Add code for tutorial 04
Andre Richter
5 years ago
parent
dd4a132259
commit
a851959f89
@ -0,0 +1,41 @@
|
||||
# This file is automatically @generated by Cargo.
|
||||
# It is not intended for manual editing.
|
||||
[[package]]
|
||||
name = "cortex-a"
|
||||
version = "2.7.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
dependencies = [
|
||||
"register 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "kernel"
|
||||
version = "0.1.0"
|
||||
dependencies = [
|
||||
"cortex-a 2.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
|
||||
"r0 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "r0"
|
||||
version = "0.2.2"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
|
||||
[[package]]
|
||||
name = "register"
|
||||
version = "0.3.3"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
dependencies = [
|
||||
"tock-registers 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
|
||||
]
|
||||
|
||||
[[package]]
|
||||
name = "tock-registers"
|
||||
version = "0.3.0"
|
||||
source = "registry+https://github.com/rust-lang/crates.io-index"
|
||||
|
||||
[metadata]
|
||||
"checksum cortex-a 2.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cbb16c411ab74044f174746a6cbae67bcdebea126e376b5441e5986e6a6aa950"
|
||||
"checksum r0 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e2a38df5b15c8d5c7e8654189744d8e396bddc18ad48041a500ce52d6948941f"
|
||||
"checksum register 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "469bb5ddde81d67fb8bba4e14d77689b8166cfd077abe7530591cefe29d05823"
|
||||
"checksum tock-registers 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c758f5195a2e0df9d9fecf6f506506b2766ff74cf64db1e995c87e2761a5c3e2"
|
||||
@ -0,0 +1,17 @@
|
||||
[package]
|
||||
name = "kernel"
|
||||
version = "0.1.0"
|
||||
authors = ["Andre Richter <andre.o.richter@gmail.com>"]
|
||||
edition = "2018"
|
||||
|
||||
[package.metadata.cargo-xbuild]
|
||||
sysroot_path = "../xbuild_sysroot"
|
||||
|
||||
# The features section is used to select the target board.
|
||||
[features]
|
||||
default = []
|
||||
bsp_rpi3 = []
|
||||
|
||||
[dependencies]
|
||||
r0 = "0.2.2"
|
||||
cortex-a = "2.7.0"
|
||||
@ -0,0 +1,76 @@
|
||||
## SPDX-License-Identifier: MIT
|
||||
##
|
||||
## Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
# Default to the RPi3
|
||||
ifndef BSP
|
||||
BSP = bsp_rpi3
|
||||
endif
|
||||
|
||||
# BSP-specific arguments
|
||||
ifeq ($(BSP),bsp_rpi3)
|
||||
TARGET = aarch64-unknown-none
|
||||
OUTPUT = kernel8.img
|
||||
QEMU_BINARY = qemu-system-aarch64
|
||||
QEMU_MACHINE_TYPE = raspi3
|
||||
QEMU_MISC_ARGS = -serial null -serial stdio
|
||||
LINKER_FILE = src/bsp/rpi3/link.ld
|
||||
RUSTC_MISC_ARGS = -C target-feature=-fp-armv8 -C target-cpu=cortex-a53
|
||||
endif
|
||||
|
||||
SOURCES = $(wildcard **/*.rs) $(wildcard **/*.S) $(wildcard **/*.ld)
|
||||
|
||||
XRUSTC_CMD = cargo xrustc \
|
||||
--target=$(TARGET) \
|
||||
--features $(BSP) \
|
||||
--release \
|
||||
-- \
|
||||
-C link-arg=-T$(LINKER_FILE) \
|
||||
$(RUSTC_MISC_ARGS)
|
||||
|
||||
CARGO_OUTPUT = target/$(TARGET)/release/kernel
|
||||
|
||||
OBJCOPY_CMD = cargo objcopy \
|
||||
-- \
|
||||
--strip-all \
|
||||
-O binary
|
||||
|
||||
CONTAINER_UTILS = rustembedded/osdev-utils
|
||||
|
||||
DOCKER_CMD = docker run -it --rm
|
||||
DOCKER_ARG_CURDIR = -v $(shell pwd):/work -w /work
|
||||
DOCKER_EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE) -kernel $(OUTPUT)
|
||||
|
||||
.PHONY: all qemu clippy clean readelf objdump nm
|
||||
|
||||
all: clean $(OUTPUT)
|
||||
|
||||
$(CARGO_OUTPUT): $(SOURCES)
|
||||
RUSTFLAGS="-D warnings -D missing_docs" $(XRUSTC_CMD)
|
||||
|
||||
$(OUTPUT): $(CARGO_OUTPUT)
|
||||
cp $< .
