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More chainloader cleanup

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closes #79
pull/84/head
Andre Richter 4 years ago
parent 3944bba140
commit eb69b6f861
No known key found for this signature in database
GPG Key ID: 2116C1AB102F615E
8 changed files with 286 additions and 96 deletions
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145
07_uart_chainloader/README.md
Unescape Escape View File

@ -202,6 +202,26 @@ diff -uNr 06_drivers_gpio_uart/src/_arch/aarch64/cpu.rs 07_uart_chainloader/src/
} else {
// If not core0, infinitely wait for events.
wait_forever()
@@ -54,3 +54,19 @@
asm::wfe()
}
}
+
+/// Branch to a raw integer value.
+///
+/// # Safety
+///
+/// - This is highly unsafe. Use with care.
+#[inline(always)]
+pub unsafe fn branch_to_raw_addr(addr: usize) -> ! {
+ asm!(
+ "blr {destination:x}",
+ destination = in(reg) addr,
+ options(nomem, nostack)
+ );
+
+ core::intrinsics::unreachable()
+}
diff -uNr 06_drivers_gpio_uart/src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs 07_uart_chainloader/src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs
--- 06_drivers_gpio_uart/src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs
@ -258,7 +278,7 @@ diff -uNr 06_drivers_gpio_uart/src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs 0
diff -uNr 06_drivers_gpio_uart/src/bsp/raspberrypi/link.ld 07_uart_chainloader/src/bsp/raspberrypi/link.ld
--- 06_drivers_gpio_uart/src/bsp/raspberrypi/link.ld
+++ 07_uart_chainloader/src/bsp/raspberrypi/link.ld
@@ -5,9 +5,10 @@
@@ -5,12 +5,16 @@
SECTIONS
{
@ -270,8 +290,15 @@ diff -uNr 06_drivers_gpio_uart/src/bsp/raspberrypi/link.ld 07_uart_chainloader/s
+ __binary_start = .;
.text :
{
*(.text._start) *(.text*)
@@ -32,5 +33,14 @@
- *(.text._start) *(.text*)
+ *(.text._start)
+ __runtime_init = .;
+ KEEP(*(.text.runtime_init))
+ *(.text*);
}
.rodata :
@@ -32,5 +36,14 @@
__bss_end_inclusive = . - 8;
}
@ -290,16 +317,17 @@ diff -uNr 06_drivers_gpio_uart/src/bsp/raspberrypi/link.ld 07_uart_chainloader/s
diff -uNr 06_drivers_gpio_uart/src/bsp/raspberrypi/memory.rs 07_uart_chainloader/src/bsp/raspberrypi/memory.rs
--- 06_drivers_gpio_uart/src/bsp/raspberrypi/memory.rs
+++ 07_uart_chainloader/src/bsp/raspberrypi/memory.rs
@@ -12,6 +12,8 @@
@@ -12,6 +12,9 @@
// Symbols from the linker script.
extern "Rust" {
+ static __binary_start: UnsafeCell<u64>;
+ static __binary_end_inclusive: UnsafeCell<u64>;
+ static __runtime_init: UnsafeCell<u64>;
static __bss_start: UnsafeCell<u64>;
static __bss_end_inclusive: UnsafeCell<u64>;
}
@@ -23,10 +25,12 @@
@@ -23,10 +26,12 @@
/// The board's memory map.
#[rustfmt::skip]
pub(super) mod map {
@ -315,29 +343,43 @@ diff -uNr 06_drivers_gpio_uart/src/bsp/raspberrypi/memory.rs 07_uart_chainloader
/// Physical devices.
#[cfg(feature = "bsp_rpi3")]
@@ -59,6 +63,22 @@
@@ -59,12 +64,34 @@
map::BOOT_CORE_STACK_END
}
-/// Return the inclusive range spanning the .bss section.
+/// The address on which the Raspberry firmware loads every binary by default.
+#[inline(always)]
+pub fn board_default_load_addr() -> *const u64 {
+ map::BOARD_DEFAULT_LOAD_ADDRESS as _
+}
+
+/// Return the inclusive range spanning the whole binary.
+/// Return the inclusive range spanning the relocated kernel binary.
+///
+/// # Safety
+///
+/// - Values are provided by the linker script and must be trusted as-is.
+/// - The linker-provided addresses must be u64 aligned.
