Added spinlocks

src/bootloader/main.s

@@ -21,13 +21,16 @@ bits 16
 ;Load part2                                 |x|
 ;Get video mode information                 |0|
 ;Set video mode                             |0|
-;get memory map                             |0|
-;enable paging                              |0|
-;read filesystem                            |0|
-;load kernel                                |0|
-;parse ELF format                           |0|
-;pass memory and video information to kernel|0|
-;relocate and jump to kernel                |0|
+;get memory map                             |x|
+;enable paging                              |x|
+;read filesystem                            |x|
+;load kernel                                |x|
+;parse ELF format                           |x|
+;pass memory and video information to kernel|x|
+;relocate and jump to kernel                |x|
+
+;TODO 7/4/26
+;Remember to ZERO THE BSS
 
 jump:
     jmp short start

src/kernel/drivers/serial.c

@@ -83,6 +83,10 @@ void vprintf(char *string, va_list vars){
                     num = va_arg(vars, int32_t);
                     printf((char[]){num, 0});
                     continue;
+                case 'b':
+                    string++;
+                    num = va_arg(vars, int32_t);
+                    printf(num ? "true" : "false");
             }
         }
         outb(com_ports[0], *string);

src/kernel/kmain.c

@@ -57,7 +57,7 @@ extern void kmain(kernel_info_t *kernel_info){
     pic_init(0x20);
     pic_setmask(0x0, PIC1_DATA);
     pic_setmask(0x0, PIC2_DATA);
-    
+    vfs_init();
     fcreate("/dev", FS_FILE_IS_DIR);
     fcreate("/dev/disk", FS_FILE_IS_DIR);
     fcreate("/tmp", FS_FILE_IS_DIR);

src/kernel/shared/kstdlib.h

@@ -4,6 +4,12 @@
 #include "../drivers/serial.h"
 #include "interrupts.h"
 
+#define true 1
+#define false 0
+
+#define null 0
+
+
 #define MLOG_DEBUG 1
 #define MLOG_PRINT 2
 #define MLOG_WARN 3

src/kernel/shared/spinlock.h

@@ -0,0 +1,13 @@
+#include <stdatomic.h>
+
+typedef struct spinlock{
+    atomic_flag lock;
+}spinlock_t;
+
+inline void spinlock_acquire(spinlock_t spinlock){
+    // atomic_compare_exchange_strong(&spinlock.lock, &spinlock.unlocked, spinlock.locked);
+    while(atomic_flag_test_and_set_explicit(&spinlock.lock, memory_order_acquire));
+}
+inline void spinlock_release(spinlock_t spinlock){
+    atomic_flag_clear_explicit(&spinlock.lock, memory_order_release);
+}

src/kernel/system/ramfs.c

@@ -3,7 +3,7 @@
 #include "../shared/kstdlib.h"
 #include "../shared/memory.h"
 #include "../shared/string.h"
-#define MODULE_NAME "KVFS"
+#define MODULE_NAME "RAMFS"
 
 fileops_t ramfs_ops = 
 {
@@ -21,16 +21,22 @@ vfile_t root_dir = {"/", FS_FILE_IS_DIR | FS_FILE_SYSTEM, &ramfs_ops};
 void ramfs_init(){
     mlog(MODULE_NAME, "Initializing VFS\n", MLOG_PRINT);
     root_dir.private = kmalloc(1);
-    root_dir.size = PAGE_SIZE_BYTES;//one page is 4096 bytes
+    root_dir.size = PAGE_SIZE_BYTES;
     // printf("Sizeof VFILE_T: %d", sizeof(vfile_t));
 }
 
 vfile_t *search_dir(char *subname, vfile_t *directory){
-    
+    vfile_t **children = (vfile_t **)directory->private;
+    for(int i = 0; i < directory->size / sizeof(vfile_t *); i++){
+        if(!strcmp(children[i], subname)){
+            return children[i];
+        }
+    }
+    return 0;
 }
 
 //resolves the path relative to start
-vfile_t *resolve_path(char *pathname, vfile_t *start){
+vfile_t *resolve_path(char *pathname, vfile_t *start, uint32_t get_last_child){
     const uint32_t MAX_TOKENS = PAGE_SIZE_BYTES/4;
     
     if(!start){
@@ -57,19 +63,52 @@ vfile_t *resolve_path(char *pathname, vfile_t *start){
         path_tokens[pathname_entries++] = pathtok;
     }
     
