Tried to implement kernel in rust

rust/kernel/.cargo/config.toml

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+[unstable]
+json-target-spec = true
+build-std = ["core", "compiler_builtins"]
+build-std-features = ["compiler-builtins-mem"]
+
+[build]
+target = "target.json"
+
+[target.'cfg(target_os = "none")']
+runner = "bootimage runner"

rust/kernel/.gitignore

@@ -0,0 +1 @@
+target/*

rust/kernel/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "bootloader"
+version = "0.9.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13f6a8a495d2f93fe3d6eb3a224f9aa749a63cfd746ed03eb5ddcbd00ade7d8f"
+
+[[package]]
+name = "deros-kernel"
+version = "0.1.0"
+dependencies = [
+ "bootloader",
+]

rust/kernel/Cargo.toml

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+[package]
+name = "deros-kernel"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+bootloader = "0.9"
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+
+
+[[bin]]
+name = "deros-kernel"
+test = false
+bench = false

rust/kernel/linker.ld

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+/* The bootloader will look at this image and start execution at the symbol
+   designated as the entry point. */
+ENTRY(_start)
+
+/* Tell where the various sections of the object files will be put in the final
+   kernel image. */
+SECTIONS
+{
+	/* It used to be universally recommended to use 1M as a start offset,
+	   as it was effectively guaranteed to be available under BIOS systems.
+	   However, UEFI has made things more complicated, and experimental data
+	   strongly suggests that 2M is a safer place to load. In 2016, a new
+	   feature was introduced to the multiboot2 spec to inform bootloaders
+	   that a kernel can be loaded anywhere within a range of addresses and
+	   will be able to relocate itself to run from such a loader-selected
+	   address, in order to give the loader freedom in selecting a span of
+	   memory which is verified to be available by the firmware, in order to
+	   work around this issue. This does not use that feature, so 2M was
+	   chosen as a safer option than the traditional 1M. */
+	. = 2M;
+
+	/* First put the multiboot header, as it is required to be put very early
+	   in the image or the bootloader won't recognize the file format.
+	   Next we'll put the .text section. */
+	.text ALIGN(4K) : ALIGN(4K)
+	{
+		*(.multiboot)
+		*(.text)
+	}
+
+	/* Read-only data. */
+	.rodata ALIGN(4K) : ALIGN(4K)
+	{
+		*(.rodata)
+	}
+
+	/* Read-write data (initialized) */
+	.data ALIGN(4K) : ALIGN(4K)
+	{
+		*(.data)
+	}
+
+	/* Read-write data (uninitialized) and stack */
+	.bss ALIGN(4K) : ALIGN(4K)
+	{
+		*(COMMON)
+		*(.bss)
+	}
+
+	/* The compiler may produce other sections, by default it will put them in
+	   a segment with the same name. Simply add stuff here as needed. */
+}

rust/kernel/src/main.rs

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+#![no_std]
+#![no_main]
+
+static HELLO: &[u8] = b"Hello World!";
+
+#[unsafe(no_mangle)]
+fn _start() -> ! {
+    let vga_buffer = 0xb8000 as *mut u8;
+    for (i, &byte) in HELLO.iter().enumerate() {
+        unsafe {
+            *vga_buffer.offset(i as isize * 2) = byte;
+            *vga_buffer.offset(i as isize * 2 + 1) = 0xb;
+        }
+    }
+    loop {}
+}
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    loop {}
+}

rust/kernel/target.json

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+{
+  "llvm-target": "x86_64-unknown-none",
+  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+  "arch": "x86_64",
+  "target-endian": "little",
+  "target-pointer-width": 64,
+  "target-c-int-width": 32,
+  "os": "none",
+  "executables": true,
+  "linker-flavor": "ld.lld",
+  "linker": "rust-lld",
+  "panic-strategy": "abort",
+  "disable-redzone": true,
+  "features": "-mmx,-sse,+soft-float",
+  "dynamic-linking": false,
+  "relocation-model": "pic",
+  "code-model": "kernel",
+  "exe-suffix": ".elf",
+  "has-rpath": false,
+  "no-default-libraries": true,
+  "position-independent-executables": false,
+  "pre-link-args": {
+    "ld.lld": [
+      "--script=./linker.ld"
+    ]
+  },
+  "rustc-abi": "x86-softfloat"
+}