+pub fn binary_range_inclusive() -> RangeInclusive<*mut u64> {
+pub fn relocated_binary_range_inclusive() -> RangeInclusive<*mut u64> {
+ unsafe { RangeInclusive::new(__binary_start.get(), __binary_end_inclusive.get()) }
+}
+
/// Return the inclusive range spanning the .bss section.
+/// The relocated address of function `runtime_init()`.
+#[inline(always)]
+pub fn relocated_runtime_init_addr() -> *const u64 {
+ unsafe { __runtime_init.get() as _ }
+}
+
+/// Return the inclusive range spanning the relocated .bss section.
///
/// # Safety
///
/// - Values are provided by the linker script and must be trusted as-is.
/// - The linker-provided addresses must be u64 aligned.
-pub fn bss_range_inclusive() -> RangeInclusive<*mut u64> {
+pub fn relocated_bss_range_inclusive() -> RangeInclusive<*mut u64> {
unsafe { RangeInclusive::new(__bss_start.get(), __bss_end_inclusive.get()) }
}
diff -uNr 06_drivers_gpio_uart/src/console.rs 07_uart_chainloader/src/console.rs
--- 06_drivers_gpio_uart/src/console.rs
@ -367,7 +409,16 @@ diff -uNr 06_drivers_gpio_uart/src/console.rs 07_uart_chainloader/src/console.rs
diff -uNr 06_drivers_gpio_uart/src/main.rs 07_uart_chainloader/src/main.rs
--- 06_drivers_gpio_uart/src/main.rs
+++ 07_uart_chainloader/src/main.rs
@@ -108,7 +108,8 @@
@@ -100,6 +100,8 @@
//! - `crate::memory::*`
//! - `crate::bsp::memory::*`
+#![feature(asm)]
+#![feature(core_intrinsics)]
#![feature(format_args_nl)]
#![feature(naked_functions)]
#![feature(panic_info_message)]
@@ -108,7 +110,8 @@
#![no_std]
// `mod cpu` provides the `_start()` function, the first function to run. `_start()` then calls
@ -377,7 +428,7 @@ diff -uNr 06_drivers_gpio_uart/src/main.rs 07_uart_chainloader/src/main.rs
mod bsp;
mod console;
@@ -117,6 +118,7 @@
@@ -117,6 +120,7 @@
mod memory;
mod panic_wait;
mod print;
@ -385,7 +436,7 @@ diff -uNr 06_drivers_gpio_uart/src/main.rs 07_uart_chainloader/src/main.rs
mod runtime_init;
mod synchronization;
@@ -143,35 +145,52 @@
@@ -143,35 +147,52 @@
/// The main function running after the early init.
fn kernel_main() -> ! {
@ -447,7 +498,7 @@ diff -uNr 06_drivers_gpio_uart/src/main.rs 07_uart_chainloader/src/main.rs
- println!(" {}. {}", i + 1, driver.compatible());
- }
+ // Use black magic to get a function pointer.
+ let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr as *const ()) };
+ let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr) };
- println!(
- "[2] Chars written: {}",
@ -466,55 +517,81 @@ diff -uNr 06_drivers_gpio_uart/src/main.rs 07_uart_chainloader/src/main.rs
diff -uNr 06_drivers_gpio_uart/src/relocate.rs 07_uart_chainloader/src/relocate.rs
--- 06_drivers_gpio_uart/src/relocate.rs
+++ 07_uart_chainloader/src/relocate.rs
@@ -0,0 +1,49 @@
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+//
+// Copyright (c) 2018-2020 Andre Richter <andre.o.richter@gmail.com>
+
+//! Relocation code.
+
+use crate::{bsp, runtime_init};
+use crate::{bsp, cpu};
+
+//--------------------------------------------------------------------------------------------------
+// Public Code
+//--------------------------------------------------------------------------------------------------
+
+/// Relocates the own binary from `bsp::cpu::BOARD_DEFAULT_LOAD_ADDRESS` to the `__binary_start`
+/// Relocates the own binary from `bsp::memory::board_default_load_addr()` to the `__binary_start`
+/// address from the linker script.
+///
+/// # Safety
+///
+/// - Only a single core must be active and running this function.
+/// - Function must not use the `bss` section.
+#[inline(never)]
+pub unsafe fn relocate_self() -> ! {
+ let range = bsp::memory::binary_range_inclusive();
+ let mut reloc_destination_addr = *range.start();
+ let reloc_end_addr_inclusive = *range.end();
+ let range = bsp::memory::relocated_binary_range_inclusive();
+ let mut relocated_binary_start_addr = *range.start();
+ let relocated_binary_end_addr_inclusive = *range.end();
+
+ // The address of where the previous firmware loaded us.
