entry.s

entry.s

uefi_entry_start:
.if longmode
	mov	uefi_entry_physoff(%rip),%rax
	call	uefi_entry_rip_plus_rax
	mov	uefi_entry_cr3(%rip),%rax
	mov	%rax,%cr3
	mov	uefi_entry_physoff(%rip),%rax
	add	$head-0x100000,%rax
	neg	%rax
	add	%rdi,%rax
	add	%rax,entry_pml4-DIFFPHYS(%rdi)
	add	%rax,entry_pdp+0-DIFFPHYS(%rdi)
	add	%rax,entry_pdp+8-DIFFPHYS(%rdi)
	mov	%rdi,%rax
	mov	$0x83,%al
	xor	%ebx,%ebx
1:
	mov	%rax,entry_pd-DIFFPHYS(%rdi,%rbx,8)
	add	$0x200000,%rax
	add	$1,%ebx
	cmp	$512,%ebx
	jb	1b
	lea	entry_pml4-DIFFPHYS(%rdi),%rax
	mov	%rax,%cr3
	mov	%edi,vmm_start_phys
	sgdtq	calluefi_uefi_gdtr
	sidtq	calluefi_uefi_idtr
	sldt	calluefi_uefi_ldtr
	mov	%es,calluefi_uefi_sregs+0
	mov	%cs,calluefi_uefi_sregs+2
	mov	%ss,calluefi_uefi_sregs+4
	mov	%ds,calluefi_uefi_sregs+6
	mov	%fs,calluefi_uefi_sregs+8
	mov	%gs,calluefi_uefi_sregs+10
	mov	uefi_entry_cr3(%rip),%rax
	mov	%rax,calluefi_uefi_cr3
	mov	$bss,%edi		# Clear BSS
	mov	$end+3,%ecx		#
	sub	%edi,%ecx		#
	shr	$2,%ecx			#
	xor	%eax,%eax		#
	cld				#
	rep	stosl			#
	mov	%cr4,%rcx
	or	$(CR4_PAE_BIT|CR4_PGE_BIT),%rcx
	and	$~CR4_MCE_BIT,%rcx
	mov	%cr3,%rax
	mov	%rcx,entry_cr4		# Save CR4
	mov	%rax,vmm_base_cr3	# Save CR3
	mov	%rcx,%cr4
	lgdtq	entry_gdtr		# Load GDTR
	ljmpl	*1f
1:
	.long	callmain64
	.long	ENTRY_SEL_CODE64
.else
	ret
.endif