1 files changed, 64 insertions, 0 deletions
diff --git a/boot/regs.zig b/boot/regs.zig
new file mode 100644
index 0000000..aedae99
--- /dev/null
+++ b/boot/regs.zig
@@ -0,0 +1,64 @@
+pub const Frame = extern struct {
+    r15: u64,
+    r14: u64,
+    r13: u64,
+    r12: u64,
+    r11: u64,
+    r10: u64,
+    r9: u64,
+    r8: u64,
+    rbp: u64,
+    rdi: u64,
+    rsi: u64,
+    rdx: u64,
+    rcx: u64,
+    rbx: u64,
+    rax: u64,
+    vector: u64,
+    error_code: u64,
+    // pushed by the cpu on the interrupt (long mode always pushes ss:rsp):
+    rip: u64,
+    cs: u64,
+    rflags: u64,
+    rsp: u64,
+    ss: u64,
+};
+
+// push/pop the 15 gprs in frames exact order (rax pushed first -> highest field,
+// r15 last -> at rsp = &frame). shared by every save/restore stub so they cant
+// drift from the frame layout above. `mov %rsp, %rdi` after push_gprs hands the
+// handler a *frame
+pub const PUSH_GPRS =
+    \\push %rax
+    \\push %rbx
+    \\push %rcx
+    \\push %rdx
+    \\push %rsi
+    \\push %rdi
+    \\push %rbp
+    \\push %r8
+    \\push %r9
+    \\push %r10
+    \\push %r11
+    \\push %r12
+    \\push %r13
+    \\push %r14
+    \\push %r15
+;
+pub const POP_GPRS =
+    \\pop %r15
+    \\pop %r14
+    \\pop %r13
+    \\pop %r12
+    \\pop %r11
+    \\pop %r10
+    \\pop %r9
+    \\pop %r8
+    \\pop %rbp
+    \\pop %rdi
+    \\pop %rsi
+    \\pop %rdx
+    \\pop %rcx
+    \\pop %rbx
+    \\pop %rax
+;