feat: lseek(2), read(2), write(2) implementation

[lunaix-os.git] / lunaix-os / kernel / k_init.c

diff --git a/lunaix-os/kernel/k_init.c b/lunaix-os/kernel/k_init.c
index bbd505d488b6c8123c25e98b983f1340ec79fd26..ffc287ff37bb840d7bb2f8ecc8ff7368a7ab9211 100644 (file)
--- a/lunaix-os/kernel/k_init.c
+++ b/lunaix-os/kernel/k_init.c
@@ -1,23 +1,19 @@
 #include <lunaix/common.h>
 #include <lunaix/tty/tty.h>
 
 #include <lunaix/common.h>
 #include <lunaix/tty/tty.h>
 

+#include <lunaix/clock.h>
+#include <lunaix/lxconsole.h>
+#include <lunaix/mm/kalloc.h>

 #include <lunaix/mm/page.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/vmm.h>
 #include <lunaix/mm/page.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/vmm.h>

-#include <lunaix/mm/kalloc.h>
+#include <lunaix/process.h>
+#include <lunaix/sched.h>

 #include <lunaix/spike.h>
 #include <lunaix/syslog.h>
 #include <lunaix/timer.h>
 #include <lunaix/spike.h>
 #include <lunaix/syslog.h>
 #include <lunaix/timer.h>

-#include <lunaix/clock.h>
-#include <lunaix/peripheral/ps2kbd.h>
-#include <lunaix/process.h>
-#include <lunaix/sched.h>
-#include <lunaix/syscall.h>

 
 #include <hal/rtc.h>
 
 #include <hal/rtc.h>

-#include <hal/apic.h>
-#include <hal/ioapic.h>
-#include <hal/acpi/acpi.h>

 
 #include <arch/x86/boot/multiboot.h>
 #include <arch/x86/idt.h>
 
 #include <arch/x86/boot/multiboot.h>
 #include <arch/x86/idt.h>


@@ -26,9 +22,8 @@
 #include <klibc/stdio.h>
 #include <klibc/string.h>
 
 #include <klibc/stdio.h>
 #include <klibc/string.h>
 

-#include <stdint.h>

 #include <stddef.h>
 #include <stddef.h>

-
+#include <stdint.h>

 
 extern uint8_t __kernel_start;
 extern uint8_t __kernel_end;
 
 extern uint8_t __kernel_start;
 extern uint8_t __kernel_end;


@@ -39,20 +34,24 @@ extern uint8_t __init_hhk_end;
 // Set remotely by kernel/asm/x86/prologue.S
 multiboot_info_t* _k_init_mb_info;
 
 // Set remotely by kernel/asm/x86/prologue.S
 multiboot_info_t* _k_init_mb_info;
 

+x86_page_table* __kernel_ptd;
+
+struct proc_info tmp;
+

 LOG_MODULE("BOOT");
 
 LOG_MODULE("BOOT");
 

-extern void _lxinit_main();
-void spawn_lxinit();
-void _kernel_post_init();
+extern void
+__proc0(); /* proc0.c */

 
 void
 
 void

-setup_memory(multiboot_memory_map_t* map, size_t map_size);
+spawn_proc0();

 
 void
 
 void

-lock_reserved_memory();
+setup_memory(multiboot_memory_map_t* map, size_t map_size);

 
 void
 
 void

-_kernel_pre_init() {
+_kernel_pre_init()
+{

     _init_idt();
     intr_routine_init();
 
     _init_idt();
     intr_routine_init();
 


@@ -60,169 +59,158 @@ _kernel_pre_init() {
     vmm_init();
     rtc_init();
 
     vmm_init();
     rtc_init();
 

-    tty_init((void*)VGA_BUFFER_PADDR);
+    unsigned int map_size =
+      _k_init_mb_info->mmap_length / sizeof(multiboot_memory_map_t);
+
+    setup_memory((multiboot_memory_map_t*)_k_init_mb_info->mmap_addr, map_size);
+
+    tty_init((void*)VGA_BUFFER_VADDR);

     tty_set_theme(VGA_COLOR_WHITE, VGA_COLOR_BLACK);
     tty_set_theme(VGA_COLOR_WHITE, VGA_COLOR_BLACK);

+
+    __kernel_ptd = cpu_rcr3();
+
+    tmp = (struct proc_info){ .page_table = __kernel_ptd };
+
+    __current = &tmp;

