kernel: some random modifications

kernel/src/fs/vfs.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <stdint.h>
+
+struct vfs {
+  struct vfs *vfs_next;           /* next vfs in list */
+  struct vfsops *vfs_op;          /* operations on vfs */
+  struct vnode *vfs_vnodecovered; /* vnode we cover */
+  int vfs_flag;                   /* flags */
+  int vfs_bsize;                  /* native block size */
+  uint64_t vfs_data;               /* private data */
+};
+
+struct vfsops {
+  int (*vfs_mount)();
+  int (*vfs_unmount)();
+  int (*vfs_root)();
+  int (*vfs_statfs)();
+  int (*vfs_sync)();
+  int (*vfs_fid)();
+  int (*vfs_vget)();
+};
+
+enum vtype { VNON, VREG, VDIR, VBLK, VCHR, VLNK, VSOCK, VBAD };
+struct vnode {
+  uint16_t v_flag;               /* vnode flags */
+  uint16_t v_count;              /* reference count */
+  uint16_t v_shlockc;            /* # of shared locks */
+  uint16_t v_exlockc;            /* # of exclusive locks */
+  struct vfs *v_vfsmountedhere; /* covering vfs */
+  struct vnodeops *v_op;        /* vnode operations */
+  union {
+    struct socket *v_Socket; /* unix ipc */
+    struct stdata *v_Stream; /* stream */
+  };
+  struct vfs *v_vfsp; /* vfs we are in */
+  enum vtype v_type;  /* vnode type */
+  uint64_t v_data;     /* private data */
+};
+
+struct vnodeops {
+  int (*vn_open)();
+  int (*vn_close)();
+  int (*vn_rdwr)();
+  int (*vn_ioctl)();
+  int (*vn_select)();
+  int (*vn_getattr)();
+  int (*vn_setattr)();
+  int (*vn_access)();
+  int (*vn_lookup)();
+  int (*vn_create)();
+  int (*vn_remove)();
+  int (*vn_link)();
+  int (*vn_rename)();
+  int (*vn_mkdir)();
+  int (*vn_rmdir)();
+  int (*vn_readdir)();
+  int (*vn_symlink)();
+  int (*vn_readlink)();
+  int (*vn_fsync)();
+  int (*vn_inactive)();
+  int (*vn_bmap)();
+  int (*vn_strategy)();
+  int (*vn_bread)();
+  int (*vn_brelse)();
+};

kernel/src/main.c

@@ -80,9 +80,9 @@ char kstack[8192];
 // linker script accordingly.
 void kmain(void) {
     // Ensure the bootloader actually understands our base revision (see spec).
-    if (LIMINE_BASE_REVISION_SUPPORTED == false) {
+    /*if (LIMINE_BASE_REVISION_SUPPORTED == false) {
         hcf();
-    }
+    }*/
 
     // Ensure we got a framebuffer.
     if (framebuffer_request.response == NULL
@@ -118,11 +118,13 @@ void kmain(void) {
     uint8_t *mem = pmm_request_page();
     mem[0] = 0xCD;
     mem[1] = 0x80;
-    mem[2] = 0xF4;
+    //mem[2] = 0xF4;
+
     //mem[3] = 0xFE;
     pagemap_t* pm = vmm_alloc_pm();
     vmm_map(pm, 0x1000, (uint64_t)mem, VMM_PRESENT | VMM_USER);
-    sched_process *proc = sched_create("Init", 0x1000, pm, SCHED_USER_PROCESS);
+    sched_create("Init", 0x1000, pm, SCHED_USER_PROCESS);
+
 
     log("kernel - Soaplin initialized sucessfully.\n");
     while (1)

kernel/src/rt.c

@@ -53,7 +53,7 @@ void rt_print(char *str) {
 
     for (int i = 0; i < _rt_strlen(str); i++) {
         if (str[i] == '\n' && _curctx.use_crlf_ending)
-            if (_curctx.y * 16 >= _curctx.framebuffer_height) {
+            if (_curctx.y * 16 >= (int)_curctx.framebuffer_height) {
                 _curctx.y = 0;
                 memset(
                     _curctx.framebuffer, _curctx.bg_color,
@@ -63,7 +63,7 @@ void rt_print(char *str) {
             }
         else if (str[i] == '\n')
         {
-            if (_curctx.y * 16 >= _curctx.framebuffer_height) {
+            if (_curctx.y * 16 >= (int)_curctx.framebuffer_height) {
                 _curctx.y = 0;
                 memset(
                     _curctx.framebuffer, _curctx.bg_color,

