x86_64: move the pushing and popping common structs into a macro

* push/pop_preserved
* push/pop_scratch
* update the build system to recognise `.inc` assembly include files

:^)

Signed-off-by: Andy-Python-Programmer <[email protected]>

Author: Andy-Python-Programmer

src/aero_kernel/build.rs

@@ -25,9 +25,11 @@ use std::fs::DirEntry;
 use std::path::Path;
 use std::process::Command;
 
+//this is all magic, yes dont ever let anyone see this shit
+
 /// Helper function of walking the provided `dir`, only visiting files and calling
 /// `cb` on each file.
-fn visit_dirs(dir: &Path, cb: &dyn Fn(&DirEntry)) -> std::io::Result<()> {
+fn visit_dirs(dir: &Path, cb: &mut dyn FnMut(&DirEntry)) -> std::io::Result<()> {
     if dir.is_dir() {
         for entry in fs::read_dir(dir)? {
             let entry = entry?;
@@ -45,9 +47,11 @@ fn visit_dirs(dir: &Path, cb: &dyn Fn(&DirEntry)) -> std::io::Result<()> {
 }
 
 fn main() -> Result<(), Box<dyn Error>> {
+    let mut inc_files = vec![];
+
     // Assemble all of the assembly real files first as they will be included in the
     // source files using `incbin`.
-    visit_dirs(Path::new("src"), &|entry| {
+    visit_dirs(Path::new("src"), &mut |entry| {
         let path = entry.path();
 
         match path.extension() {
@@ -68,26 +72,52 @@ fn main() -> Result<(), Box<dyn Error>> {
                 assert!(success);
             }
 
+            Some(ext) if ext.eq(&OsString::from("inc")) => {
+                let path = path
+                    .to_str()
+                    .expect("invalud UTF-8 for file path (skill issue)");
+                inc_files.push(path.to_string())
+            }
+
             _ => (),
         }
     })?;
 
+    // more magic
+    inc_files = inc_files
+        .iter()
+        .map(|e| {
+            let e = e.split("/").collect::<Vec<_>>();
+            e[..e.len() - 1].join("/").to_string()
+        })
+        .collect::<Vec<_>>();
+
     // Now that we have assembled all of the real files, we can go ahead and assemble the source
     // files.
-    visit_dirs(Path::new("src"), &|entry: &DirEntry| {
+    visit_dirs(Path::new("src"), &mut |entry: &DirEntry| {
         let path = entry.path();
 
         match path.extension() {
             Some(ext) if ext.eq(&OsString::from("asm")) => {
                 let object_os = path.file_name().expect("Failed to get file name");
                 let object_file = object_os.to_str().expect("Invalid UTF-8 for file name");
 
-                nasm_rs::Build::new()
+                let mut build = nasm_rs::Build::new();
+
+                build
                     .file(&path)
                     .flag("-felf64")
-                    .target("x86_64-unknown-none")
+                    .target("x86_64-unknown-none");
+
+                println!("{:?}", inc_files);
+
+                for include in &inc_files {
+                    build.include(include);
+                }
+
+                build
                     .compile(object_file)
-                    .expect("Failed to compile assembly source file");
+                    .expect("failed to compile assembly: skill issue");
 
                 // Link it as a static library.
                 println!("cargo:rustc-link-lib=static={}", object_file);

src/aero_kernel/src/arch/x86_64/interrupts/handlers.asm

@@ -17,6 +17,8 @@
 
 bits 64
 
+%include "registers.inc"
+
 global interrupt_handlers
 
 extern generic_interrupt_handler
@@ -42,23 +44,9 @@ interrupt_handler_%1:
 
     xchg [rsp], rax
 
-    ; push the scratch registers
-    push rcx
-    push rdx
-    push rdi
-    push rsi
-    push r8
-    push r9
-    push r10
-    push r11
-
-    ; push the preserved registers
-    push rbx
-    push rbp
-    push r12
-    push r13
-    push r14
-    push r15
+    ; note: RAX is now on the top of the stack.
+    push_scratch
+    push_preserved
 
     push rax
 
@@ -71,24 +59,8 @@ interrupt_handler_%1:
     ; pop the error code
     add rsp, 8
 
-    ; pop the preserved registers
-    pop r15
-    pop r14
-    pop r13
-    pop r12
-    pop rbp
-    pop rbx
-
-    ; pop the scratch registers
-    pop r11
-    pop r10
-    pop r9
-    pop r8
-    pop rsi
-    pop rdi
-    pop rdx
-    pop rcx
-    pop rax
+    pop_preserved
+    pop_scratch
 
