feat: add remaining console.obj functions (closes #1)

Cargo.toml

@@ -21,3 +21,6 @@ path = "examples/dark.rs"
 [profile.release]
 opt-level = "z"
 lto = "thin"
+
+[[example]]
+name = "fs_demo"

examples/fs_demo.rs

@@ -0,0 +1,12 @@
+#![no_std]
+#![no_main]
+
+use kos::fs::fs_read;
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    let path = c"/rd/1/readme.txt";
+    let mut buf = [0u8; 512];
+    let (_status, _bytes) = fs_read(path, &mut buf);
+    loop {}
+}

src/fs.rs

@@ -0,0 +1,14 @@
+use core::ffi::CStr;
+use crate::sys::{syscall_fs, FileSystemRequest};
+
+pub fn fs_read(path: &CStr, buf: &mut [u8]) -> (u32, u32) {
+    let req = FileSystemRequest {
+        operation:   0,
+        offset_low:  0,
+        offset_high: 0,
+        byte_count:  buf.len() as u32,
+        buffer:      buf.as_mut_ptr() as u32,
+        path:        path.as_ptr() as u32,
+    };
+    unsafe { syscall_fs(&req) }
+}

src/lib.rs

@@ -6,6 +6,7 @@ mod nanolibc;
 pub mod allocation;
 pub mod dll;
 pub mod sys;
+pub mod fs;
 
 pub use modules::*;
 

src/sys.rs

@@ -68,3 +68,26 @@ extern "C" {
     #[link_name = "_load_dll"]
     pub fn load_dll(name: *const u8) -> *const u32;
 }
+
+#[repr(C)]
+pub struct FileSystemRequest {
+    pub operation:    u32,
+    pub offset_low:   u32,
+    pub offset_high:  u32,
+    pub byte_count:   u32,
+    pub buffer:       u32,
+    pub path:         u32,
+}
+
+pub unsafe fn syscall_fs(req: *const FileSystemRequest) -> (u32, u32) {
+    let eax_result: u32;
+    let ebx_result: u32;
+    core::arch::asm!(
+        "int 0x40",
+        inout("eax") 70u32 => eax_result,
+        in("ebx") req,
+        out("ebx") ebx_result,
+        options(nostack)
+    );
+    (eax_result, ebx_result)
+}