1 files changed, 67 insertions, 0 deletions
diff --git a/kern/sched_asm.S b/kern/sched_asm.S
new file mode 100644
index 0000000..747598e
--- /dev/null
+++ b/kern/sched_asm.S
@@ -0,0 +1,67 @@
+/** @file sched_asm.S
+ *
+ *  @brief scheduling functions.
+ *
+ *  @author Hanjie Wu (hanjiew)
+ *  @bug No functional bugs
+ */
+
+#include <x86/seg.h>
+
+.text
+
+.global set_fs
+.type set_fs, %function
+set_fs:
+    push 0x4(%esp)
+    pop %fs
+    ret
+
+.macro PERCPU_GETSET name offset
+.global get_\name
+.type get_\name, %function
+get_\name:
+    xor %eax, %eax
+    mov %fs:\offset(%eax), %eax
+    ret
+
+.global set_\name
+.type set_\name, %function
+set_\name:
+    xor %esi, %esi
+    mov 0x4(%esp), %eax
+    mov %eax, %fs:\offset(%esi)
+    ret
+.endm
+
+PERCPU_GETSET current 0x0
+PERCPU_GETSET idle 0x4
+PERCPU_GETSET kthread 0x8
+PERCPU_GETSET mapped_phys_page 0xc
+PERCPU_GETSET mapped_phys_page_pte 0x10
+
+.global return_to_user
+.type return_to_user, %function
+return_to_user:
+    push %esp
+    call check_pending_exit
+    add $0x4, %esp
+    pop %gs /* restore from stack_frame_t structure */
+    pop %fs
+    pop %es
+    pop %ds
+    popa
+    iret
+
+.global switch_stack_cleanup
+.type switch_stack_cleanup, %function
+switch_stack_cleanup:
+    mov 0x8(%esp), %eax
+    mov 0x4(%esp), %esp
+    push %eax
+    call cleanup_dead_thread
+    add $0x4, %esp
+    pop %ebp
+    pop %ebx
+    popf
+    ret