kernel/src/sched/sched.c

@@ -56,10 +56,12 @@ sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t* pm, uin
 
     if (flags == SCHED_KERNEL_PROCESS) {
         proc->stack_base = stack_phys;
+        proc->stack_base_physical = stack_phys;
         proc->stack_end = proc_list->stack_base + PMM_PAGE_SIZE;
     } else if (flags == SCHED_USER_PROCESS) {
         vmm_map(proc->pm, (uint64_t)stack_virt, (uint64_t)stack_phys, VMM_PRESENT | VMM_WRITABLE | VMM_USER);
         proc->stack_base = stack_virt;
+        proc->stack_base_physical = stack_phys;
         proc->stack_end = proc_list->stack_base + PMM_PAGE_SIZE;
     }
     proc->regs.rip = (uint64_t)entry_point;
@@ -91,6 +93,12 @@ sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t* pm, uin
     return proc;
 }
 
+void sched_exit(int exit_code) {
+    log("sched - Process %d exited with code %d!", curr_proc->pid, exit_code);
+    curr_proc->type = SCHED_DIED;
+    schedule(&curr_proc->regs);
+}
+
 void schedule(registers_t *regs)
 {
     if (standby) {
@@ -98,6 +106,22 @@ void schedule(registers_t *regs)
         return;
     }
 
+    if (curr_proc->type == SCHED_DIED) {
+        sched_process *prev_proc = proc_list;
+        while (prev_proc->next != curr_proc) {
+            prev_proc = prev_proc->next;
+        }
+
+        prev_proc->next = curr_proc->next;
+
+        // Now, it is safe to free the process's memory.
+        vmm_release_pm(curr_proc->pm);
+        pmm_free_page(curr_proc->stack_base_physical);
+
+        // R.I.P. process
+        pmm_free_page(curr_proc);
+    }
+
     memcpy(&curr_proc->regs, regs, sizeof(registers_t));
 
     curr_proc = curr_proc->next;

kernel/src/sched/sched.h

@@ -8,7 +8,7 @@
 
 typedef enum {
     SCHED_RUNNING,
-    SCHED_EXITED,
+    SCHED_DIED,
     SCHED_EMPTY
 } sched_proc_type;
 
@@ -23,6 +23,7 @@ typedef struct _sched_process {
 
     uint64_t *stack_end;
     uint64_t *stack_base;
+    uint64_t *stack_base_physical;
 
     struct _sched_process *next;
 } sched_process;
@@ -36,5 +37,5 @@ extern sched_process *proc_list;
 
 void sched_init();
 sched_process *sched_create(char *name, uint64_t entry_point, pagemap_t *pm, uint32_t flags);
-void sched_exit(sched_process *proc);
+void sched_exit(int exit_code);
 void schedule(registers_t *regs);

kernel/src/sys/arch/x86_64/interrupts.c

@@ -73,7 +73,8 @@ void exception_handler(registers_t *regs) {
     {
         log("syscall - Hello World! Current process: %s\n", curr_proc->name);
         if (curr_proc->flags == SCHED_USER_PROCESS)
-        log("syscall - Btw we made it to userspace, baby!\n", curr_proc->name);
+            log("syscall - Btw we made it to userspace, baby!\n", curr_proc->name);
+    
     }
     //logln(info, "arch/ints", "Received interrupt %d\n", regs->int_no);
     pic_ack(regs->int_no - 32);

kernel/src/sys/arch/x86_64/rtc.c

@@ -21,5 +21,6 @@ void rtc_init() {
 }
 
 void rtc_handle_interrupt(registers_t *regs) {
+    (void)regs;
     printf("RTC!\n");
 }

kernel/src/sys/arch/x86_64/smp.c

@@ -0,0 +1,6 @@
+#include "sys/arch/x86_64/smp.h"
+#include "limine.h"
+
+void smp_init() {
+
+}

kernel/src/sys/arch/x86_64/smp.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void smp_init();

kernel/src/sys/log.c

@@ -16,14 +16,14 @@ void log(char *format, ...) {
     rt_print(buf);
 
     char *date = "1970-01-01 00:00:00 | ";
-    for (int i;;i++) {
+    for (int i=0;;i++) {
         if (date[i] == '\0')
             break;
         
         outb(0xE9, date[i]);
     }
 
-    for (int i;;i++) {
+    for (int i=0;;i++) {
         if (buf[i] == '\0')
             break;