modularity

src/kernel/arch/mod.rs

@@ -15,6 +15,7 @@ compile_error!(
 pub mod x86_64;
 #[cfg(target_arch = "x86_64")]
 pub use x86_64::asm;
+pub use x86_64::startup;
 
 #[cfg(target_arch = "aarch64")]
 pub mod aarch64;

src/kernel/arch/x86_64/mod.rs

@@ -8,3 +8,4 @@ pub mod gdt;
 pub mod intel_virt;
 pub mod interrupts;
 pub mod serial;
+pub mod startup;

src/kernel/arch/x86_64/startup.rs

@@ -0,0 +1,42 @@
+use x86_64::{VirtAddr, registers::rflags::RFlags, structures::idt::InterruptStackFrameValue};
+
+use crate::{
+    arch::{
+        asm::ltr,
+        x86_64::{gdt::SELECTORS, interrupts::IDT},
+    },
+    log::{LOGGER, LogLevel},
+    log_info,
+    memory::alloc::format,
+};
+
+pub fn init() -> Result<(), ()> {
+    // Ensure GDT exists
+    SELECTORS.gdt.load();
+    log_info!("GDT loaded!");
+    // Load IDT
+    IDT.load();
+    log_info!("IDT loaded!");
+    x86_64::registers::model_specific::Star::write(
+        SELECTORS.sel_user_code,
+        SELECTORS.sel_user_stack,
+        SELECTORS.sel_kernel_code,
+        SELECTORS.sel_kernel_stack,
+    )
+    .expect("Segment order in GDT is bad");
+    ltr(SELECTORS.sel_tss.index());
+    Ok(())
+}
+
+pub fn jump_to_usermode(sp: VirtAddr, ip: VirtAddr) -> ! {
+    unsafe {
+        InterruptStackFrameValue::new(
+            ip,
+            SELECTORS.sel_user_code,
+            RFlags::INTERRUPT_FLAG,
+            sp,
+            SELECTORS.sel_user_stack,
+        )
+        .iretq();
+    }
+}

src/kernel/main.rs

@@ -18,7 +18,6 @@ mod util;
 
 use core::ptr::addr_of;
 
-use arch::x86_64::interrupts::IDT;
 use arch::x86_64::serial::SerialPort;
 use boot::{BASE_REVISION, params, *};
 use constants::*;
@@ -31,16 +30,10 @@ use limine::firmware::{
     FIRMWARE_TYPE_EFI32, FIRMWARE_TYPE_EFI64, FIRMWARE_TYPE_SBI, FIRMWARE_TYPE_X86BIOS,
 };
 use spin::mutex::Mutex;
-use x86_64::{VirtAddr, registers::rflags::RFlags, structures::idt::InterruptStackFrameValue};
+use x86_64::VirtAddr;
 
 use crate::{
-    arch::{
-        asm::ltr,
-        x86_64::{
-            cpuid::{CPUID, virt_supported},
-            gdt::SELECTORS,
-        },
-    },
+    arch::x86_64::cpuid::{CPUID, virt_supported},
     boot::modules::MODULE_RESPONSE,
     memory::paging::active_root_table,
 };
@@ -79,31 +72,22 @@ unsafe extern "C" fn main() -> ! {
             LOGGER.lock().add_device(Box::new(serial_logger));
         }
         log_trace!("Configured kernel logging devices");
+        let log_level = LOGGER.lock().level;
+        log_info!("Log level: {:?}", log_level);
     }
 
     // END OF CRITICAL AREA
     // Fallible code can be placed below this comment
 
+    let _ = arch::startup::init();
     // Initialize all statics so the bootloader memory can be reclaimed
     memory::init_statics();
 
-    // Ensure IDT exists
-    SELECTORS.gdt.load();
-    log_info!("GDT loaded!");
-    IDT.load();
-    log_info!("IDT loaded!");
-
     log_info!(
-        "Kernel cmdline: {}",
+        "Boot cmdline: {} {}",
+        EXECUTABLE_FILE_RESPONSE.executable_file().path(),
         EXECUTABLE_FILE_RESPONSE.executable_file().cmdline()
     );
-    log_info!(
-        "Kernel file path: {}",
-        EXECUTABLE_FILE_RESPONSE.executable_file().path()
-    );
-
-    let log_level = log::LOGGER.lock().level;
-    log_info!("Log level: {:?}", log_level);
 
     // Branding
     for line in ASCII_LOGO {
@@ -181,19 +165,12 @@ unsafe extern "C" fn main() -> ! {
     }
     log_info!("Virtualization provider: {:?}", virt_supported());
 
-    {
-        let root_ptable_info = unsafe { active_root_table() };
-        log_info!(
-            "Root page table is Level {} at 0x{:x}",
-            root_ptable_info.1,
-            addr_of!(*root_ptable_info.0) as usize
-        );
-        // This is an expensive function. Only run it if we're actually logging the results.
-        //let loglevel = LOGGER.lock().level;
-        //if loglevel <= LogLevel::Trace {
-        //    paging::walk_tables();
-        //}
-    }
+    let root_ptable_info = unsafe { active_root_table() };
+    log_info!(
+        "Root page table is Level {} at 0x{:x}",
+        root_ptable_info.1,
+        addr_of!(*root_ptable_info.0) as usize
+    );
 
     if let Some(modules_list) = *MODULE_RESPONSE
         && modules_list.modules()[0].path().ends_with("/userboot.bin")
@@ -201,40 +178,9 @@ unsafe extern "C" fn main() -> ! {
         let ub = modules_list.modules()[0];
         log_info!("Found userboot: {} {}", ub.path(), ub.cmdline());
 
-        //let start_addr = VirtAddr::from_ptr(ub.data() as *const [u8]);
-        let start_addr = VirtAddr::from_ptr(usermode_fn as *const fn());
-        log_info!("Start address: 0x{:x}", start_addr);
-
-        x86_64::registers::model_specific::Star::write(
-            SELECTORS.sel_user_code,
-            SELECTORS.sel_user_stack,
-            SELECTORS.sel_kernel_code,
-            SELECTORS.sel_kernel_stack,
-        )
-        .expect("fuck");
-        ltr(SELECTORS.sel_tss.index());
-        unsafe {
-            InterruptStackFrameValue::new(
-                VirtAddr::from_ptr(usermode_fn as *const fn()),
-                SELECTORS.sel_user_code,
-                RFlags::INTERRUPT_FLAG,
-                VirtAddr::new(0xffffffff80000000),
-                SELECTORS.sel_user_stack,
-            )
-            .iretq();
-        }
-    }
-
-    // TODO:
-    // - Map APIC
-    // - Create an interrupt stack frame, push it to stack, and iret to userboot
-
-    panic!("Finished boot, but cannot start init because processes not implemented!");
-}
-
-fn usermode_fn() -> ! {
-    log_info!("In usermode!");
-    loop {
-        arch::asm::nop();
+        let start_addr = VirtAddr::from_ptr(ub.data() as *const [u8]);
+        arch::startup::jump_to_usermode(VirtAddr::new(0xfffffff800000000), start_addr)
+    } else {
+        panic!("Userboot not found, cannot boot!");
     }
 }