Differential D25273 Diff 73792 sys/amd64/amd64/mpboot.S

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sys/amd64/amd64/mpboot.S

Show First 20 Lines • Show All 84 Lines • ▼ Show 20 Lines	jmp_32:
/*		/*
* At this point, we are running in 32 bit legacy protected mode.		* At this point, we are running in 32 bit legacy protected mode.
*/		*/
.code32		.code32
protmode:		protmode:
mov $bootdata-gdt, %eax		mov $bootdata-gdt, %eax
mov %ax, %ds		mov %ax, %ds

/* Turn on the PAE bit for when paging is enabled */		/* Turn on the PAE and optionally LA57 bit for when paging is enabled */
		alcUnsubmitted Done Inline Actions See earlier comment. alc: See earlier comment.
mov %cr4, %eax		mov %cr4, %eax
orl $CR4_PAE, %eax		orl $CR4_PAE, %eax
mov %eax, %cr4		cmpb $0, mptramp_la57-mptramp_start(%ebx)
		je 1f
		orl $CR4_LA57, %eax
		1: mov %eax, %cr4

/*		/*
* Enable EFER.LME so that we get long mode when all the prereqs are		* Enable EFER.LME so that we get long mode when all the prereqs are
* in place. In this case, it turns on when CR0_PG is finally enabled.		* in place. In this case, it turns on when CR0_PG is finally enabled.
* Pick up a few other EFER bits that we'll use need we're here.		* Pick up a few other EFER bits that we'll use need we're here.
*/		*/
movl $MSR_EFER, %ecx		movl $MSR_EFER, %ecx
rdmsr		rdmsr
Show All 22 Lines	1: mov %eax, %cr4
*/		*/
mov %cr0, %eax		mov %cr0, %eax
orl $CR0_PG, %eax		orl $CR0_PG, %eax
mov %eax, %cr0		mov %eax, %cr0

/*		/*
* At this point paging is enabled, and we are in "compatibility" mode.		* At this point paging is enabled, and we are in "compatibility" mode.
* We do another far jump to reload %cs with the 64 bit selector.		* We do another far jump to reload %cs with the 64 bit selector.
* %cr3 points to a 4-level page table page.		* %cr3 points to a 4- or 5-level page table page.
		alcUnsubmitted Done Inline Actions Drop the final "page" from this sentence. alc: Drop the final "page" from this sentence.
* We cannot yet jump all the way to the kernel because we can only		* We cannot yet jump all the way to the kernel because we can only
* specify a 32 bit linear address. So, yet another trampoline.		* specify a 32 bit linear address. So, yet another trampoline.
		alcUnsubmitted Done Inline Actions "So, we use yet another ..." alc: "So, we use yet another ..."
*		*
* The following instruction is:		* The following instruction is:
* ljmp $kernelcode-gdt, $tramp_64-mptramp_start		* ljmp $kernelcode-gdt, $tramp_64-mptramp_start
* but gas cannot assemble that. And besides, we patch the targets		* but gas cannot assemble that. And besides, we patch the targets
* in early startup and its a little clearer what we are patching.		* in early startup and its a little clearer what we are patching.
*/		*/
jmp_64:		jmp_64:
.byte 0xea /* opcode for far jump */		.byte 0xea /* opcode for far jump */
▲ Show 20 Lines • Show All 58 Lines • ▼ Show 20 Lines	gdtend:
/*		/*
* The address of our page table pages that the boot code		* The address of our page table pages that the boot code
* uses to trampoline up to kernel address space.		* uses to trampoline up to kernel address space.
*/		*/
.globl mptramp_pagetables		.globl mptramp_pagetables
mptramp_pagetables:		mptramp_pagetables:
.long 0		.long 0

		/* 5-level paging ? */
		.globl mptramp_la57
		mptramp_la57:
		.long 0

/*		/*
* The pseudo descriptor for lgdt to use.		* The pseudo descriptor for lgdt to use.
*/		*/
lgdt_desc:		lgdt_desc:
.word gdtend-gdt /* Length */		.word gdtend-gdt /* Length */
.long gdt-mptramp_start /* Offset plus %ds << 4 */		.long gdt-mptramp_start /* Offset plus %ds << 4 */

mptramp_end:		mptramp_end:
Show All 26 Lines	entry_64:
orl $EFER_NXE, %eax		orl $EFER_NXE, %eax
wrmsr		wrmsr

1:		1:
/*		/*
* Load a real %cr3 that has all the direct map stuff and switches		* Load a real %cr3 that has all the direct map stuff and switches
* off the 1GB replicated mirror. Load a stack pointer and jump		* off the 1GB replicated mirror. Load a stack pointer and jump
* into AP startup code in C.		* into AP startup code in C.
*/		*/
		cmpl $0, la57
		jne 2f
movq KPML4phys, %rax		movq KPML4phys, %rax
movq %rax, %cr3		jmp 3f
		2: movq KPML5phys, %rax
		3: movq %rax, %cr3
movq bootSTK, %rsp		movq bootSTK, %rsp
jmp init_secondary		jmp init_secondary