 }
 
 void
 }
 
 void

-_kernel_init() {
-    kprintf("[MM] Mem: %d KiB, Extended Mem: %d KiB\n",
-           _k_init_mb_info->mem_lower,
-           _k_init_mb_info->mem_upper);
+_kernel_init()
+{
+    lxconsole_init();

 
 

-    unsigned int map_size = _k_init_mb_info->mmap_length / sizeof(multiboot_memory_map_t);
-    
-    setup_memory((multiboot_memory_map_t*)_k_init_mb_info->mmap_addr, map_size);
+    cake_init();
+    valloc_init();

 
 

-    // 为内核创建一个专属栈空间。
-    for (size_t i = 0; i < (KSTACK_SIZE >> PG_SIZE_BITS); i++) {
-        vmm_alloc_page(KERNEL_PID, (void*)(KSTACK_START + (i << PG_SIZE_BITS)), NULL, PG_PREM_RW, 0);
-    }
-    kprintf(KINFO "[MM] Allocated %d pages for stack start at %p\n", KSTACK_SIZE>>PG_SIZE_BITS, KSTACK_START);
+    kprintf(KINFO "[MM] Allocated %d pages for stack start at %p\n",
+            KSTACK_SIZE >> PG_SIZE_BITS,
+            KSTACK_START);

 
     sched_init();
 
 
     sched_init();
 

-    spawn_lxinit();
+    spawn_proc0();

 }
 
 /**
 }
 
 /**

- * @brief 创建并运行init进程
- * 
+ * @brief 创建并运行proc0进程
+ *

  */
  */

-void spawn_lxinit() {
-    struct proc_info kinit;
-    uint32_t* kstack = (uint32_t*)KSTACK_TOP - 4 * 5;
-
-    memset(&kinit, 0, sizeof(kinit));
-    kinit.page_table = (void*) cpu_rcr3();
-    kinit.parent = -1;
-    kinit.pid = 1;
-    kinit.intr_ctx = (isr_param) {
-        .registers.esp = kstack,
-        .cs = KCODE_SEG,
-        .eip = (void*)_kernel_post_init,
-        .ss = KDATA_SEG,
-        .eflags = cpu_reflags()
-    };
-
-    /* 
-        因为schedule从设计上是需要在中断环境中执行的
-        可是我们需要在这里手动调用 schedule，从而使我们的init能够被执行。
-        所以需要模拟中断产生时的栈里内容。
-    */ 
-    kstack[2] = kinit.intr_ctx.eip;
-    kstack[3] = kinit.intr_ctx.cs;
-    kstack[4] = kinit.intr_ctx.eflags;
-
-    push_process(&kinit);
-    
-    schedule();
-}
-
-void 
-_kernel_post_init() {
-    assert_msg(kalloc_init(), "Fail to initialize heap");
-    
-    size_t hhk_init_pg_count = ((uintptr_t)(&__init_hhk_end)) >> PG_SIZE_BITS;
-    kprintf(KINFO "[MM] Releaseing %d pages from 0x0.\n", hhk_init_pg_count);
-
-    // Fuck it, I will no longer bother this little 1MiB
-    // I just release 4 pages for my APIC & IOAPIC remappings
-    for (size_t i = 0; i < 3; i++) {
-        vmm_unmap_page(KERNEL_PID, (void*)(i << PG_SIZE_BITS));
-    }
-    
-    // 锁定所有系统预留页（内存映射IO，ACPI之类的），并且进行1:1映射
-    lock_reserved_memory();
-
-    acpi_init(_k_init_mb_info);
-    uintptr_t ioapic_addr = acpi_get_context()->madt.ioapic->ioapic_addr;
-    pmm_mark_page_occupied(KERNEL_PID, FLOOR(__APIC_BASE_PADDR, PG_SIZE_BITS), 0);
-    pmm_mark_page_occupied(KERNEL_PID, FLOOR(ioapic_addr, PG_SIZE_BITS), 0);
-
-    vmm_set_mapping(KERNEL_PID, APIC_BASE_VADDR, __APIC_BASE_PADDR, PG_PREM_RW);
-    vmm_set_mapping(KERNEL_PID, IOAPIC_BASE_VADDR, ioapic_addr, PG_PREM_RW);
-
-    apic_init();
-    ioapic_init();
-    timer_init(SYS_TIMER_FREQUENCY_HZ);
-    clock_init();
-    ps2_kbd_init();
-
-    syscall_install();
+void
+spawn_proc0()
+{
+    struct proc_info* proc0 = alloc_process();
+
+    /**
+     * @brief
+     * 注意：这里和视频中说的不一样，属于我之后的一点微调。
+     * 在视频中，spawn_proc0是在_kernel_post_init的末尾才调用的。并且是直接跳转到_proc0
+     *
+     * 但是我后来发现，上述的方法会产生竞态条件。这是因为spawn_proc0被调用的时候，时钟中断已经开启，
+     * 而中断的产生会打乱栈的布局，从而使得下面的上下文设置代码产生未定义行为（Undefined
+     * Behaviour）。 为了保险起见，有两种办法：
+     *      1. 在创建proc0进程前关闭中断
+     *      2. 将_kernel_post_init搬进proc0进程
+     * （_kernel_post_init已经更名为init_platform）
+     *
+     * 目前的解决方案是2
+     */
+
+    proc0->intr_ctx = (isr_param){ .registers = { .ds = KDATA_SEG,
+                                                  .es = KDATA_SEG,
+                                                  .fs = KDATA_SEG,
+                                                  .gs = KDATA_SEG },
+                                   .cs = KCODE_SEG,
+                                   .eip = (void*)__proc0,
+                                   .ss = KDATA_SEG,
+                                   .eflags = cpu_reflags() };
+    proc0->parent = proc0;
+
+    // 方案1：必须在读取eflags之后禁用。否则当进程被调度时，中断依然是关闭的！
+    // cpu_disable_interrupt();
+
+    /* Ok... 首先fork进我们的零号进程，而后由那里，我们fork进init进程。 */
+
+    // 把当前虚拟地址空间（内核）复制一份。
+    proc0->page_table = vmm_dup_vmspace(proc0->pid);
+
+    // 直接切换到新的拷贝，进行配置。
+    cpu_lcr3(proc0->page_table);

