lots and lots of userspace stuff

1 files changed, 32 insertions, 0 deletions

diff --git a/euler/source/syscall.asm b/euler/source/syscall.asm
new file mode 100644
index 0000000..d4515bb
--- /dev/null
+++ b/euler/source/syscall.asm
@@ -0,0 +1,32 @@
+bits 64
+
+section .text
+
+global __euler_do_syscall
+__euler_do_syscall:
+
+  push rdi
+  push rsi
+  push rdx
+  push rcx
+
+  mov rax, qword [rdi]
+  mov rdi, qword [rsi]
+  mov rsi, qword [rdx]
+  mov rdx, qword [rcx]
+
+  syscall
+
+  pop rcx
+  mov qword [rcx], rdx
+
+  pop rdx
+  mov qword [rdx], rsi
+
+  pop rsi
+  mov qword [rsi], rdi
+
+  pop rdi
+  mov qword [rdi], rax
+
+  ret