+ let mut src_addr = bsp::memory::board_default_load_addr();
+
+ // TODO Make it work for the case src_addr > reloc_addr as well.
+ let diff = reloc_destination_addr as usize - src_addr as usize;
+ let mut current_binary_start_addr = bsp::memory::board_default_load_addr();
+
+ // Copy the whole binary.
+ //
+ // This is essentially a `memcpy()` optimized for throughput by transferring in chunks of T.
+ loop {
+ core::ptr::write_volatile(reloc_destination_addr, core::ptr::read_volatile(src_addr));
+ reloc_destination_addr = reloc_destination_addr.offset(1);
+ src_addr = src_addr.offset(1);
+ core::ptr::write_volatile(
+ relocated_binary_start_addr,
+ core::ptr::read_volatile(current_binary_start_addr),
+ );
+ relocated_binary_start_addr = relocated_binary_start_addr.offset(1);
+ current_binary_start_addr = current_binary_start_addr.offset(1);
+
+ if reloc_destination_addr > reloc_end_addr_inclusive {
+ if relocated_binary_start_addr > relocated_binary_end_addr_inclusive {
+ break;
+ }
+ }
+
+ let relocated_runtime_init_addr = runtime_init::runtime_init as *const () as usize + diff;
+ let relocated_runtime_init: fn() -> ! =
+ core::mem::transmute(relocated_runtime_init_addr as *const ());
+
+ relocated_runtime_init()
+ // The following function calls form a hack to achieve an "absolute jump" to
+ // `runtime_init::runtime_init()` by forcing an indirection through the global offset table
+ // (GOT), so that execution continues from the relocated binary.
+ //
+ // Without this, the address of `runtime_init()` would be calculated as a relative offset from
+ // the current program counter, since we are compiling as `position independent code`. This
+ // would cause us to keep executing from the address to which the firmware loaded us, instead of
+ // the relocated position.
+ //
+ // There likely is a more elegant way to do this.
+ let relocated_runtime_init_addr = bsp::memory::relocated_runtime_init_addr() as usize;
+ cpu::branch_to_raw_addr(relocated_runtime_init_addr)
+}
diff -uNr 06_drivers_gpio_uart/src/runtime_init.rs 07_uart_chainloader/src/runtime_init.rs
--- 06_drivers_gpio_uart/src/runtime_init.rs
+++ 07_uart_chainloader/src/runtime_init.rs
@@ -17,7 +17,7 @@
/// - Must only be called pre `kernel_init()`.
#[inline(always)]
unsafe fn zero_bss() {
- memory::zero_volatile(bsp::memory::bss_range_inclusive());
+ memory::zero_volatile(bsp::memory::relocated_bss_range_inclusive());
}
//--------------------------------------------------------------------------------------------------
@@ -30,6 +30,7 @@
/// # Safety
///
/// - Only a single core must be active and running this function.
+#[no_mangle]
pub unsafe fn runtime_init() -> ! {
zero_bss();
```

16
07_uart_chainloader/src/_arch/aarch64/cpu.rs
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@ -54,3 +54,19 @@ pub fn wait_forever() -> ! {
asm::wfe()
}
}
/// Branch to a raw integer value.
///
/// # Safety
///
/// - This is highly unsafe. Use with care.
#[inline(always)]
pub unsafe fn branch_to_raw_addr(addr: usize) -> ! {
asm!(
"blr {destination:x}",
destination = in(reg) addr,
options(nomem, nostack)
);
core::intrinsics::unreachable()
}

5
07_uart_chainloader/src/bsp/raspberrypi/link.ld
Unescape Escape View File

@ -11,7 +11,10 @@ SECTIONS
__binary_start = .;
.text :
{
*(.text._start) *(.text*)
*(.text._start)
__runtime_init = .;
KEEP(*(.text.runtime_init))
*(.text*);
}
.rodata :

15
07_uart_chainloader/src/bsp/raspberrypi/memory.rs
Unescape Escape View File

@ -14,6 +14,7 @@ use core::{cell::UnsafeCell, ops::RangeInclusive};
extern "Rust" {
static __binary_start: UnsafeCell<u64>;
static __binary_end_inclusive: UnsafeCell<u64>;
static __runtime_init: UnsafeCell<u64>;
static __bss_start: UnsafeCell<u64>;
static __bss_end_inclusive: UnsafeCell<u64>;
}
@ -69,22 +70,28 @@ pub fn board_default_load_addr() -> *const u64 {
map::BOARD_DEFAULT_LOAD_ADDRESS as _
}
/// Return the inclusive range spanning the whole binary.
