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Diffstat (limited to 'na/kernel/main.cc')
| -rw-r--r-- | na/kernel/main.cc | 468 |
1 files changed, 0 insertions, 468 deletions
diff --git a/na/kernel/main.cc b/na/kernel/main.cc deleted file mode 100644 index db5843c..0000000 --- a/na/kernel/main.cc +++ /dev/null @@ -1,468 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* Copyright (C) 2026 Richard Qin */ - -/* - * LumeOS Kernel Main Entry — Global Initialization Sequence - * - * All CPUs enter kernel_main() after the assembly bootstrap (entry.S) - * has enabled MMU, cleared BSS, and called early_cpp_init(). - * - * BSP (cpu_id == 0) executes the full subsystem initialization DAG. - * APs spin on ap_boot_sync, then perform per-CPU init only. - * - * Boot DAG invariants (docs/specs/linux_abi_mm_plan.md §Boot Sequence): - * - trap_init() MUST precede any allocator (exception safety net) - * - sched_init() MUST precede timer_init() (software before hardware) - * - PID 1 (init) is spawned before entering idle loop - * - * Reference: docs/specs/global_init.md - */ - -#include <arch/config.h> -#include <arch/cpu.h> -#include <arch/extable.h> -#include <arch/sbi.h> -#include <lume/addr.h> -#include <lume/atomic.h> -#include <lume/console.h> -#include <lume/driver.h> -#include <lume/fdt.h> -#include <lume/fdtable.h> -#include <lume/fs_struct.h> -#include <lume/fs_types.h> -#include <lume/irq.h> -#include <lume/kernel_map.h> -#include <lume/klog.h> -#include <lume/kprintf.h> -#include <lume/memblock.h> -#include <lume/mount.h> -#include <lume/page_cache.h> -#include <lume/pmm.h> -#include <lume/random.h> -#include <lume/sched.h> -#include <lume/smp.h> -#include <lume/task.h> -#include <lume/pid.h> -#include <lume/pgrp.h> -#include <lume/signal.h> -#include <lume/signal_types.h> -#include <lume/trap.h> -#include <lume/types.h> - -// Declared by entry.S: the hart ID that won BSP election -extern "C" uint32 bsp_hart_id; - -// Linker symbol: kernel entry point (physical start address) -extern "C" char _start[]; - -// ============================================================ -// Forward declarations for subsystem init functions. -// Each is implemented by its owning module. On failure they -// call kernel_panic() directly — no error return. -// ============================================================ - -// BSP global init (strict order) -void console_init(); // 1. UART ready; kprintf/panic can output -void fdt_init(uint64 fdt_paddr); // 2. Parse FDT, build device node table -void pmm_init(); // 3. Buddy allocator ready -void slab_init(); // 4. kmem_cache ready; operator new usable -void vmm_init(); // 5. Fine-grained kernel page table; retire early_pgdir -void task_init(); // 6. PID allocator + global task list -void pgrp_init(); // 6.5. Process group hash table -void sched_init(); // 7. Create BSP Idle Task, init ready queues -void timer_init(); // 8. Configure timer interrupt (scheduler tick) -void syscall_init(); // 9. Register syscall jump table -void super_init(); // 10. VFS superblock registry -void ramfs_init(); // 11. RamFS filesystem registration -void vfs_init(); // 12. Mount root filesystem -void cdev_init(); // 13. Character device registry -void console_cdev_init(); // 14. Register console/null/zero cdevs -void devfs_init(); // 15. Create /dev and populate nodes -void tty_init(); // 15.5. TTY subsystem (console TTY + UART RX IRQ) -void populate_rootfs(); // 15.6. Unpack embedded initramfs CPIO into ramfs - -// Boot self-test runner -void selftest_run_all(); - -// AP per-CPU init -void vmm_init_ap(); // Switch to BSP-built kernel page table -void timer_init_ap(); // Start this CPU's timer interrupt -void sched_init_ap(); // Init per-CPU ready queue, create Idle Task - -// kthread_create from task.cc -extern TaskControlBlock *kthread_create(const char *name, void (*entry)(void *), - void *arg, uint8 priority); - -// ============================================================ -// PID 1 — init thread -// ============================================================ -static void init_thread_func(void *) { - printk(KERN_INFO "[init] PID 1 started\n"); - - /* Run post-SMP tests — APs are