vesper/nucleus/src/main.rs

367 lines
11 KiB
Rust

/*
* SPDX-License-Identifier: BlueOak-1.0.0
* Copyright (c) Berkus Decker <berkus+vesper@metta.systems>
*/
//! Vesper single-address-space exokernel.
//!
//! This crate implements the kernel binary proper.
#![no_std]
#![no_main]
#![feature(asm)]
#![feature(global_asm)]
#![feature(decl_macro)]
#![feature(allocator_api)]
#![feature(ptr_internals)]
#![feature(format_args_nl)]
#![feature(result_contains_err)]
#![feature(nonnull_slice_from_raw_parts)]
#![feature(custom_test_frameworks)]
#![test_runner(crate::tests::test_runner)]
#![reexport_test_harness_main = "test_main"]
#![deny(missing_docs)]
#![deny(warnings)]
#![allow(dead_code)] // While working on features, some code may remain unused
// repr128 is not yet stable
#![feature(repr128)]
#![feature(const_generics)]
#![feature(const_evaluatable_checked)] // see https://github.com/rust-lang/rust/issues/68436
#![allow(incomplete_features)]
#[cfg(not(target_arch = "aarch64"))]
use architecture_not_supported_sorry;
/// Architecture-specific code.
#[macro_use]
pub mod arch;
pub use arch::*;
mod caps;
mod devices;
mod macros;
mod mm;
mod objects;
mod panic;
mod platform;
#[cfg(feature = "qemu")]
mod qemu;
mod sync;
#[cfg(test)]
mod tests;
mod write_to;
use {
crate::platform::rpi3::{
display::{Color, DrawError},
mailbox::{channel, Mailbox, MailboxOps},
vc::VC,
},
cfg_if::cfg_if,
};
entry!(kmain);
/// The global console. Output of the kernel print! and println! macros goes here.
static CONSOLE: sync::NullLock<devices::Console> = sync::NullLock::new(devices::Console::new());
/// The global allocator for DMA-able memory. That is, memory which is tagged
/// non-cacheable in the page tables.
static DMA_ALLOCATOR: sync::NullLock<mm::BumpAllocator> =
sync::NullLock::new(mm::BumpAllocator::new(
// @todo Init this after we loaded boot memory map
memory::map::virt::DMA_HEAP_START as usize,
memory::map::virt::DMA_HEAP_END as usize,
"Global DMA Allocator",
// Try the following arguments instead to see all mailbox operations
// fail. It will cause the allocator to use memory that are marked
// cacheable and therefore not DMA-safe. The answer from the VideoCore
// won't be received by the CPU because it reads an old cached value
// that resembles an error case instead.
// 0x00600000 as usize,
// 0x007FFFFF as usize,
// "Global Non-DMA Allocator",
));
fn print_mmu_state_and_features() {
memory::mmu::print_features();
}
fn init_mmu() {
unsafe {
memory::mmu::init().unwrap();
}
println!("[!] MMU initialised");
print_mmu_state_and_features();
}
fn init_exception_traps() {
extern "C" {
static __exception_vectors_start: u64;
}
unsafe {
let exception_vectors_start: u64 = &__exception_vectors_start as *const _ as u64;
arch::traps::set_vbar_el1_checked(exception_vectors_start)
.expect("Vector table properly aligned!");
}
println!("[!] Exception traps set up");
}
#[cfg(not(feature = "noserial"))]
fn init_uart_serial() {
use crate::platform::rpi3::{gpio::GPIO, mini_uart::MiniUart, pl011_uart::PL011Uart};
let gpio = GPIO::default();
let uart = MiniUart::default();
let uart = uart.prepare(&gpio);
CONSOLE.lock(|c| {
// Move uart into the global CONSOLE.
c.replace_with(uart.into());
});
println!("[0] MiniUART is live!");
// Then immediately switch to PL011 (just as an example)
let uart = PL011Uart::default();
let mbox = Mailbox::default();
// uart.init() will reconfigure the GPIO, which causes a race against
// the MiniUart that is still putting out characters on the physical
// line that are already buffered in its TX FIFO.
//
// To ensure the CPU doesn't rewire the GPIO before the MiniUart has put
// its last character, explicitly flush it before rewiring.
//
// If you switch to an output that happens to not use the same pair of
// physical wires (e.g. the Framebuffer), you don't need to do this,
// because flush() is anyways called implicitly by replace_with(). This
// is just a special case.
use crate::devices::console::ConsoleOps;
CONSOLE.lock(|c| c.flush());
match uart.prepare(mbox, &gpio) {
Ok(uart) => {
CONSOLE.lock(|c| {
// Move uart into the global CONSOLE.
c.replace_with(uart.into());
});
println!("[0] UART0 is live!");
}
Err(_) => println!("[0] Error switching to PL011 UART, continue with MiniUART"),
}
}
/// Kernel entry point.
/// `arch` crate is responsible for calling it.