 
 

-    for (size_t i = 256; i < hhk_init_pg_count; i++) {
-        vmm_unmap_page(KERNEL_PID, (void*)(i << PG_SIZE_BITS));
+    // 为内核创建一个专属栈空间。
+    for (size_t i = 0; i < (KSTACK_SIZE >> PG_SIZE_BITS); i++) {
+        uintptr_t pa = pmm_alloc_page(KERNEL_PID, 0);
+        vmm_set_mapping(PD_REFERENCED,
+                        KSTACK_START + (i << PG_SIZE_BITS),
+                        pa,
+                        PG_PREM_RW,
+                        VMAP_NULL);

     }
 
     }
 

-    _lxinit_main();
-
-    spin();
+    // 手动设置进程上下文：用于第一次调度
+    asm volatile("movl %%esp, %%ebx\n"
+                 "movl %1, %%esp\n"
+                 "pushf\n"
+                 "pushl %2\n"
+                 "pushl %3\n"
+                 "pushl $0\n"
+                 "pushl $0\n"
+                 "movl %%esp, %0\n"
+                 "movl %%ebx, %%esp\n"
+                 : "=m"(proc0->intr_ctx.registers.esp)
+                 : "i"(KSTACK_TOP), "i"(KCODE_SEG), "r"(proc0->intr_ctx.eip)
+                 : "%ebx", "memory");
+
+    // 向调度器注册进程。
+    commit_process(proc0);
+
+    // 由于时钟中断与APIC未就绪，我们需要手动进行第一次调度。这里也会同时隐式地恢复我们的eflags.IF位
+    proc0->state = PS_RUNNING;
+    asm volatile("pushl %0\n"
+                 "jmp switch_to\n" ::"r"(proc0));
+
+    /* Should not return */
+    assert_msg(0, "Unexpected Return");

 }
 
 }
 

-void
-lock_reserved_memory() {
-    multiboot_memory_map_t* mmaps = _k_init_mb_info->mmap_addr;
-    size_t map_size = _k_init_mb_info->mmap_length / sizeof(multiboot_memory_map_t);
-    for (unsigned int i = 0; i < map_size; i++) {
-        multiboot_memory_map_t mmap = mmaps[i];
-        if (mmap.type == MULTIBOOT_MEMORY_AVAILABLE) {
-            continue;
-        }
-        uint8_t* pa = PG_ALIGN(mmap.addr_low);
-        size_t pg_num = CEIL(mmap.len_low, PG_SIZE_BITS);
-        for (size_t j = 0; j < pg_num; j++)
-        {
-            vmm_set_mapping(KERNEL_PID, (pa + (j << PG_SIZE_BITS)), (pa + (j << PG_SIZE_BITS)), PG_PREM_R);
-        }
-    }
-}
+extern void __usrtext_start;
+extern void __usrtext_end;