|
||||
$(OBJCOPY_CMD) $< $(OUTPUT)
|
||||
|
||||
doc:
|
||||
cargo xdoc --target=$(TARGET) --features $(BSP) --document-private-items
|
||||
xdg-open target/$(TARGET)/doc/kernel/index.html
|
||||
|
||||
qemu: all
|
||||
$(DOCKER_CMD) $(DOCKER_ARG_CURDIR) $(CONTAINER_UTILS) \
|
||||
$(DOCKER_EXEC_QEMU) $(QEMU_MISC_ARGS)
|
||||
|
||||
clippy:
|
||||
cargo xclippy --target=$(TARGET) --features $(BSP)
|
||||
|
||||
clean:
|
||||
cargo clean
|
||||
|
||||
readelf:
|
||||
readelf -a kernel
|
||||
|
||||
objdump:
|
||||
cargo objdump --target $(TARGET) -- -disassemble -print-imm-hex kernel
|
||||
|
||||
nm:
|
||||
cargo nm --target $(TARGET) -- kernel | sort
|
||||
@ -0,0 +1,147 @@
|
||||
# Tutorial 04 - Zero Overhead Abstraction
|
||||
|
||||
## tl;dr
|
||||
|
||||
All hand-written assembly is replaced by Rust code from the [cortex-a] crate,
|
||||
which provides zero-overhead abstractions and wraps the `unsafe` parts.
|
||||
|
||||
[cortex-a]: https://github.com/rust-embedded/cortex-a
|
||||
|
||||
## Diff to previous
|
||||
```diff
|
||||
|
||||
diff -uNr 03_hacky_hello_world/Cargo.toml 04_zero_overhead_abstraction/Cargo.toml
|
||||
--- 03_hacky_hello_world/Cargo.toml 2019-09-25 14:41:51.089487788 +0200
|
||||
+++ 04_zero_overhead_abstraction/Cargo.toml 2019-09-25 13:59:33.588482692 +0200
|
||||
@@ -14,3 +14,4 @@
|
||||
|
||||
[dependencies]
|
||||
r0 = "0.2.2"
|
||||
+cortex-a = "2.7.0"
|
||||
|
||||
diff -uNr 03_hacky_hello_world/src/bsp/rpi3/panic_wait.rs 04_zero_overhead_abstraction/src/bsp/rpi3/panic_wait.rs
|
||||
--- 03_hacky_hello_world/src/bsp/rpi3/panic_wait.rs 2019-09-25 14:41:51.093487759 +0200
|
||||
+++ 04_zero_overhead_abstraction/src/bsp/rpi3/panic_wait.rs 2019-09-25 15:26:48.988205284 +0200
|
||||
@@ -6,6 +6,7 @@
|
||||
|
||||
use crate::println;
|
||||
use core::panic::PanicInfo;
|
||||
+use cortex_a::asm;
|
||||
|
||||
#[panic_handler]
|
||||
fn panic(info: &PanicInfo) -> ! {
|
||||
@@ -15,9 +16,7 @@
|
||||
println!("Kernel panic!");
|
||||
}
|
||||
|
||||
- unsafe {
|
||||
- loop {
|
||||
- asm!("wfe" :::: "volatile")
|
||||
- }
|
||||
+ loop {
|
||||
+ asm::wfe();
|
||||
}
|
||||
}
|
||||
|
||||
diff -uNr 03_hacky_hello_world/src/bsp/rpi3/start.S 04_zero_overhead_abstraction/src/bsp/rpi3/start.S
|
||||
--- 03_hacky_hello_world/src/bsp/rpi3/start.S 2019-09-25 15:07:28.593140386 +0200
|
||||
+++ 04_zero_overhead_abstraction/src/bsp/rpi3/start.S 1970-01-01 01:00:00.000000000 +0100
|
||||
@@ -1,21 +0,0 @@
|
||||
-// SPDX-License-Identifier: MIT
|
||||
-//
|
||||
-// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
-
|
||||
-.section ".text._start"
|
||||
-
|
||||
-.global _start
|
||||
-
|
||||
-_start:
|
||||
- mrs x1, mpidr_el1 // Read Multiprocessor Affinity Register
|
||||
- and x1, x1, #3 // Clear all bits except [1:0], which hold core id
|
||||
- cbz x1, 2f // Jump to label 2 if we are core 0
|
||||
-1: wfe // Wait for event
|
||||
- b 1b // In case an event happend, jump back to 1
|
||||
-2: // If we are here, we are core0
|
||||
- ldr x1, =_start // Load address of function "_start()"
|
