Kernel: Support starting up secondary processors on x86_64

Kernel/Arch/x86/x86_64/Boot/boot.S

@@ -354,6 +354,12 @@ apic_ap_start32:
  movl (ap_cpu_init_cr3 - apic_ap_start)(%ebp), %eax
  movl %eax, %cr3
 
+ /* Enter Long-mode! ref(https://wiki.osdev.org/Setting_Up_Long_Mode)*/
+ mov $0xC0000080, %ecx /* Set the C-register to 0xC0000080, which is the EFER MSR.*/
+ rdmsr /* Read from the model-specific register.*/
+ or $(1 << 8), %eax /* Set the LM-bit which is the 9th bit (bit 8).*/
+ wrmsr /* Write to the model-specific register.*/
+
  /* enable PAE + PSE */
  movl %cr4, %eax
  orl $0x60, %eax
@@ -364,48 +370,59 @@ apic_ap_start32:
  orl $0x80000000, %eax
  movl %eax, %cr0
 
- /* load a second temporary gdt that points above 3GB */
- lgdt (ap_cpu_gdtr_initial2 - apic_ap_start + 0xc0008000)
+ /* load the temporary 64-bit gdt from boot that points above 3GB */
+ lgdt gdt64ptr
 
  /* jump above 3GB into our identity mapped area now */
- ljmp $8, $(apic_ap_start32_2 - apic_ap_start + 0xc0008000)
-apic_ap_start32_2:
+ ljmpl $code64_sel, $(apic_ap_start64 - apic_ap_start + 0xc0008000)
+.code64
+apic_ap_start64:
+ mov $0, %ax
+ mov %ax, %ss
+ mov %ax, %ds
+ mov %ax, %es
+ mov %ax, %fs
+ mov %ax, %gs
+
  /* flush the TLB */
- movl %cr3, %eax
- movl %eax, %cr3
+ movq %cr3, %rax
+ movq %rax, %cr3
 
  movl $0xc0008000, %ebp
 
  /* now load the final gdt and idt from the identity mapped area */
- movl (ap_cpu_gdtr - apic_ap_start)(%ebp), %eax
- lgdt (%eax)
- movl (ap_cpu_idtr - apic_ap_start)(%ebp), %eax
- lidt (%eax)
+ movq (ap_cpu_gdtr - apic_ap_start)(%rbp), %rax
+ lgdt (%rax)
+ movq (ap_cpu_idtr - apic_ap_start)(%rbp), %rax
+ lidt (%rax)
 
  /* set same cr0 and cr4 values as the BSP */
- movl (ap_cpu_init_cr0 - apic_ap_start)(%ebp), %eax
- movl %eax, %cr0
- movl (ap_cpu_init_cr4 - apic_ap_start)(%ebp), %eax
- movl %eax, %cr4
+ movq (ap_cpu_init_cr0 - apic_ap_start)(%rbp), %rax
+ movq %rax, %cr0
+ movq (ap_cpu_init_cr4 - apic_ap_start)(%rbp), %rax
+ movq %rax, %cr4
 
  /* push the Processor pointer this CPU is going to use */
- movl (ap_cpu_init_processor_info_array - apic_ap_start)(%ebp), %eax
- addl $0xc0000000, %eax
- movl 0(%eax, %esi, 4), %eax
- push %eax
+ movq (ap_cpu_init_processor_info_array - apic_ap_start)(%ebp), %rax
+ movq $0xc0000000, %r8
+ addq %r8, %rax
+ movq 0(%rax, %rsi, 4), %rax
+ push %rax
 
  /* push the cpu id, 0 representing the bsp and call into c++ */
- incl %esi
- push %esi
+ incq %rsi
+ push %rsi
 
  xor %ebp, %ebp
  cld
 
  /* We are in identity mapped P0x8000 and the BSP will unload this code
  once all APs are initialized, so call init_ap but return to our
  infinite loop */
- push $loop
- ljmp $8, $init_ap
+ movabs $loop, %rax
+ pushq %rax
+ movabs $init_ap, %rax
+ jmp *(%rax)
 
 .align 4
 .global apic_ap_start_size
@@ -427,27 +444,24 @@ ap_cpu_gdt_end:
 ap_cpu_gdtr_initial:
  .2byte ap_cpu_gdt_end - ap_cpu_gdt - 1
  .4byte (ap_cpu_gdt - apic_ap_start) + 0x8000
-ap_cpu_gdtr_initial2:
- .2byte ap_cpu_gdt_end - ap_cpu_gdt - 1
- .4byte (ap_cpu_gdt - apic_ap_start) + 0xc0008000
 .global ap_cpu_gdtr
 ap_cpu_gdtr:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_idtr
 ap_cpu_idtr:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_init_cr0
 ap_cpu_init_cr0:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_init_cr3
 ap_cpu_init_cr3:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_init_cr4
 ap_cpu_init_cr4:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_init_processor_info_array
 ap_cpu_init_processor_info_array:
- .4byte 0x0 /* will be set at runtime */
+ .8byte 0x0 /* will be set at runtime */
 .global ap_cpu_init_stacks
 ap_cpu_init_stacks:
  /* array of allocated stack pointers */

Kernel/init.cpp

@@ -88,7 +88,7 @@ static void setup_serial_debug();
 // boot.S expects these functions to exactly have the following signatures.
 // We declare them here to ensure their signatures don't accidentally change.
 extern "C" void init_finished(u32 cpu) __attribute__((used));
-extern "C" [[noreturn]] void init_ap(u32 cpu, Processor* processor_info);
+extern "C" [[noreturn]] void init_ap(FlatPtr cpu, Processor* processor_info);
 extern "C" [[noreturn]] void init();
 
 READONLY_AFTER_INIT VirtualConsole* tty0;
@@ -194,7 +194,7 @@ extern "C" [[noreturn]] UNMAP_AFTER_INIT void init()
 //
 // The purpose of init_ap() is to initialize APs for multi-tasking.
 //
-extern "C" [[noreturn]] UNMAP_AFTER_INIT void init_ap(u32 cpu, Processor* processor_info)
+extern "C" [[noreturn]] UNMAP_AFTER_INIT void init_ap(FlatPtr cpu, Processor* processor_info)
 {
  processor_info->early_initialize(cpu);