/// Return the inclusive range spanning the relocated kernel binary.
///
/// # Safety
///
/// - Values are provided by the linker script and must be trusted as-is.
/// - The linker-provided addresses must be u64 aligned.
pub fn binary_range_inclusive() -> RangeInclusive<*mut u64> {
pub fn relocated_binary_range_inclusive() -> RangeInclusive<*mut u64> {
unsafe { RangeInclusive::new(__binary_start.get(), __binary_end_inclusive.get()) }
}
/// Return the inclusive range spanning the .bss section.
/// The relocated address of function `runtime_init()`.
#[inline(always)]
pub fn relocated_runtime_init_addr() -> *const u64 {
unsafe { __runtime_init.get() as _ }
}
/// Return the inclusive range spanning the relocated .bss section.
///
/// # Safety
///
/// - Values are provided by the linker script and must be trusted as-is.
/// - The linker-provided addresses must be u64 aligned.
pub fn bss_range_inclusive() -> RangeInclusive<*mut u64> {
pub fn relocated_bss_range_inclusive() -> RangeInclusive<*mut u64> {
unsafe { RangeInclusive::new(__bss_start.get(), __bss_end_inclusive.get()) }
}

4
07_uart_chainloader/src/main.rs
Unescape Escape View File

@ -100,6 +100,8 @@
//! - `crate::memory::*`
//! - `crate::bsp::memory::*`
#![feature(asm)]
#![feature(core_intrinsics)]
#![feature(format_args_nl)]
#![feature(naked_functions)]
#![feature(panic_info_message)]
@ -189,7 +191,7 @@ fn kernel_main() -> ! {
console().flush();
// Use black magic to get a function pointer.
let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr as *const ()) };
let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr) };
// Jump to loaded kernel!
kernel()

48
07_uart_chainloader/src/relocate.rs
Unescape Escape View File

@ -4,46 +4,52 @@
//! Relocation code.
use crate::{bsp, runtime_init};
use crate::{bsp, cpu};
//--------------------------------------------------------------------------------------------------
// Public Code
//--------------------------------------------------------------------------------------------------
/// Relocates the own binary from `bsp::cpu::BOARD_DEFAULT_LOAD_ADDRESS` to the `__binary_start`
/// Relocates the own binary from `bsp::memory::board_default_load_addr()` to the `__binary_start`
/// address from the linker script.
///
/// # Safety
///
/// - Only a single core must be active and running this function.
/// - Function must not use the `bss` section.
#[inline(never)]
pub unsafe fn relocate_self() -> ! {
let range = bsp::memory::binary_range_inclusive();
let mut reloc_destination_addr = *range.start();
let reloc_end_addr_inclusive = *range.end();
let range = bsp::memory::relocated_binary_range_inclusive();
let mut relocated_binary_start_addr = *range.start();
let relocated_binary_end_addr_inclusive = *range.end();
// The address of where the previous firmware loaded us.
let mut src_addr = bsp::memory::board_default_load_addr();
// TODO Make it work for the case src_addr > reloc_addr as well.
let diff = reloc_destination_addr as usize - src_addr as usize;
let mut current_binary_start_addr = bsp::memory::board_default_load_addr();
// Copy the whole binary.
//
// This is essentially a `memcpy()` optimized for throughput by transferring in chunks of T.
loop {
core::ptr::write_volatile(reloc_destination_addr, core::ptr::read_volatile(src_addr));
reloc_destination_addr = reloc_destination_addr.offset(1);
src_addr = src_addr.offset(1);
if reloc_destination_addr > reloc_end_addr_inclusive {
core::ptr::write_volatile(
relocated_binary_start_addr,
core::ptr::read_volatile(current_binary_start_addr),
);
relocated_binary_start_addr = relocated_binary_start_addr.offset(1);
current_binary_start_addr = current_binary_start_addr.offset(1);
if relocated_binary_start_addr > relocated_binary_end_addr_inclusive {
break;
}
}
let relocated_runtime_init_addr = runtime_init::runtime_init as *const () as usize + diff;
let relocated_runtime_init: fn() -> ! =
core::mem::transmute(relocated_runtime_init_addr as *const ());
relocated_runtime_init()
// The following function calls form a hack to achieve an "absolute jump" to
// `runtime_init::runtime_init()` by forcing an indirection through the global offset table
// (GOT), so that execution continues from the relocated binary.
