First Hello world syscall

kernel/amd64/intr_stub.S

@@ -1,4 +1,5 @@
 #include <amd64/intr_defs.h>
+#include <amd64/regsasm.h>
 
 .extern amd64_intr_handler
 
@@ -9,67 +10,20 @@
   pushq $0; \
   pushq $z;
 
-#define push_regs \
-  pushq %rax; \
-  pushq %rcx; \
-  pushq %rdx; \
-  pushq %rsi; \
-  pushq %rdi; \
-  pushq %rbp; \
-  pushq %rbx; \
-  pushq %r8; \
-  pushq %r9; \
-  pushq %r10; \
-  pushq %r11; \
-  pushq %r12; \
-  pushq %r13; \
-  pushq %r14; \
-  pushq %r15;
-
-#define pop_regs \
-  popq %r15; \
-  popq %r14; \
-  popq %r13; \
-  popq %r12; \
-  popq %r11; \
-  popq %r10; \
-  popq %r9; \
-  popq %r8; \
-  popq %rbx; \
-  popq %rbp; \
-  popq %rdi; \
-  popq %rsi; \
-  popq %rdx; \
-  popq %rcx; \
-  popq %rax;
-
 #define make_intr_stub(x, n) \
   .global amd64_intr ## n; \
   amd64_intr ## n:; \
   x(n); \
   cli; \
-  movq %rsp, %rax; \
-  movq 144(%rax), %rax; \
-  testb $3, %al; \
-  jz 1f; \
-  swapgs; \
-1:; \
   push_regs; \
   cld; \
   movq %rsp, %rdi; \
-  movq %rsp, %rax; \
+  movq %rsp, %rbp; \
   subq $8, %rsp; \
   andq $~0xF, %rsp; \
-  movq %rax, (%rsp); \
   callq amd64_intr_handler; \
-  movq (%rsp), %rsp; \
+  movq %rbp, %rsp; \
   pop_regs; \
-  movq %rsp, %rax; \
-  movq 144(%rax), %rax; \
-  testb $3, %al; \
-  jz 2f; \
-  swapgs; \
-2:; \
   addq $16, %rsp; \
   iretq;