 
 // 按照 Memory map 标识可用的物理页
 void
 
 // 按照 Memory map 标识可用的物理页
 void

-setup_memory(multiboot_memory_map_t* map, size_t map_size) {
+setup_memory(multiboot_memory_map_t* map, size_t map_size)
+{

 
     // First pass, to mark the physical pages
     for (unsigned int i = 0; i < map_size; i++) {
         multiboot_memory_map_t mmap = map[i];
 
     // First pass, to mark the physical pages
     for (unsigned int i = 0; i < map_size; i++) {
         multiboot_memory_map_t mmap = map[i];

-        kprintf("[MM] Base: 0x%x, len: %u KiB, type: %u\n",
-               map[i].addr_low,
-               map[i].len_low >> 10,
-               map[i].type);

         if (mmap.type == MULTIBOOT_MEMORY_AVAILABLE) {
             // 整数向上取整除法
             uintptr_t pg = map[i].addr_low + 0x0fffU;
         if (mmap.type == MULTIBOOT_MEMORY_AVAILABLE) {
             // 整数向上取整除法
             uintptr_t pg = map[i].addr_low + 0x0fffU;

-            pmm_mark_chunk_free(pg >> PG_SIZE_BITS, map[i].len_low >> PG_SIZE_BITS);
-            kprintf(KINFO "[MM] Freed %u pages start from 0x%x\n",
-                   map[i].len_low >> PG_SIZE_BITS,
-                   pg & ~0x0fffU);
+            pmm_mark_chunk_free(pg >> PG_SIZE_BITS,
+                                map[i].len_low >> PG_SIZE_BITS);

         }
     }
 
     // 将内核占据的页，包括前1MB，hhk_init 设为已占用
     size_t pg_count = V2P(&__kernel_end) >> PG_SIZE_BITS;
     pmm_mark_chunk_occupied(KERNEL_PID, 0, pg_count, 0);
         }
     }
 
     // 将内核占据的页，包括前1MB，hhk_init 设为已占用
     size_t pg_count = V2P(&__kernel_end) >> PG_SIZE_BITS;
     pmm_mark_chunk_occupied(KERNEL_PID, 0, pg_count, 0);

-    kprintf(KINFO "[MM] Allocated %d pages for kernel.\n", pg_count);
-

 
     size_t vga_buf_pgs = VGA_BUFFER_SIZE >> PG_SIZE_BITS;
 
     size_t vga_buf_pgs = VGA_BUFFER_SIZE >> PG_SIZE_BITS;

-    
-    // 首先，标记VGA部分为已占用
-    pmm_mark_chunk_occupied(KERNEL_PID, VGA_BUFFER_PADDR >> PG_SIZE_BITS, vga_buf_pgs, 0);
-    
+
+    // 首先，标记VGA部分为已占用，并且锁定
+    pmm_mark_chunk_occupied(
+      KERNEL_PID, VGA_BUFFER_PADDR >> PG_SIZE_BITS, vga_buf_pgs, PP_FGLOCKED);
+

     // 重映射VGA文本缓冲区（以后会变成显存，i.e., framebuffer）
     // 重映射VGA文本缓冲区（以后会变成显存，i.e., framebuffer）

-    for (size_t i = 0; i < vga_buf_pgs; i++)
-    {
-        vmm_map_page(
-            KERNEL_PID,
-            (void*)(VGA_BUFFER_VADDR + (i << PG_SIZE_BITS)), 
-            (void*)(VGA_BUFFER_PADDR + (i << PG_SIZE_BITS)), 
-            PG_PREM_RW
-        );
+    for (size_t i = 0; i < vga_buf_pgs; i++) {
+        vmm_set_mapping(PD_REFERENCED,
+                        VGA_BUFFER_VADDR + (i << PG_SIZE_BITS),
+                        VGA_BUFFER_PADDR + (i << PG_SIZE_BITS),
+                        PG_PREM_URW,
+                        VMAP_NULL);

     }
     }

-    
-    // 更新VGA缓冲区位置至虚拟地址
-    tty_set_buffer((void*)VGA_BUFFER_VADDR);

 
 

-    kprintf(KINFO "[MM] Mapped VGA to %p.\n", VGA_BUFFER_VADDR);
-}
\ No newline at end of file
+    for (uintptr_t i = &__usrtext_start; i < &__usrtext_end; i += PG_SIZE) {
+        vmm_set_mapping(PD_REFERENCED, i, V2P(i), PG_PREM_UR, VMAP_NULL);
+    }
+}