From 0d1c8a1bdb47b2782ed8df003deaaef9ae7cebf3 Mon Sep 17 00:00:00 2001
From: Mark <alnyan@airmail.cc>
Date: Fri, 25 Oct 2019 11:46:56 +0300
Subject: [PATCH] Add tarfs/initrd support

---
 include/sys/dev.h     |  3 ++-
 sys/amd64/kernel.c    |  7 +++++++
 sys/amd64/sys/sched.c | 18 ++++++++++++++++++
 sys/blk/ram.c         | 15 +++++++++++++++
 sys/dev.c             |  8 ++++++++
 sys/vfs/vfs.c         |  1 -
 6 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/include/sys/dev.h b/include/sys/dev.h
index 6d04919..b209ab1 100644
--- a/include/sys/dev.h
+++ b/include/sys/dev.h
@@ -8,7 +8,8 @@ enum dev_class {
 
 #define DEV_BLOCK_SDx       1
 #define DEV_BLOCK_HDx       2
-#define DEV_BLOCK_PART      3
+#define DEV_BLOCK_RAM       3
+#define DEV_BLOCK_PART      127
 
 struct dev_entry {
     char dev_name[64];
diff --git a/sys/amd64/kernel.c b/sys/amd64/kernel.c
index 7590a7b..dbaa216 100644
--- a/sys/amd64/kernel.c
+++ b/sys/amd64/kernel.c
@@ -14,6 +14,8 @@
 #include "sys/panic.h"
 #include "sys/assert.h"
 #include "sys/fs/vfs.h"
+#include "sys/blk/ram.h"
+#include "sys/fs/tar.h"
 
 static multiboot_info_t *multiboot_info;
 
@@ -39,6 +41,11 @@ void kernel_main(struct amd64_loader_data *data) {
     pci_init();
 
     vfs_init();
+    if (data->initrd_ptr) {
+        // Create ram0 block device
+        ramblk_init(MM_VIRTUALIZE(data->initrd_ptr), data->initrd_len);
+        tarfs_init();
+    }
 
 #if defined(AMD64_SMP)
     amd64_smp_init();
diff --git a/sys/amd64/sys/sched.c b/sys/amd64/sys/sched.c
index 62a041f..ca76477 100644
--- a/sys/amd64/sys/sched.c
+++ b/sys/amd64/sys/sched.c
@@ -4,6 +4,11 @@
 #include "sys/debug.h"
 #include "sys/heap.h"
 #include "sys/spin.h"
+#include "sys/fs/vfs.h"
+#include "sys/fs/fcntl.h"
+#include "sys/errno.h"
+#include "sys/blk.h"
+#include "sys/panic.h"
 
 static struct thread *sched_queue_heads[AMD64_MAX_SMP] = { 0 };
 static struct thread *sched_queue_tails[AMD64_MAX_SMP] = { 0 };
@@ -28,6 +33,19 @@ void idle_func(uintptr_t id) {
 
 void init_func(void *arg) {
     kdebug("Entering [init]\n");
+
+    // Mount rootfs if available
+    struct blkdev *root_blk = blk_by_name("ram0");
+    struct vfs_ioctx ioctx = {0};
+    struct ofile fd;
+    int res;
+
+    if (root_blk) {
+        if ((res = vfs_mount(&ioctx, "/", root_blk, "ustar", NULL)) != 0) {
+            panic("mount rootfs: %s\n", kstrerror(res));
+        }
+    }
+
     while (1) {
         asm volatile ("sti; hlt");
     }
diff --git a/sys/blk/ram.c b/sys/blk/ram.c
index a801a7c..ff11315 100644
--- a/sys/blk/ram.c
+++ b/sys/blk/ram.c
@@ -1,5 +1,8 @@
 #include "sys/blk/ram.h"
 #include "sys/string.h"
+#include "sys/assert.h"
+#include "sys/heap.h"
+#include "sys/dev.h"
 
 #define MIN(x, y) ((x) < (y) ? (x) : (y))
 
@@ -28,4 +31,16 @@ struct blkdev *ramblk0 = &_ramblk0;
 void ramblk_init(uintptr_t at, size_t len) {
     ram_priv.begin = at;
     ram_priv.lim = len;
+
+    struct dev_entry *ent = (struct dev_entry *) kmalloc(sizeof(struct dev_entry));
+    _assert(ent);
+
+    ent->dev = ramblk0;
+    ent->dev_class = DEV_CLASS_BLOCK;
+    ent->dev_subclass = DEV_BLOCK_RAM;
+    if (dev_alloc_name(ent->dev_class, ent->dev_subclass, ent->dev_name) != 0) {
+        panic("Failed to allocate a name for ram device\n");
+    }
+
+    dev_entry_add(ent);
 }
diff --git a/sys/dev.c b/sys/dev.c
index bb13c9a..e4bde30 100644
--- a/sys/dev.c
+++ b/sys/dev.c
@@ -3,14 +3,22 @@
 #include "sys/assert.h"
 #include "sys/panic.h"
 #include "sys/debug.h"
+#include "sys/string.h"
 
 static struct dev_entry *dev_begin = NULL;
 static struct dev_entry *dev_end = NULL;
 
 static uint64_t dev_scsi_bitmap = 0;
 static uint64_t dev_ide_bitmap = 0;
+static int dev_ram_count = 0;
 
 static int dev_alloc_block_name(uint16_t subclass, char *name) {
+    if (subclass == DEV_BLOCK_RAM) {
+        strcpy(name, "ram");
+        name[3] = dev_ram_count++ + '0';
+        name[4] = 0;
+        return 0;
+    }
     if (subclass == DEV_BLOCK_SDx || subclass == DEV_BLOCK_HDx) {
         uint64_t *bmp = subclass == DEV_BLOCK_SDx ? &dev_scsi_bitmap : &dev_ide_bitmap;
         name[1] = 'd';
diff --git a/sys/vfs/vfs.c b/sys/vfs/vfs.c
index f7bdcdb..581eb1d 100644
--- a/sys/vfs/vfs.c
+++ b/sys/vfs/vfs.c
@@ -424,7 +424,6 @@ static int vfs_mount_internal(struct vfs_node *at, void *blkdev, const char *fs_
         panic("Trying to mount a filesystem at a destination which already is a mount\n");
     }
 
-
     if (fs->cls->opt & FS_NODE_MAPPER) {
         _assert(fs_class->mapper);
         // Request the driver to map VFS tree for us