6 files changed, 169 insertions, 38 deletions

diff --git a/src/kernel/init.c b/src/kernel/init.c
index 6bb7eb5..2ba607d 100644
--- a/src/kernel/init.c
+++ b/src/kernel/init.c
@@ -23,6 +23,7 @@
 #include "heap.h"

 #include "task.h"

 #include "vfs.h"

+#include <fs/initrd.h>

 #include <arch/stm/stm32l476xx.h>

 

 extern uint8_t __bss_end__;

@@ -45,6 +46,9 @@ int main(void)
 	heap_init(&__bss_end__);

 	gpio_init();

 

+	vfs_init();

+	initrd_init();

+

 	// enable FPU

 	//SCB->CPACR |= (0xF << 20);

 

diff --git a/src/kernel/svc.c b/src/kernel/svc.c
index 1e03262..f448ee0 100644
--- a/src/kernel/svc.c
+++ b/src/kernel/svc.c
@@ -26,6 +26,7 @@
 extern void gpio_svc(uint32_t *);
 extern void clock_svc(uint32_t *);
 extern void task_svc(uint32_t *);
+extern void vfs_svc(uint32_t *args);
 
 void SVC_Handler(void) {
 	uint32_t *args;
@@ -66,6 +67,12 @@ void SVC_Handler(void) {
 		 */
 		clock_svc(args);
 		break;
+	case 3: /* Filesystem-related calls
+		 * 0 - mount
+		 * 1 - open
+		 */
+		vfs_svc(args);
+		break;
 	default:
 		break;
 	}
diff --git a/src/kernel/task.c b/src/kernel/task.c
index e4531db..2550e4b 100644
--- a/src/kernel/task.c
+++ b/src/kernel/task.c
@@ -30,11 +30,6 @@ static task_t *task_queue;
 static uint8_t task_disable = 0;
 static pid_t task_next_pid = 0;
 
-void task_exit(int code);
-int task_fork(void);
-pid_t task_getpid(void);
-pid_t task_waitpid(pid_t pid, int *wstatus, int options);
-
 void task_svc(uint32_t *args)
 {
 	switch (args[0]) {
diff --git a/src/kernel/task.h b/src/kernel/task.h
index d78e1da..30e3e66 100644
--- a/src/kernel/task.h
+++ b/src/kernel/task.h
@@ -21,7 +21,6 @@
 #ifndef TASK_H_
 #define TASK_H_
 
-#include "vfs.h"
 #include <stdint.h>
 
 #define WIFEXITED(w)   (w & (1 << 8))
@@ -42,7 +41,6 @@ typedef struct task_t {
 		uint32_t state : 8;
 		uint32_t value : 24;
 	} status;
-//	vfs_node *cwd;
 } task_t;
 
 enum TASK_STATUS_FLAGS {
@@ -76,6 +74,13 @@ void task_hold(uint8_t hold);
 
 void task_sleep(uint32_t ms);
 
-//vfs_node *task_getcwd(void);
+void task_exit(int code);
+
+int task_fork(void);
+
+pid_t task_getpid(void);
+
+pid_t task_waitpid(pid_t pid, int *wstatus, int options);
+
 
 #endif // TASK_H_
diff --git a/src/kernel/vfs.c b/src/kernel/vfs.c
index a0d9bb4..1720a6b 100644
--- a/src/kernel/vfs.c
+++ b/src/kernel/vfs.c
@@ -1,15 +1,121 @@
 #include "vfs.h"
-#include "task.h"
 