-    vfile_t **buffer = (vfile_t **)start->private;
-    printf("START\n");
+    // vfile_t **buffer = (vfile_t **)start->private;
     vfile_t *entry = start;
-    for(int i = 0; i < pathname_entries - 1; i++){
-        printf("%s", path_tokens[i]);
+    char *current_path = pathname;
+    for(int i = 0; i < pathname_entries - !get_last_child; i++){
+        entry = search_dir(path_tokens[i], entry);
+        current_path += strlen(path_tokens[i]) + 1;
         
+        if(!entry){
+            break;
+        }
+        if(entry->flags & FS_FILE_MOUNT){
+            if(!get_last_child){
+                entry = 0;
+                break;
+            }
+            entry->fileops->rfopen(current_path, entry);
+        }
     }
-    printf("END\n");
+    kfree(path);
+    kfree(path_tokens);
+    return entry;
 }
 
+char *get_filename(char *path){
+    char *filename = path + strlen(path) - 1;//get last character in pathname
+    while(*filename != '/' || filename == path) filename--;
+    filename += filename != path;//if the new filename is at the beginning of the path, don't adjust for '/' character
+    return filename;
+}
+
+void ramfs_resize(vfile_t *file, uint32_t new_size_bytes){
+    if(new_size_bytes == file->size) return;
+    uint32_t new_size_pages = (new_size_bytes + PAGE_SIZE_BYTES - 1)/PAGE_SIZE_BYTES;
+    printf("New page count: %d from %d\n", new_size_pages, new_size_bytes);
+}
 
 vfile_t *ramfs_create(char *path, FS_FILE_FLAGS flags){
-    resolve_path("test/test1/test2", &root_dir);
+    if(!path){
+        return 0;
+    }
+    vfile_t *parent = resolve_path(path, &root_dir, false);
+    if(!parent){
+        mlog(MODULE_NAME, "Could not locate parent directory for %s\n", MLOG_PRINT, path);
+    }
+    get_filename(path);
+    ramfs_resize(parent, 8191);
     return 0;
 }
 

src/kernel/system/vfs.c

@@ -3,6 +3,7 @@
 #include "../shared/kstdlib.h"
 #include "../shared/memory.h"
 #include "../shared/string.h"
+#include "../shared/spinlock.h"
 #define MODULE_NAME "KVFS"
 
 // !TODO: Modify code to become thread-safe
@@ -13,9 +14,17 @@
 //     return;
 // }
 
+spinlock_t vfs_lock;
+
+void vfs_init(){
+    spinlock_release(vfs_lock);
+}
+
 vfile_t *fcreate(char *path, FS_FILE_FLAGS flags){
     // return 0;
+    spinlock_acquire(vfs_lock);
     vfile_t *returnable = vfcreate(get_root_dir(), path, flags);
+    spinlock_release(vfs_lock);
     return 0;
 }
 
@@ -60,9 +69,11 @@ vfile_t *vfcreate(vfile_t *parent_dir, char *relpath, FS_FILE_FLAGS flags){
 }
 
 int fdelete(vfile_t *file_entry){
+    spinlock_acquire(vfs_lock);
     if(!file_entry || !file_entry->fileops || !file_entry->fileops->delete){
         return 0;
     }
+    spinlock_release(vfs_lock);
     return file_entry->fileops->delete(file_entry);
 }
 

src/kernel/system/vfs.h

@@ -37,6 +37,8 @@ typedef struct virtual_file{
     
 }vfile_t;
 
+void vfs_init();
+
 // vfile_t *rfopen(char *name, vfile_t dir);
 vfile_t *fcreate(char *path, FS_FILE_FLAGS flags);
 int fdelete(vfile_t* file_entry);

src/kmodules/disk_driver.c

@@ -379,7 +379,8 @@ int ata_read(vfile_t *file, uint8_t *ptr, uint32_t offset, uint32_t count) {
     transferring_pid = cpid;
     
     outb(bm_base, 0x09); 
-    asm("sti");
+    // asm("sti"); // TODO: Make it so that instead of sti(), restore interrupt flag
+    if(!api(MODULE_API_IS_INTERRUPT)) asm("sti");
     
     uint8_t status = inb(ctrl_base);
     uint8_t bm_status = inb(bm_base + 2);