||||
- mov sp, x1 // Set start of stack to before our code, aka first
|
||||
- // address before "_start()"
|
||||
- bl init // Jump to the "init()" kernel function
|
||||
- b 1b // We should never reach here. But just in case,
|
||||
- // park this core aswell
|
||||
|
||||
diff -uNr 03_hacky_hello_world/src/bsp/rpi3.rs 04_zero_overhead_abstraction/src/bsp/rpi3.rs
|
||||
--- 03_hacky_hello_world/src/bsp/rpi3.rs 2019-09-25 14:41:51.093487759 +0200
|
||||
+++ 04_zero_overhead_abstraction/src/bsp/rpi3.rs 2019-09-25 15:19:14.474175689 +0200
|
||||
@@ -8,8 +8,34 @@
|
||||
|
||||
use crate::interface::console;
|
||||
use core::fmt;
|
||||
+use cortex_a::{asm, regs::*};
|
||||
|
||||
-global_asm!(include_str!("rpi3/start.S"));
|
||||
+/// The entry of the `kernel` binary.
|
||||
+///
|
||||
+/// The function must be named `_start`, because the linker is looking for this
|
||||
+/// exact name.
|
||||
+///
|
||||
+/// # Safety
|
||||
+///
|
||||
+/// - Linker script must ensure to place this function at `0x80_000`.
|
||||
+#[no_mangle]
|
||||
+pub unsafe extern "C" fn _start() -> ! {
|
||||
+ use crate::runtime_init;
|
||||
+
|
||||
+ const CORE_0: u64 = 0;
|
||||
+ const CORE_MASK: u64 = 0x3;
|
||||
+ const STACK_START: u64 = 0x80_000;
|
||||
+
|
||||
+ if CORE_0 == MPIDR_EL1.get() & CORE_MASK {
|
||||
+ SP.set(STACK_START);
|
||||
+ runtime_init::init()
|
||||
+ } else {
|
||||
+ // if not core0, infinitely wait for events
|
||||
+ loop {
|
||||
+ asm::wfe();
|
||||
+ }
|
||||
+ }
|
||||
+}
|
||||
|
||||
/// A mystical, magical device for generating QEMU output out of the void.
|
||||
struct QEMUOutput;
|
||||
|
||||
diff -uNr 03_hacky_hello_world/src/main.rs 04_zero_overhead_abstraction/src/main.rs
|
||||
--- 03_hacky_hello_world/src/main.rs 2019-09-25 14:41:52.341478676 +0200
|
||||
+++ 04_zero_overhead_abstraction/src/main.rs 2019-09-25 15:22:45.433268740 +0200
|
||||
@@ -13,9 +13,7 @@
|
||||
//!
|
||||
//! [`kernel::interface`]: interface/index.html
|
||||
|
||||
-#![feature(asm)]
|
||||
#![feature(format_args_nl)]
|
||||
-#![feature(global_asm)]
|
||||
#![feature(panic_info_message)]
|
||||
#![no_main]
|
||||
#![no_std]
|
||||
@@ -33,7 +31,7 @@
|
||||
|
||||
/// Entrypoint of the `kernel`.
|
||||
fn kernel_entry() -> ! {
|
||||
- println!("Hello from Rust!");
|
||||
+ println!("Hello from pure Rust!");
|
||||
|
||||
panic!("Stopping here.")
|
||||
}
|
||||
|
||||
diff -uNr 03_hacky_hello_world/src/runtime_init.rs 04_zero_overhead_abstraction/src/runtime_init.rs
|
||||
--- 03_hacky_hello_world/src/runtime_init.rs 2019-09-25 14:41:51.093487759 +0200
|
||||
+++ 04_zero_overhead_abstraction/src/runtime_init.rs 2019-09-25 14:00:32.560262587 +0200
|
||||
@@ -13,7 +13,7 @@
|
||||
///
|
||||
/// - Only a single core must be active and running this function.
|
||||
#[no_mangle]
|
||||
-pub unsafe extern "C" fn init() -> ! {
|
||||
+pub unsafe fn init() -> ! {
|
||||
extern "C" {
|
||||
// Boundaries of the .bss section, provided by the linker script
|
||||
static mut __bss_start: u64;
|
||||
```
|
||||
Binary file not shown.