     ; `swapgs` if the interrupt has originated from ring 3 since currently
     ; the GS base points to the kernel per-cpu data.

src/aero_kernel/src/arch/x86_64/registers.inc

@@ -0,0 +1,49 @@
+; pops the preserved registers (the stack must have the preserved registers pushed on
+; top and matches the layout of the `PreservedRegisters` structure)
+%macro pop_preserved 0
+    pop r15
+    pop r14
+    pop r13
+    pop r12
+    pop rbp
+    pop rbx
+%endmacro
+
+; pops the scratch registers (the stack must have the scratch registers pushed on
+; top and matches the layout of the `ScratchRegisters` structure)
+%macro pop_scratch 0
+    pop r11
+    pop r10
+    pop r9
+    pop r8
+    pop rsi
+    pop rdi
+    pop rdx
+    pop rcx
+    pop rax
+%endmacro
+
+; pushes the scratch registers on the stack. The layout matches the layout of
+; the `ScratchRegisters` structure though note that it does not push the RAX
+; register. The caller is responsible for pushing RAX on the top of the stack.
+%macro push_scratch 0
+    push rcx
+    push rdx
+    push rdi
+    push rsi
+    push r8
+    push r9
+    push r10
+    push r11
+%endmacro
+
+; pushes the preserved registers on the stack. The layout matches the layout of
+; the `PreservedRegisters` structure.
+%macro push_preserved 0
+    push rbx
+    push rbp
+    push r12
+    push r13
+    push r14
+    push r15
+%endmacro

src/aero_kernel/src/arch/x86_64/syscall_handler.asm

@@ -15,6 +15,10 @@
 ; You should have received a copy of the GNU General Public License
 ; along with Aero. If not, see <https://www.gnu.org/licenses/>.
 
+bits 64
+
+%include "registers.inc"
+
 extern x86_64_do_syscall
 global x86_64_syscall_handler
 
@@ -60,24 +64,8 @@ x86_64_syscall_handler:
     push rcx                            ; push userspace return pointer
 
     push rax
-
-    ; push the scratch registers
-    push rcx
-    push rdx
-    push rdi
-    push rsi
-    push r8
-    push r9
-    push r10
-    push r11
-
-    ; push the preserved registers
-    push rbx
-    push rbp
-    push r12
-    push r13
-    push r14
-    push r15
+    push_scratch
+    push_preserved
 
     ; push a "fake" error code to match with the layout of the
     ; `InterruptErrorStack` structure.
@@ -92,24 +80,8 @@ x86_64_syscall_handler:
     ; pop the "fake" error code
     add rsp, 8
 
-    ; pop the preserved registers
-    pop r15
-    pop r14
-    pop r13
-    pop r12
-    pop rbp
-    pop rbx
-
-    ; pop the scratch registers
-    pop r11
-    pop r10
-    pop r9
-    pop r8
-    pop rsi
-    pop rdi
-    pop rdx
-    pop rcx
-    pop rax
+    pop_preserved
+    pop_scratch
 
     ; make the sysret frame
     pop rcx

src/aero_kernel/src/arch/x86_64/task.asm

@@ -15,6 +15,10 @@
 ; You should have received a copy of the GNU General Public License
 ; along with Aero. If not, see <https://www.gnu.org/licenses/>.
 
+bits 64
+
+%include "registers.inc"
+
 global jump_userland_exec
 global task_spinup
 global iretq_init
@@ -34,38 +38,27 @@ jump_userland_exec:
     swapgs
     o64 sysret
 
-fork_init:
-    cli
-    swapgs
-    jmp generic_iretq_init
-
 iretq_init:
     cli
-    jmp generic_iretq_init
 
-generic_iretq_init:
     ; pop the error code
     add rsp, 8
 
-    ; pop the preserved registers
-    pop r15
-    pop r14
-    pop r13
-    pop r12
-    pop rbp
-    pop rbx
+    pop_preserved
+    pop_scratch
 
-    ; pop the scratch registers
-    pop r11
-    pop r10
-    pop r9
-    pop r8
-    pop rsi
-    pop rdi
-    pop rdx
-    pop rcx
-    pop rax
+    iretq
+
+fork_init:
+    cli
 
+    ; pop the error code
+    add rsp, 8
+
+    pop_preserved
+    pop_scratch
+
+    swapgs
     iretq
 
 ; extern "C" fn task_spinup(prev: &mut Context, next: &mut Context)