-//static vfs_node vfs_root;
+#include <kernel/task.h>
 
-int vfs_open(const char *path, int mode)
+#define VFS_MAX_VOLS  8
+#define VFS_MAX_FILES 10
+
+static vfs_volume vfs_volumes[VFS_MAX_VOLS];
+static vfs_file vfs_files[VFS_MAX_FILES];
+
+void vfs_svc(uint32_t *args)
+{
+	switch (args[0]) {
+	case 0:
+		*((int *)args[3]) = vfs_mount((vfs_volume_funcs *)args[1],
+			args[2]);
+		break;
+	case 1:
+		*((int *)args[3]) = vfs_open((const char *)args[1], args[2]);
+		break;
+	case 2:
+		*((int *)args[4]) = vfs_read(args[1], args[2], (uint8_t *)args[3]);
+		break;
+	default:
+		break;
+	}
+}
+
+void vfs_init(void)
+{
+	for (int i = 0; i < VFS_MAX_VOLS; i++)
+		vfs_volumes[i].flags = 0;
+	for (int i = 0; i < VFS_MAX_FILES; i++)
+		vfs_files[i].flags = 0;
+}
+
+int vfs_mount(vfs_volume_funcs *funcs, uint32_t flags)
+{
+	for (int i = 0; i < VFS_MAX_VOLS; i++) {
+		if (!(vfs_volumes[i].flags && VFS_MOUNTED)) {
+			vfs_volumes[i].flags = VFS_MOUNTED | flags;
+			vfs_volumes[i].funcs = funcs;
+			return i;
+		}
+	}
+
+	return -1;
+}
+
+int vfs_get_drive(const char *path)
+{
+	// Validate parameters
+	if (path[0] == '\0' || path[1] == '\0' || path[1] != ':' ||
+		path[2] == '\0' || path[2] != '/')
+		return -1;
+
+	// Find chosen drive
+	int drive = -1;
+	for (int i = 0; i < VFS_MAX_VOLS; i++) {
+		if (path[0] == ('a' + i) || path[0] == ('A' + i)) {
+			drive = i;
+			break;
+		}
+	}
+
+	if (drive == -1 || !(vfs_volumes[drive].flags && VFS_MOUNTED))
+		return -1;
+
+	return drive;
+}
+
+int vfs_open(const char *path, uint32_t flags)
+{
+	int drive = vfs_get_drive(path);
+	if (drive == -1)
+		return -1;
+	if (vfs_volumes[drive].funcs->open == 0)
+		return -1;
+
+	// Find available file handle
+	int file = -1;
+	for (int i = 0; i < VFS_MAX_FILES; i++) {
+		if (!(vfs_files[i].flags & VFS_FILE_OPEN)) {
+			file = i;
+			break;
+		}
+	}
+
+	if (file == -1)
+		return -1;
+
+	vfs_files[file].flags = VFS_FILE_OPEN | flags;
+	vfs_files[file].vol = drive;
+	vfs_files[file].pid = task_getpid();
+	vfs_files[file].fsinfo =
+		vfs_volumes[drive].funcs->open(path + 3);
+
+	return file;
+}
+
+uint32_t vfs_read(int fd, uint32_t count, uint8_t *buffer)
 {
-	(void)path;
-	(void)mode;
-//	vfs_node *cd = task_getcwd();
-//	if (cd == 0)
-//		cd = &vfs_root;
+	if (fd < 0 || fd > VFS_MAX_FILES || count == 0 || buffer == 0)
+		return 0;
+	if (vfs_volumes[vfs_files[fd].vol].funcs->read == 0)
+		return -1;
+	if (vfs_files[fd].pid != task_getpid())
+		return 0;
+	if ((!(vfs_files[fd].flags & VFS_FILE_READ)) || (vfs_files[fd].flags &
+		VFS_EOF))
+		return 0;
 
-	return 0;
+	uint32_t ret = vfs_volumes[vfs_files[fd].vol].funcs->read(vfs_files[fd].fsinfo,
+		count, buffer);
+
+	if (ret < count)
+		vfs_files[fd].flags |= VFS_EOF;
+
+	return ret;
 }
+
diff --git a/src/kernel/vfs.h b/src/kernel/vfs.h
index 6874905..a6de690 100644
--- a/src/kernel/vfs.h
+++ b/src/kernel/vfs.h
@@ -3,30 +3,44 @@
 
 #include <stdint.h>
 
-struct vfs_node;
-struct dirent;
+typedef struct {
+	char name[32];
+} vfs_dirent;
+
+typedef struct {
+	void *(*open)(const char *file);
+	void (*close)(void *info);
+	uint32_t (*read)(void *info, uint32_t count, uint8_t *buffer);
+	uint32_t (*write)(void *info, uint32_t count, const uint8_t *buffer);
+	vfs_dirent *(*readdir)(const char *path);
+} vfs_volume_funcs;
+
+#define VFS_MOUNTED  (1 << 0)
+#define VFS_READONLY (1 << 1)
 
 typedef struct {
-	uint32_t (*read)(struct vfs_node *, uint32_t, uint32_t, uint8_t *);
-	uint32_t (*write)(struct vfs_node *, uint32_t, uint32_t, const uint8_t *);
-	void (*open)(struct vfs_node *);
-	void (*close)(struct vfs_node *);
-} vfs_driver;
-
-typedef struct vfs_node {
-	char *name;
 	uint32_t flags;
+	vfs_volume_funcs *funcs;
+} vfs_volume;
+
+#define VFS_FILE_OPEN  (1 << 0)
+#define VFS_FILE_READ  (1 << 1)
+#define VFS_FILE_WRITE (1 << 2)
+#define VFS_FILE_MODF  (1 << 3)
+#define VFS_TEMPORARY  (1 << 4)
+#define VFS_EOF        (1 << 5)
+
+typedef struct {
+	uint32_t flags;
+	uint32_t vol;
+	uint32_t pid;
+	void *fsinfo;
+} vfs_file;
+
+void vfs_init(void);
 
-	struct vfs_node *parent;
-	union {
-		struct vfs_node* children;
-		vfs_driver *access;
-	} data;
-} vfs_node;
-
-struct dirent {
-	char *name;
-	vfs_node *node;
-};
+int vfs_mount(vfs_volume_funcs *funcs, uint32_t flags);
+int vfs_open(const char *path, uint32_t flags);
+uint32_t vfs_read(int fd, uint32_t count, uint8_t *buffer);
 
 #endif // VFS_H_