online by now */ - extern void selftest_smp(); - kprintf("\n========================================\n"); - kprintf(" Post-SMP Test Suite\n"); - kprintf("========================================\n"); - selftest_smp(); - kprintf("========================================\n"); - kprintf(" Post-SMP tests PASSED\n"); - kprintf("========================================\n\n"); - - /* - * Set up init's own VFS context (like Linux kernel_init). - * kthread_create does NOT inherit files/fs, so init creates its own. - */ - TaskControlBlock *self = current_task(); - - if (!self->files) { - self->files = alloc_files_struct(); - if (!self->files) { - printk(KERN_ERR "[init] failed to allocate files_struct\n"); - goto out; - } - } - if (!self->fs) { - self->fs = alloc_fs_struct(); - if (!self->fs) { - printk(KERN_ERR "[init] failed to allocate fs_struct\n"); - goto out; - } - /* Point to the global root filesystem */ - self->fs->root.de = g_root_dentry; - self->fs->root.mnt = g_root_mnt; - self->fs->pwd = self->fs->root; - } - - /* Open /dev/console → fd 0 (stdin), dup to fd 1, 2 */ - { - extern int64 sys_openat(uint64, uint64, uint64, uint64, uint64, uint64); - extern int64 sys_dup(uint64, uint64, uint64, uint64, uint64, uint64); - - int64 fd0 = - sys_openat(static_cast<uint64>(-100), /* AT_FDCWD */ - reinterpret_cast<uint64>("/dev/console"), O_RDWR, 0, 0, 0); - if (fd0 < 0) { - printk(KERN_ERR "[init] open /dev/console failed: %d\n", - static_cast<int>(fd0)); - } else { - sys_dup(static_cast<uint64>(fd0), 0, 0, 0, 0, 0); /* fd 1 */ - sys_dup(static_cast<uint64>(fd0), 0, 0, 0, 0, 0); /* fd 2 */ - printk(KERN_INFO "[init] fd 0/1/2 -> /dev/console\n"); - } - } - - /* - * Try to exec /sbin/init (like Linux kernel_init). - * If not found, fall through to idle. - */ - { - extern int kernel_execve(const char *, const char *const *, - const char *const *); - - const char *init_paths[] = {"/sbin/init", "/etc/init", "/bin/init", - "/bin/sh", nullptr}; - const char *argv[] = {"/sbin/init", nullptr}; - const char *envp[] = {"HOME=/", "PATH=/sbin:/bin", nullptr}; - - for (int i = 0; init_paths[i]; i++) { - argv[0] = init_paths[i]; - int ret = kernel_execve(init_paths[i], argv, envp); - if (ret == 0) { - /* Success — do_execve modified our trapframe. - * When this kthread returns through the trap return path, - * it will jump to user space. */ - return; - } - printk(KERN_INFO "[init] exec %s failed: %d\n", init_paths[i], ret); - } - - printk(KERN_ERR "[init] No init found! Kernel panic.\n"); - } - -out: - extern void task_exit(int code); - task_exit(0); -} - -// ============================================================ -// Second-stage synchronization barrier (C++ layer) -// AP cores spin here until BSP finishes all global init. -// ============================================================ -static lume::atomic<uint32> ap_boot_sync; - -// ============================================================ -// kernel_main — C++ entry point for all CPUs -// ============================================================ -extern "C" [[noreturn]] void kernel_main(uint64 cpu_id, uint64 fdt_paddr) { - - if (cpu_id == bsp_hart_id) { - // ======================================================== - // BSP: Absolute single-core period — no locks needed. - // APs are spinning on ap_boot_sync. - // ======================================================== - - uint64 fdt_pa = fdt_paddr; - - // ---- Phase 1: Console + Exception Safety Net ---- - - // 1. Early console setup: discover UART via FDT before ANY output. - console_early_init(fdt_pa); - klog_init(); - - printk("\n"); - printk(KERN_INFO "LumeOS Kernel v0.1\n"); - printk(KERN_INFO "boot: BSP online, cpu_id=%llu\n", cpu_id); - printk(KERN_INFO "boot: higher-half kernel active\n"); - - /* kernel_map filled by arch/riscv/mm/init.cc::setup_vm before MMU - * enable; relocate_kernel has already applied .rela.dyn. */ - printk(KERN_INFO "boot: kimage phys=0x%llx virt=0x%llx size=%llu\n", - static_cast<unsigned long long>(kernel_map.phys_addr), - static_cast<unsigned long long>(kernel_map.virt_addr), - static_cast<unsigned long long>(kernel_map.size)); - - // --- Subsystem init DAG (strict top-down