X-Git-Url: https://pd.if.org/git/?p=zos;a=blobdiff_plain;f=cpu.s;fp=cpu.s;h=30ca25e010420fc6ee6ee3ff8863f7cbc49846bd;hp=0000000000000000000000000000000000000000;hb=5a6d8336c11140500330da69cd74490a07876fe1;hpb=5c0e560e481e2e97b793f7574e849a5882781df9

diff --git a/cpu.s b/cpu.s
new file mode 100644
index 0000000..30ca25e
--- /dev/null
+++ b/cpu.s
@@ -0,0 +1,70 @@
+global readtsc:function
+global readmsr:function
+global writemsr:function
+global enable_syscall:function
+global disable_syscall:function
+global setdr0:function
+global setdr1:function
+global setdr2:function
+global setdr3:function
+global nextrip:function
+
+setdr0:
+	mov rax, dr0
+	mov dr0, rdi
+	ret
+
+setdr1:
+	mov rax, dr1
+	mov dr1, rdi
+	ret
+setdr2:
+	mov rax, dr2
+	mov dr2, rdi
+	ret
+setdr3:
+	mov rax, dr3
+	mov dr3, rdi
+	ret
+
+nextrip:
+	pop rax
+	push rax
+	ret
+	
+readtsc:
+	rdtsc
+	shl rdx, 32
+	or rax, rdx
+	ret
+
+writemsr:
+	; rdi is msr, rsi is value to write
+	mov ecx, edi
+	; edx is high order bits, eax is low order bits to write
+	mov eax, esi
+	shr rsi, 32
+	mov edx, esi
+	wrmsr
+	ret
+
+readmsr:
+	mov ecx, edi
+	rdmsr
+	shl rdx, 32
+	or rax, rdx
+
+%define EFER 0xc0000080
+enable_syscall:
+	mov ecx, EFER
+	rdmsr
+	or eax, 0x1
+	wrmsr
+	ret
+
+disable_syscall:
+	mov ecx, EFER
+	rdmsr
+	and eax, DWORD ~0x1
+	wrmsr
+	ret