1 //! 这个文件内放置初始内核线程的代码。 2 3 use core::sync::atomic::{compiler_fence, Ordering}; 4 5 use alloc::{ffi::CString, string::ToString}; 6 use log::{debug, error}; 7 use system_error::SystemError; 8 9 use crate::{ 10 arch::{interrupt::TrapFrame, process::arch_switch_to_user}, 11 driver::{net::e1000e::e1000e::e1000e_init, virtio::virtio::virtio_probe}, 12 filesystem::vfs::core::mount_root_fs, 13 net::net_core::net_init, 14 process::{kthread::KernelThreadMechanism, stdio::stdio_init, ProcessFlags, ProcessManager}, 15 smp::smp_init, 16 syscall::Syscall, 17 }; 18 19 use super::initcall::do_initcalls; 20 21 pub fn initial_kernel_thread() -> i32 { 22 kernel_init().unwrap_or_else(|err| { 23 panic!("Failed to initialize kernel: {:?}", err); 24 }); 25 26 switch_to_user(); 27 } 28 29 fn kernel_init() -> Result<(), SystemError> { 30 KernelThreadMechanism::init_stage2(); 31 kenrel_init_freeable()?; 32 33 // 由于目前加锁，速度过慢，所以先不开启双缓冲 34 // scm_enable_double_buffer().expect("Failed to enable double buffer"); 35 36 #[cfg(target_arch = "x86_64")] 37 crate::driver::disk::ahci::ahci_init().expect("Failed to initialize AHCI"); 38 virtio_probe(); 39 mount_root_fs().expect("Failed to mount root fs"); 40 e1000e_init(); 41 net_init().unwrap_or_else(|err| { 42 error!("Failed to initialize network: {:?}", err); 43 }); 44 45 debug!("initial kernel thread done."); 46 47 return Ok(()); 48 } 49 50 #[inline(never)] 51 fn kenrel_init_freeable() -> Result<(), SystemError> { 52 do_initcalls().unwrap_or_else(|err| { 53 panic!("Failed to initialize subsystems: {:?}", err); 54 }); 55 stdio_init().expect("Failed to initialize stdio"); 56 smp_init(); 57 58 return Ok(()); 59 } 60 61 /// 切换到用户态 62 #[inline(never)] 63 fn switch_to_user() -> ! { 64 let current_pcb = ProcessManager::current_pcb(); 65 66 // 删除kthread的标志 67 current_pcb.flags().remove(ProcessFlags::KTHREAD); 68 current_pcb.worker_private().take(); 69 70 *current_pcb.sched_info().sched_policy.write_irqsave() = crate::sched::SchedPolicy::CFS; 71 drop(current_pcb); 72 73 let mut trap_frame = TrapFrame::new(); 74 // 逐个尝试运行init进程 75 if try_to_run_init_process("/bin/dragonreach", &mut trap_frame).is_err() 76 && try_to_run_init_process("/bin/init", &mut trap_frame).is_err() 77 && try_to_run_init_process("/bin/sh", &mut trap_frame).is_err() 78 { 79 panic!("Failed to run init process: No working init found."); 80 } 81 82 // 需要确保执行到这里之后，上面所有的资源都已经释放（比如arc之类的） 83 compiler_fence(Ordering::SeqCst); 84 85 unsafe { arch_switch_to_user(trap_frame) }; 86 } 87 88 fn try_to_run_init_process(path: &str, trap_frame: &mut TrapFrame) -> Result<(), SystemError> { 89 if let Err(e) = run_init_process(path, trap_frame) { 90 if e != SystemError::ENOENT { 91 error!( 92 "Failed to run init process: {path} exists but couldn't execute it (error {:?})", 93 e 94 ); 95 } 96 return Err(e); 97 } 98 Ok(()) 99 } 100 101 fn run_init_process(path: &str, trap_frame: &mut TrapFrame) -> Result<(), SystemError> { 102 let argv = vec![CString::new(path).unwrap()]; 103 let envp = vec![CString::new("PATH=/").unwrap()]; 104 105 compiler_fence(Ordering::SeqCst); 106 Syscall::do_execve(path.to_string(), argv, envp, trap_frame)?; 107 Ok(()) 108 } 109