order) --- - - // 2. Trap handler — install exception vector FIRST. - // Any fault from here on gets a proper panic backtrace - // instead of a silent hang. (Linux: trap_init is in start_kernel - // right after setup_arch.) - trap_init(); - printk(KERN_INFO "init: trap_init done\n"); - - // 3. FDT parsing — make device tree available - fdt_init(fdt_pa); - printk(KERN_INFO "init: fdt_init done\n"); - - // 4. KASLR — seed PRNG and randomise VA layout. - // MUST happen before vmm_init() builds the kernel page table. - { - uint64 kaslr_seed = 0; - fdt_early_get_kaslr_seed(&kaslr_seed); - random_early_init(kaslr_seed); - arch::kaslr_init(); - } - - // Sort exception table before setting RO permissions in vmm_init() - extable_init(); - - // ---- Phase 2: Memory Subsystem (strict cascade) ---- - - // 5. Memblock allocator (Early boot PA allocator) - memblock_init(fdt_pa); - printk(KERN_INFO "init: memblock_init done\n"); - - // 6. Virtual memory manager — builds page table with KASLR'd bases - vmm_init(); - printk(KERN_INFO "init: vmm_init done\n"); - - // 7. Physical memory manager (Buddy) - pmm_init(); - printk(KERN_INFO "init: pmm_init done\n"); - - // 8. Slab allocator — operator new usable after this - slab_init(); - printk(KERN_INFO "init: slab_init done\n"); - - // 9. Page cache (minimal hash table, stable interface for file-backed mmap) - page_cache_init(); - - // 10. FDT Phase 2 — build DeviceNode object tree (needs Slab) - fdt_unflatten(); - printk(KERN_INFO "init: fdt_unflatten done\n"); - - // ---- Phase 3: Task & Scheduler (software state before hardware) ---- - - // 11. Task management (PID allocator + global task list) - task_init(); - printk(KERN_INFO "init: task_init done\n"); - - pgrp_init(); - - sched_init(); - printk(KERN_INFO "init: sched_init done\n"); - - // ---- Phase 3.5: VFS (needs slab + sched) ---- - super_init(); - ramfs_init(); - vfs_init(); - printk(KERN_INFO "init: vfs_init done (ramfs root mounted)\n"); - - // ---- Phase 3.55: Unpack initramfs into root ---- - populate_rootfs(); - - // ---- Phase 3.6: Device nodes ---- - cdev_init(); - console_cdev_init(); - devfs_init(); - printk(KERN_INFO "init: devfs done\n"); - - // ---- Phase 4: Hardware Drivers & Interrupts ---- - - // 13. Hardware Drivers Discovery (Interrupt Controllers, etc) - driver_probe_all(); - printk(KERN_INFO "init: driver_probe_all done\n"); - - // 13.5. TTY subsystem — needs PLIC (driver_probe_all) for UART RX IRQ - tty_init(); - printk(KERN_INFO "init: tty_init done\n"); - - // 14. Timer interrupt (scheduler tick source) - // Safe now: scheduler is fully initialized. - timer_init(); - printk(KERN_INFO "init: timer_init done\n"); - - // 15. Syscall jump table - syscall_init(); - printk(KERN_INFO "init: syscall_init done\n"); - - // 16. SMP / IPI infrastructure - smp_init(); - arch::cpu::software_intr_on(); // Enable S-mode software interrupts for IPI - arch::cpu::external_intr_on(); // Enable S-mode external interrupts for PLIC (UART) - - // ---- Phase 5: Self-test & Launch ---- - - // 17. Boot self-tests — verify subsystem correctness. - // Tests that create kthreads must wait() for them (freeing PIDs). - selftest_run_all(); - - // 18. Spawn PID 1 (init) — the first persistent task. - // Like Linux's rest_init() → user_mode_thread(kernel_init). - // All test PIDs have been freed, so PID 1 is available. - TaskControlBlock *init_task = - kthread_create("init", init_thread_func, nullptr, 0); - if (init_task) { - init_task->flags |= TF_INIT; - - /* Init is session and process-group leader: sid = pgid = pid. - * Allocate signal_struct AND sighand_struct eagerly so every - * descendant (created via task_clone) inherits a real identity - * and a real lock object — signal sending must take siglock and - * cannot tolerate a null sighand. */ - init_task->signal = alloc_signal_struct(init_task->pid, init_task); - if (!init_task->signal) { - printk(KERN_ERR "boot: FAILED to allocate init signal_struct\n"); - } - init_task->sighand = alloc_sighand(); - if (!init_task->sighand) { - printk(KERN_ERR "boot: FAILED to allocate init sighand\n"); - } - - /* Publish g_init_task so reparenting paths can find the foster - * parent when other tasks exit before init takes over user space. */ - extern TaskControlBlock* g_init_task; - g_init_task = init_task; - - printk(KERN_INFO "boot: init thread created (pid=%d sid=%d pgid=%d)\n", - init_task->pid, - init_task->signal ? init_task->signal->sid : -1, - init_task->signal ? init_task->signal->pgid : -1); - } else { - printk(KERN_ERR "boot: FAILED to create init thread!