Binary file not shown.
@ -0,0 +1,11 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! Conditional exporting of Board Support Packages.
|
||||
|
||||
#[cfg(feature = "bsp_rpi3")]
|
||||
pub mod rpi3;
|
||||
|
||||
#[cfg(feature = "bsp_rpi3")]
|
||||
pub use rpi3::*;
|
||||
@ -0,0 +1,69 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! Board Support Package for the Raspberry Pi 3.
|
||||
|
||||
mod panic_wait;
|
||||
|
||||
use crate::interface::console;
|
||||
use core::fmt;
|
||||
use cortex_a::{asm, regs::*};
|
||||
|
||||
/// The entry of the `kernel` binary.
|
||||
///
|
||||
/// The function must be named `_start`, because the linker is looking for this
|
||||
/// exact name.
|
||||
///
|
||||
/// # Safety
|
||||
///
|
||||
/// - Linker script must ensure to place this function at `0x80_000`.
|
||||
#[no_mangle]
|
||||
pub unsafe extern "C" fn _start() -> ! {
|
||||
use crate::runtime_init;
|
||||
|
||||
const CORE_0: u64 = 0;
|
||||
const CORE_MASK: u64 = 0x3;
|
||||
const STACK_START: u64 = 0x80_000;
|
||||
|
||||
if CORE_0 == MPIDR_EL1.get() & CORE_MASK {
|
||||
SP.set(STACK_START);
|
||||
runtime_init::init()
|
||||
} else {
|
||||
// if not core0, infinitely wait for events
|
||||
loop {
|
||||
asm::wfe();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// A mystical, magical device for generating QEMU output out of the void.
|
||||
struct QEMUOutput;
|
||||
|
||||
/// Implementing `console::Write` enables usage of the `format_args!` macros,
|
||||
/// which in turn are used to implement the `kernel`'s `print!` and `println!`
|
||||
/// macros.
|
||||
///
|
||||
/// See [`src/print.rs`].
|
||||
///
|
||||
/// [`src/print.rs`]: ../../print/index.html
|
||||
impl console::Write for QEMUOutput {
|
||||
fn write_str(&mut self, s: &str) -> fmt::Result {
|
||||
for c in s.chars() {
|
||||
unsafe {
|
||||
core::ptr::write_volatile(0x3F21_5040 as *mut u8, c as u8);
|
||||
}
|
||||
}
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
// Implementation of the kernel's BSP calls
|
||||
////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
/// Returns a ready-to-use `console::Write` implementation.
|
||||
pub fn console() -> impl console::Write {
|
||||
QEMUOutput {}
|
||||
}
|
||||
@ -0,0 +1,35 @@
|
||||
/* SPDX-License-Identifier: MIT
|
||||
*
|
||||
* Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
*/
|
||||
|
||||
SECTIONS
|
||||
{
|
||||
/* Set current address to the value from which the RPi3 starts execution */
|
||||
. = 0x80000;
|
||||
|
||||
.text :
|
||||
{
|
||||
*(.text._start) *(.text*)
|
||||
}
|
||||
|
||||
.rodata :
|
||||
{
|
||||
*(.rodata*)
|
||||
}
|
||||
|
||||
.data :
|
||||
{
|
||||
*(.data*)
|
||||
}
|
||||
|
||||
/* Align to 8 byte boundary */
|
||||
.bss ALIGN(8):
|
||||
{
|
||||
__bss_start = .;
|
||||
*(.bss*);
|
||||
__bss_end = .;
|
||||
}
|
||||
|
||||
/DISCARD/ : { *(.comment*) }
|
||||
}
|
||||
@ -0,0 +1,22 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! A panic handler that infinitely waits.
|
||||
|
||||
use crate::println;
|
||||
use core::panic::PanicInfo;
|
||||
use cortex_a::asm;
|
||||
|
||||
#[panic_handler]
|
||||
fn panic(info: &PanicInfo) -> ! {
|
||||
if let Some(args) = info.message() {
|
||||
println!("{}", args);
|
||||
} else {
|
||||
println!("Kernel panic!");
|
||||
}
|
||||
|
||||
loop {
|
||||
asm::wfe();
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,36 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! Trait definitions for coupling `kernel` and `BSP` code.
|
||||
//!
