Fix and simplify SMP

src/arch/x86_64/boot/entryother.asm

@@ -57,7 +57,7 @@ start32:
     mov     gs, ax
 
     ; Switch to the stack allocated by startothers()
-    mov     esp, [start-4]
+    mov     esp, [top - 4]
 
     call    enable_paging
 
@@ -77,7 +77,7 @@ spin:
 
 enable_paging:
     ; load P4 to cr3 register (cpu uses this to access the P4 table)
-    mov     eax, [start-8]
+    mov     eax, [top - 8]
     mov     cr3, eax
 
     ; enable PAE-flag in cr4 (Physical Address Extension)
@@ -109,7 +109,7 @@ start64:
     mov     gs, ax
 
     ; obtain kstack from data block before entryother
-    mov     rsp, [0x7000 - 16]
+    mov     rsp, [top - 16]
 
     mov     rax, other_main
     call    rax
@@ -136,4 +136,6 @@ gdt64:
     dq  (1<<43) | (1<<44) | (1<<47) | (1<<53) ; code segment
 .pointer:
     dw  $ - gdt64 - 1
-    dq  gdt64
+    dq  gdt64
+
+top: equ start + 0x1000

src/arch/x86_64/boot/linker.ld

@@ -6,14 +6,29 @@ KERNEL_OFFSET = 0xffffff0000000000;
 
 SECTIONS {
 
+  /* ensure that the multiboot header is at the beginning */
+
+  .multiboot_header :
+  {
+      KEEP(*(.multiboot_header))
+  }
+
+  /* bootloader for other processors */
+
+  . = OTHER_OFFSET;
+
+  .text.other : AT(OTHER_OFFSET)
+  {
+    KEEP(*/entryother.o (.text))
+    . = ALIGN(4K);
+  }
+
   /* bootloader for first processor */
 
   . = BOOT_OFFSET;
 
   .rodata.32 :
   {
-    /* ensure that the multiboot header is at the beginning */
-    KEEP(*(.multiboot_header))
     */boot.o (.rodata)
     . = ALIGN(4K);
   }
@@ -29,18 +44,6 @@ SECTIONS {
     . = ALIGN(4K);
   }
 
-  /* bootloader for other processors */
-
-  entryother_start = .;         /* backup va */
-  . = OTHER_OFFSET;
-  .text.other : AT(entryother_start)
-  {
-    KEEP(*/entryother.o (.text))
-    . = ALIGN(4K);
-  }
-  entryother_end = . - OTHER_OFFSET + entryother_start;
-  . = entryother_end;           /* recover va */
-
   /* kernel */
 
   . += KERNEL_OFFSET;

src/arch/x86_64/smp.rs

@@ -3,28 +3,21 @@ use memory::*;
 use core::ptr::{read_volatile, write_volatile};
 use x86_64::registers::control_regs::cr3;
 
-extern {
-    fn entryother_start();  // physical addr of entryother
-    fn entryother_end();
-}
-
 const ENTRYOTHER_ADDR: u32 = 0x7000;
 
 pub fn start_other_cores(acpi: &AcpiResult, ms: &mut MemorySet) {
     use consts::KERNEL_OFFSET;
-    ms.push(MemoryArea::new_identity(ENTRYOTHER_ADDR as usize - 1, ENTRYOTHER_ADDR as usize + 1, MemoryAttr::default(), "entry_other"));
-    ms.push(MemoryArea::new_identity(entryother_start as usize, entryother_start as usize + 1, MemoryAttr::default(), "entry_other"));
-    ms.push(MemoryArea::new_kernel(KERNEL_OFFSET, KERNEL_OFFSET + 1, MemoryAttr::default(), "entry_other3"));
-    copy_entryother();
+    ms.push(MemoryArea::new_identity(ENTRYOTHER_ADDR as usize, ENTRYOTHER_ADDR as usize + 1, MemoryAttr::default().execute(), "entry_other.text"));
+    ms.push(MemoryArea::new_kernel(KERNEL_OFFSET, KERNEL_OFFSET + 1, MemoryAttr::default(), "entry_other.ctrl"));
 
-    let args = unsafe{ &mut *(ENTRYOTHER_ADDR as *mut EntryArgs).offset(-1) };
+    let args = unsafe { &mut *(0x8000 as *mut EntryArgs).offset(-1) };
     for i in 1 .. acpi.cpu_num {
         let apic_id = acpi.cpu_acpi_ids[i as usize];
         let ms = MemorySet::new(7);
         *args = EntryArgs {
             kstack: ms.kstack_top() as u64,
-            page_table: ms._page_table_addr().0 as u32,
-            stack: 0x8000, // just enough stack to get us to entry64mp
+            page_table: cr3().0 as u32,
+            stack: args as *const _ as u32, // just enough stack to get us to entry64mp
         };
         unsafe { MS = Some(ms); }
         start_ap(apic_id, ENTRYOTHER_ADDR);
@@ -32,16 +25,6 @@ pub fn start_other_cores(acpi: &AcpiResult, ms: &mut MemorySet) {
     }
 }
 
-fn copy_entryother() {
-    use rlibc::memmove;
-    let entryother_start = entryother_start as usize;
-    let entryother_end = entryother_end as usize;
-    let size = entryother_end - entryother_start;
-    assert!(size <= 0x1000, "entryother code is too large, not supported.");
-    unsafe{ memmove(ENTRYOTHER_ADDR as *mut u8, entryother_start as *mut u8, size); }
-    debug!("smp: copied entryother code to 0x7000");
-}
-
 #[repr(C)]
 #[derive(Debug)]
 struct EntryArgs {

src/lib.rs

@@ -84,8 +84,7 @@ pub extern "C" fn rust_main(multiboot_information_address: usize) -> ! {
         kernel_memory.push(MemoryArea::new_identity(addr, addr + count * 0x1000, MemoryAttr::default(), "acpi"))
     });
 
-    // FIXME: PageFault when SMP
-//    arch::smp::start_other_cores(&acpi, &mut kernel_memory);
+    arch::smp::start_other_cores(&acpi, &mut kernel_memory);
     process::init(kernel_memory);
 
     fs::load_sfs();
@@ -128,8 +127,9 @@ pub extern "C" fn other_main() -> ! {
     arch::idt::init();
     arch::driver::apic::other_init();
     let cpu_id = arch::driver::apic::lapic_id();
-    println!("Hello world! from CPU {}!", arch::driver::apic::lapic_id());
     let ms = unsafe { arch::smp::notify_started(cpu_id) };
+    ms.switch();
+    println!("Hello world! from CPU {}!", arch::driver::apic::lapic_id());
 //    unsafe{ let a = *(0xdeadbeaf as *const u8); } // Page fault
     loop {}
 }