#[inline]
pub fn kmain() -> ! {
#[cfg(feature = "jtag")]
jtag::wait_debugger();
init_mmu();
init_exception_traps();
#[cfg(not(feature = "noserial"))]
init_uart_serial();
#[cfg(test)]
test_main();
/*
try_init_kernel().expect("Failed to init kernel");*/
// schedule();
// activate_thread();
command_prompt();
reboot()
}
//------------------------------------------------------------
// Start a command prompt
//------------------------------------------------------------
fn command_prompt() {
'cmd_loop: loop {
let mut buf = [0u8; 64];
match CONSOLE.lock(|c| c.command_prompt(&mut buf)) {
b"mmu" => init_mmu(),
b"feats" => print_mmu_state_and_features(),
#[cfg(not(feature = "noserial"))]
b"uart" => init_uart_serial(),
b"disp" => check_display_init(),
b"trap" => check_data_abort_trap(),
b"map" => arch::memory::print_layout(),
b"led on" => set_led(true),
b"led off" => set_led(false),
b"help" => print_help(),
b"end" => break 'cmd_loop,
x => println!("[!] Unknown command {:?}, try 'help'", x),
}
}
}
fn print_help() {
println!("Supported console commands:");
println!(" mmu - initialize MMU");
println!(" feats - print MMU state and supported features");
#[cfg(not(feature = "noserial"))]
println!(" uart - try to reinitialize UART serial");
println!(" disp - try to init VC framebuffer and draw some text");
println!(" trap - trigger and recover from a data abort exception");
println!(" map - show kernel memory layout");
println!(" led [on|off] - change RPi LED status");
println!(" end - leave console and reset board");
}
fn set_led(enable: bool) {
let mut mbox = Mailbox::default();
let index = mbox.request();
let index = mbox.set_led_on(index, enable);
let mbox = mbox.end(index);
mbox.call(channel::PropertyTagsArmToVc)
.map_err(|e| {
println!("Mailbox call returned error {}", e);
println!("Mailbox contents: {:?}", mbox);
})
.ok();
}
fn reboot() -> ! {
cfg_if! {
if #[cfg(feature = "qemu")] {
println!("Bye, shutting down QEMU");
qemu::semihosting::exit_success()
} else {
use crate::platform::rpi3::power::Power;
println!("Bye, going to reset now");
Power::new().reset()
}
}
}
#[derive(Debug)]
enum KernelInitError {
CapabilityCreationFailed,
}
// #[link_section = ".text.boot"]
// fn try_init_kernel() -> Result<(), KernelInitError> {
// let root_capnode_cap = create_root_capnode();
// if root_capnode_cap.is_err() {
// return Err(KernelInitError::CapabilityCreationFailed);
// }
// Ok(())
// }
const CONFIG_ROOT_CAPNODE_SIZE_BITS: usize = 12;
const WORD_BITS: usize = 64;
enum BootInfoCaps {
InitThreadCapNode = 1,
}
impl From<BootInfoCaps> for usize {
fn from(val: BootInfoCaps) -> usize {
val as usize
}
}
/*
#[link_section = ".text.boot"]
fn create_root_capnode() -> Result<CapNodeCapability, caps::CapError> {
// write the number of root CNode slots to global state
BOOT_INFO.lock(|bi| bi.max_slot_pos = 1 << CONFIG_ROOT_CAPNODE_SIZE_BITS); // 12 bits => 4096 slots
// seL4_SlotBits = 32 bytes per entry, 4096 entries =>
// create an empty root CapNode
// this goes into the kernel startup/heap memory (one of the few items that kernel DOES allocate).
let region_size = core::mem::size_of::<CapTableEntry>() * BOOT_INFO.lock(|bi| bi.max_slot_pos); // 12 + 5 => 131072 (128Kb)
let pptr = BOOT_INFO.lock(|bi| bi.alloc_region(region_size)); // GlobalAllocator::alloc_zeroed instead?
let pptr = match pptr {
Ok(pptr) => pptr,
Err(_) => {
println!("Kernel init failed: could not create root capnode");
return Err(caps::CapError::CannotCreate);
}
};
// @todo lifetime of slice -- slice here only to zero out memory
let slice =
unsafe { core::slice::from_raw_parts_mut(pptr.as_u64() as *mut u8, region_size as usize) };
for byte in slice.iter_mut() {
*byte = 0;
} // @todo wtf
// transmute into a type? (you can use ptr.write() to just write a type into memory location)
let cap = CapNodeCapability::new_root(pptr.as_u64());
use core::convert::TryFrom;
let mut cap_node = CapNodeCapability::try_from(cap.as_u128()).unwrap();
// this cnode contains a cap to itself...
/* write the root CNode cap into the root CNode */
cap_node.write_slot(usize::from(BootInfoCaps::InitThreadCapNode), &cap);
Ok(cap_node) // reference to pptr is here
}*/
fn check_display_init() {
display_graphics()
.map_err(|e| {
println!("Error in display: {}", e);
})
.ok();
}
fn display_graphics() -> Result<(), DrawError> {
if let Ok(mut display) = VC::init_fb(800, 600, 32) {
println!("Display created");
display.clear(Color::black());
println!("Display cleared");
display.rect(10, 10, 250, 250, Color::rgb(32, 96, 64));
display.draw_text(50, 50, "Hello there!", Color::rgb(128, 192, 255))?;
let mut buf = [0u8; 64];
let s = write_to::show(&mut buf, format_args!("Display width {}", display.width));
if s.is_err() {
display.draw_text(50, 150, "Error displaying", Color::red())?
} else {
display.draw_text(50, 150, s.unwrap(), Color::white())?
}
display.draw_text(150, 50, "RED", Color::red())?;
display.draw_text(160, 60, "GREEN", Color::green())?;
display.draw_text(170, 70, "BLUE", Color::blue())?;
}
Ok(())
}
fn check_data_abort_trap() {
// Cause an exception by accessing a virtual address for which no
// address translations have been set up.
//
// This line of code accesses the address 3 GiB, but page tables are
// only set up for the range [0..1) GiB.
let big_addr: u64 = 3 * 1024 * 1024 * 1024;
unsafe { core::ptr::read_volatile(big_addr as *mut u64) };
println!("[i] Whoa! We recovered from an exception.");
}
#[cfg(test)]
mod main_tests {
use super::*;
#[test_case]
fn test_data_abort_trap() {
check_data_abort_trap()
}
}