|
||||
//! ```
|
||||
//! +-------------------+
|
||||
//! | Interface (Trait) |
|
||||
//! | |
|
||||
//! +--+-------------+--+
|
||||
//! ^ ^
|
||||
//! | |
|
||||
//! | |
|
||||
//! +----------+--+ +--+----------+
|
||||
//! | Kernel code | | BSP Code |
|
||||
//! | | | |
|
||||
//! +-------------+ +-------------+
|
||||
//! ```
|
||||
|
||||
/// System console operations.
|
||||
pub mod console {
|
||||
/// Console write functions.
|
||||
///
|
||||
/// `core::fmt::Write` is exactly what we need. Re-export it here because
|
||||
/// implementing `console::Write` gives a better hint to the reader about
|
||||
/// the intention.
|
||||
pub use core::fmt::Write;
|
||||
|
||||
/// Console read functions.
|
||||
pub trait Read {
|
||||
fn read_char(&mut self) -> char {
|
||||
' '
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,37 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
// Rust embedded logo for `make doc`.
|
||||
#![doc(html_logo_url = "https://git.io/JeGIp")]
|
||||
|
||||
//! The `kernel`
|
||||
//!
|
||||
//! The `kernel` is composed by glueing together hardware-specific Board Support
|
||||
//! Package (`BSP`) code and hardware-agnostic `kernel` code through the
|
||||
//! [`kernel::interface`] traits.
|
||||
//!
|
||||
//! [`kernel::interface`]: interface/index.html
|
||||
|
||||
#![feature(format_args_nl)]
|
||||
#![feature(panic_info_message)]
|
||||
#![no_main]
|
||||
#![no_std]
|
||||
|
||||
// This module conditionally includes the correct `BSP` which provides the
|
||||
// `_start()` function, the first function to run.
|
||||
mod bsp;
|
||||
|
||||
// Afterwards, `BSP`'s early init code calls `runtime_init::init()` of this
|
||||
// module, which on completion, jumps to `kernel_entry()`.
|
||||
mod runtime_init;
|
||||
|
||||
mod interface;
|
||||
mod print;
|
||||
|
||||
/// Entrypoint of the `kernel`.
|
||||
fn kernel_entry() -> ! {
|
||||
println!("Hello from pure Rust!");
|
||||
|
||||
panic!("Stopping here.")
|
||||
}
|
||||
@ -0,0 +1,32 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! Printing facilities.
|
||||
|
||||
use crate::bsp;
|
||||
use crate::interface::console::Write;
|
||||
use core::fmt;
|
||||
|
||||
/// Prints without a newline.
|
||||
///
|
||||
/// Carbon copy from https://doc.rust-lang.org/src/std/macros.rs.html
|
||||
#[macro_export]
|
||||
macro_rules! print {
|
||||
($($arg:tt)*) => ($crate::print::_print(format_args!($($arg)*)));
|
||||
}
|
||||
|
||||
/// Prints with a newline.
|
||||
///
|
||||
/// Carbon copy from https://doc.rust-lang.org/src/std/macros.rs.html
|
||||
#[macro_export]
|
||||
macro_rules! println {
|
||||
() => ($crate::print!("\n"));
|
||||
($($arg:tt)*) => ({
|
||||
$crate::print::_print(format_args_nl!($($arg)*));
|
||||
})
|
||||
}
|
||||
|
||||
pub fn _print(args: fmt::Arguments) {
|
||||
bsp::console().write_fmt(args).unwrap();
|
||||
}
|
||||
@ -0,0 +1,27 @@
|
||||
// SPDX-License-Identifier: MIT
|
||||
//
|
||||
// Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
|
||||
|
||||
//! Rust runtime initialization code.
|
||||
|
||||
/// Equivalent to `crt0` or `c0` code in C/C++ world. Clears the `bss` section,
|
||||
/// then calls the kernel entry.
|
||||
///
|
||||
/// Called from BSP code.
|
||||
///
|
||||
/// # Safety
|
||||
///
|
||||
/// - Only a single core must be active and running this function.
|
||||
#[no_mangle]
|
||||
pub unsafe fn init() -> ! {
|
||||
extern "C" {
|
||||
// Boundaries of the .bss section, provided by the linker script
|
||||
static mut __bss_start: u64;
|
||||
static mut __bss_end: u64;
|
||||
}
|
||||
|
||||
// Zero out the .bss section
|
||||
r0::zero_bss(&mut __bss_start, &mut __bss_end);
|
||||
|
||||
crate::kernel_entry()
|
||||
}
|
||||
Loading…
Reference in New Issue