From ff468db6754acbc455bcc14fe991716655433863 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sat, 11 Mar 2023 10:34:08 +0100
Subject: [PATCH] kernel/ELF+Scheduler: Use VFS instead of TarStream

---
 kernel/src/ELF.cpp              | 16 ++++++++--------
 kernel/src/ELF.h                |  4 ++--
 kernel/src/main.cpp             | 13 ++-----------
 kernel/src/thread/Scheduler.cpp |  4 ++--
 kernel/src/thread/Scheduler.h   |  4 ++--
 5 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/kernel/src/ELF.cpp b/kernel/src/ELF.cpp
index 1af55e15..955706ea 100644
--- a/kernel/src/ELF.cpp
+++ b/kernel/src/ELF.cpp
@@ -26,13 +26,14 @@ static bool can_write_segment(u32 flags)
 namespace ELFLoader
 {
     // FIXME: Check that all calls to read_contents() read the proper amount of bytes.
-    Result<ELFData> load(const TarStream::Entry& elf_entry, const TarStream& stream)
+    Result<ELFData> load(SharedPtr<VFS::Inode> inode)
     {
         Elf64_Ehdr elf_header;
-        usize nread = stream.read_contents(elf_entry, &elf_header, 0, sizeof elf_header);
+        usize nread = TRY(inode->read((u8*)&elf_header, 0, sizeof elf_header));
+
         if (nread < sizeof elf_header)
         {
-            kdbgln("Error while loading ELF: ELF header does not fit in entry");
+            kdbgln("Error while loading ELF: ELF header does not fit in file");
             return err(ENOEXEC);
         }
 
@@ -78,10 +79,10 @@ namespace ELFLoader
         usize i;
         Elf64_Phdr program_header;
 
-        for (stream.read_contents(elf_entry, &program_header, elf_header.e_phoff, sizeof program_header), i = 0;
+        for (TRY(inode->read((u8*)&program_header, elf_header.e_phoff, sizeof program_header)), i = 0;
              i < elf_header.e_phnum;
-             i++, stream.read_contents(elf_entry, &program_header, elf_header.e_phoff + (i * elf_header.e_phentsize),
-                                       sizeof program_header))
+             i++, TRY(inode->read((u8*)&program_header, elf_header.e_phoff + (i * elf_header.e_phentsize),
+                                  sizeof program_header)))
         {
             if (program_header.p_type == PT_LOAD)
             {
@@ -103,8 +104,7 @@ namespace ELFLoader
                     base_vaddr, get_blocks_from_size(program_header.p_memsz + vaddr_diff, ARCH_PAGE_SIZE), flags));
 
                 // Load the file section of the segment
-                stream.read_contents(elf_entry, (void*)program_header.p_vaddr, program_header.p_offset,
-                                     program_header.p_filesz);
+                inode->read((u8*)program_header.p_vaddr, program_header.p_offset, program_header.p_filesz);
 
                 // Fill out the rest of the segment with 0s
                 memset((void*)(program_header.p_vaddr + program_header.p_filesz), 0,
diff --git a/kernel/src/ELF.h b/kernel/src/ELF.h
index 440bae4b..d5217c48 100644
--- a/kernel/src/ELF.h
+++ b/kernel/src/ELF.h
@@ -1,6 +1,6 @@
 #pragma once
+#include "fs/VFS.h"
 #include <luna/LinkedList.h>
-#include <luna/TarStream.h>
 #include <luna/Types.h>
 
 #define ELFMAG "\177ELF"
@@ -54,5 +54,5 @@ struct ELFData
 
 namespace ELFLoader
 {
-    Result<ELFData> load(const TarStream::Entry& elf_entry, const TarStream& stream);
+    Result<ELFData> load(SharedPtr<VFS::Inode> inode);
 };
diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp
index eceebffd..6688076a 100644
--- a/kernel/src/main.cpp
+++ b/kernel/src/main.cpp
@@ -63,18 +63,9 @@ static void init_vfs()
 
 static Result<void> try_init_userspace()
 {
-    TarStream::Entry entry;
-    g_initrd.rewind();
-    while (TRY(g_initrd.read_next_entry(entry)))
-    {
-        if (entry.type == TarStream::EntryType::RegularFile)
-        {
-            kinfoln("Found file %s in initial ramdisk, of size %s and mode %#ho", entry.name,
-                    to_dynamic_unit(entry.size).release_value().chars(), entry.mode);
+    auto app = TRY(VFS::resolve_path("/bin/app"));
 
-            if (!strcmp(entry.name, "bin/app")) { TRY(Scheduler::new_userspace_thread(entry, g_initrd)); }
-        }
-    }
+    TRY(Scheduler::new_userspace_thread(app));
 
     return {};
 }
diff --git a/kernel/src/thread/Scheduler.cpp b/kernel/src/thread/Scheduler.cpp
index 286e1674..0f1eb7cb 100644
--- a/kernel/src/thread/Scheduler.cpp
+++ b/kernel/src/thread/Scheduler.cpp
@@ -118,7 +118,7 @@ namespace Scheduler
         return {};
     }
 
-    Result<void> new_userspace_thread(const TarStream::Entry& entry, const TarStream& stream)
+    Result<void> new_userspace_thread(SharedPtr<VFS::Inode> inode)
     {
         Thread* const thread = TRY(new_thread());
 
@@ -139,7 +139,7 @@ namespace Scheduler
 
         thread->init_regs_user();
 
-        const ELFData data = TRY(ELFLoader::load(entry, stream));
+        const ELFData data = TRY(ELFLoader::load(inode));
 
         thread->set_ip(data.entry);
 
diff --git a/kernel/src/thread/Scheduler.h b/kernel/src/thread/Scheduler.h
index c2dd4cfc..fecee620 100644
--- a/kernel/src/thread/Scheduler.h
+++ b/kernel/src/thread/Scheduler.h
@@ -1,6 +1,6 @@
 #pragma once
+#include "fs/VFS.h"
 #include "thread/Thread.h"
-#include <luna/TarStream.h>
 
 namespace Scheduler
 {
@@ -13,7 +13,7 @@ namespace Scheduler
     Result<void> new_kernel_thread(void (*func)(void));
     Result<void> new_kernel_thread(void (*func)(void*), void* arg);
 
-    Result<void> new_userspace_thread(const TarStream::Entry& entry, const TarStream& stream);
+    Result<void> new_userspace_thread(SharedPtr<VFS::Inode> inode);
 
     Thread* pick_task();