\n"); - } - - - BOOT_STAGE(5, "core kernel init"); - printk(KERN_INFO "boot: BSP init complete, releasing APs\n"); - - // Release APs with RELEASE semantics: - // guarantees all global data is visible to APs. - ap_boot_sync.store(1, __ATOMIC_RELEASE); - - // Start AP harts via SBI HSM extension. - // OpenSBI v1.0+ parks non-boot harts in STOPPED state. - // They must be explicitly started with sbi_hart_start(). - // - // kernel_map.phys_addr was filled by setup_vm in arch/riscv/mm/init.cc - // before MMU enable — it's the runtime PA at which the kernel was - // loaded. APs start at the same PA as the BSP. - { - uint64 start_pa = kernel_map.phys_addr; - if (start_pa == 0) { - /* Defensive fallback if setup_vm hasn't filled the field. */ - start_pa = - boot_va_to_pa(virt_addr(reinterpret_cast<uint64>(_start))).raw; - } - uint32 num_harts = 4; // TODO: read from FDT /cpus - for (uint32 h = 0; h < num_harts; h++) { - if (h == static_cast<uint32>(cpu_id)) - continue; // skip BSP - auto ret = arch::sbi::sbi_hart_start(h, start_pa, fdt_paddr); - if (ret.error == arch::sbi::SBI_SUCCESS) { - printk(KERN_INFO "smp: started hart %u at PA 0x%llx\n", h, start_pa); - } else { - printk(KERN_ERR "smp: failed to start hart %u (err=%ld)\n", h, - ret.error); - } - } - } - - // BSP enables interrupts — first timer tick will preempt - // into the scheduler loop, which will pick up PID 1. - arch::cpu::intr_on(); - - printk(KERN_INFO "boot: BSP entering idle loop\n"); - - } else { - // ======================================================== - // AP: spin until BSP finishes global init - // ======================================================== - // DEBUG (commented out — uncomment for SMP debugging): - // arch::sbi::sbi_ecall(1, 0, '1'); // AP entered kernel_main - - while (ap_boot_sync.load(__ATOMIC_ACQUIRE) == 0) - ; - - // arch::sbi::sbi_ecall(1, 0, '2'); // AP passed ap_boot_sync - - // --- Per-CPU init (must happen before any printk!) --- - // early_pgdir doesn't map UART MMIO, so we MUST switch to - // BSP's kernel page table before any console output. - vmm_init_ap(); // Switch to BSP-built kernel page table - - // arch::sbi::sbi_ecall(1, 0, '3'); // vmm_init_ap done - - trap_init_ap(); // Install stvec on this CPU - - // arch::sbi::sbi_ecall(1, 0, '4'); // trap_init_ap done - - printk(KERN_INFO "boot: AP online, cpu_id=%llu\n", cpu_id); - - sched_init_ap(); // Init per-CPU RunQueue, create Idle Task - - // arch::sbi::sbi_ecall(1, 0, '5'); // sched_init_ap done - - timer_init_ap(); // Start this CPU's timer interrupt - arch::cpu::software_intr_on(); // Enable S-mode software interrupts for IPI - arch::cpu::external_intr_on(); // Enable S-mode external interrupts for PLIC (UART) - - // AP is now a fully functional scheduler CPU. - // Enable interrupts — first timer tick preempts into idle loop. - arch::cpu::intr_on(); - - printk(KERN_INFO "boot: AP cpu_id=%llu fully initialized\n", cpu_id); - } - - // All CPUs reach here. - // The "current task" is the boot stub (bsp_task or ap_task, pid=-1). - // We must hand off to the scheduler's idle task by calling schedule(). - // Without this, the BSP runs as bsp_task (O1 class, timeslice=20 ticks) - // instead of the idle task (which yields immediately when any task is - // runnable). That delays PID 1 by up to 200ms and can stall entirely - // if no timer tick fires before the first WFI. - { - TaskControlBlock *self = current_task(); - if (self) { - self->state = TaskState::Dead; // Boot stub is done; don't re-enqueue - } - schedule(); // Switch to idle task (or init if it's already runnable) - } - - // Should not reach here — schedule() switches away permanently. - // But just in case, spin with WFI as a safety net. - while (true) { - arch::cpu::halt_until_interrupt(); - } -} |