
SMP - We boot APs - kernel detects CPUs by searching ACPI tables for local apic nodes - each CPU has its own TSS that points to its own stack. All cpus boot on the same boot stack (in sequence) but switch to its private stack as soon as they can. - final booting code in main() placed in bsp_finish_booting() which is executed only after the BSP switches to its final stack - apic functions to send startup interrupts - assembler functions to handle CPU features not needed for single cpu mode like memory barries, HT detection etc. - new files kernel/smp.[ch], kernel/arch/i386/arch_smp.c and kernel/arch/i386/include/arch_smp.h - 16-bit trampoline code for the APs. It is executed by each AP after receiving startup IPIs it brings up the CPUs to 32bit mode and let them spin in an infinite loop so they don't do any damage. - implementation of kernel spinlock - CONFIG_SMP and CONFIG_MAX_CPUS set by the build system 2010-09-15 16:09:52 +02:00			`#include <machine/asm.h>`
			`#include "archconst.h"`

			`.balign 4096`
			`.text`
			`.code16`
			`ENTRY(trampoline)`
			`cli`

			`/* %cs has some value and we must use the same for data */`
			`mov %cs, %ax`
			`mov %ax, %ds`

			`/* load gdt and idt prepared by bsp */`
			`lgdtl _C_LABEL(__ap_gdt) - _C_LABEL(trampoline)`
			`lidtl _C_LABEL(__ap_idt) - _C_LABEL(trampoline)`

			`/* switch to protected mode */`
			`mov %cr0, %eax`
			`orb $1, %al`
			`mov %eax, %cr0`

SMP - kernel links again 2011-12-19 15:17:26 +01:00			`ljmpl $CS_SELECTOR, $_C_LABEL(startup_ap_32)`
SMP - We boot APs - kernel detects CPUs by searching ACPI tables for local apic nodes - each CPU has its own TSS that points to its own stack. All cpus boot on the same boot stack (in sequence) but switch to its private stack as soon as they can. - final booting code in main() placed in bsp_finish_booting() which is executed only after the BSP switches to its final stack - apic functions to send startup interrupts - assembler functions to handle CPU features not needed for single cpu mode like memory barries, HT detection etc. - new files kernel/smp.[ch], kernel/arch/i386/arch_smp.c and kernel/arch/i386/include/arch_smp.h - 16-bit trampoline code for the APs. It is executed by each AP after receiving startup IPIs it brings up the CPUs to 32bit mode and let them spin in an infinite loop so they don't do any damage. - implementation of kernel spinlock - CONFIG_SMP and CONFIG_MAX_CPUS set by the build system 2010-09-15 16:09:52 +02:00
			`.balign 4`
			`LABEL(__ap_id)`
			`.space 4`
			`LABEL(__ap_gdt)`
			`.space 8`
			`LABEL(__ap_idt)`
			`.space 8`
SMP - Kernel is loaded above 1M by default - the 16-bit trampoline must be within the first megabyte of physical memory thus the smp trampoline is copied explicitly below 1M 2010-09-15 16:10:00 +02:00			`LABEL(__trampoline_end)`