//
// Without this, the address of `runtime_init()` would be calculated as a relative offset from
// the current program counter, since we are compiling as `position independent code`. This
// would cause us to keep executing from the address to which the firmware loaded us, instead of
// the relocated position.
//
// There likely is a more elegant way to do this.
let relocated_runtime_init_addr = bsp::memory::relocated_runtime_init_addr() as usize;
cpu::branch_to_raw_addr(relocated_runtime_init_addr)
}

3
07_uart_chainloader/src/runtime_init.rs
Unescape Escape View File

@ -17,7 +17,7 @@ use crate::{bsp, memory};
/// - Must only be called pre `kernel_init()`.
#[inline(always)]
unsafe fn zero_bss() {
memory::zero_volatile(bsp::memory::bss_range_inclusive());
memory::zero_volatile(bsp::memory::relocated_bss_range_inclusive());
}
//--------------------------------------------------------------------------------------------------
@ -30,6 +30,7 @@ unsafe fn zero_bss() {
/// # Safety
///
/// - Only a single core must be active and running this function.
#[no_mangle]
pub unsafe fn runtime_init() -> ! {
zero_bss();

146
08_timestamps/README.md
Unescape Escape View File

@ -118,6 +118,26 @@ diff -uNr 07_uart_chainloader/src/_arch/aarch64/cpu.rs 08_timestamps/src/_arch/a
} else {
// If not core0, infinitely wait for events.
wait_forever()
@@ -54,19 +54,3 @@
asm::wfe()
}
}
-
-/// Branch to a raw integer value.
-///
-/// # Safety
-///
-/// - This is highly unsafe. Use with care.
-#[inline(always)]
-pub unsafe fn branch_to_raw_addr(addr: usize) -> ! {
- asm!(
- "blr {destination:x}",
- destination = in(reg) addr,
- options(nomem, nostack)
- );
-
- core::intrinsics::unreachable()
-}
diff -uNr 07_uart_chainloader/src/_arch/aarch64/time.rs 08_timestamps/src/_arch/aarch64/time.rs
--- 07_uart_chainloader/src/_arch/aarch64/time.rs
@ -250,7 +270,7 @@ diff -uNr 07_uart_chainloader/src/bsp/device_driver/bcm/bcm2xxx_pl011_uart.rs 08
diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/link.ld 08_timestamps/src/bsp/raspberrypi/link.ld
--- 07_uart_chainloader/src/bsp/raspberrypi/link.ld
+++ 08_timestamps/src/bsp/raspberrypi/link.ld
@@ -5,10 +5,9 @@
@@ -5,16 +5,12 @@
SECTIONS
{
@ -262,8 +282,15 @@ diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/link.ld 08_timestamps/src/bsp/
- __binary_start = .;
.text :
{
*(.text._start) *(.text*)
@@ -33,14 +32,5 @@
- *(.text._start)
- __runtime_init = .;
- KEEP(*(.text.runtime_init))
- *(.text*);
+ *(.text._start) *(.text*)
}
.rodata :
@@ -36,14 +32,5 @@
__bss_end_inclusive = . - 8;
}
@ -282,16 +309,17 @@ diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/link.ld 08_timestamps/src/bsp/
diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/memory.rs 08_timestamps/src/bsp/raspberrypi/memory.rs
--- 07_uart_chainloader/src/bsp/raspberrypi/memory.rs
+++ 08_timestamps/src/bsp/raspberrypi/memory.rs
@@ -12,8 +12,6 @@
@@ -12,9 +12,6 @@
// Symbols from the linker script.
extern "Rust" {
- static __binary_start: UnsafeCell<u64>;
- static __binary_end_inclusive: UnsafeCell<u64>;
- static __runtime_init: UnsafeCell<u64>;
static __bss_start: UnsafeCell<u64>;
static __bss_end_inclusive: UnsafeCell<u64>;
}
@@ -25,12 +23,10 @@
@@ -26,12 +23,10 @@
/// The board's memory map.
#[rustfmt::skip]
pub(super) mod map {
@ -307,7 +335,7 @@ diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/memory.rs 08_timestamps/src/bs
/// Physical devices.
#[cfg(feature = "bsp_rpi3")]
@@ -63,22 +59,6 @@
@@ -64,34 +59,12 @@
map::BOOT_CORE_STACK_END
}
@ -317,19 +345,33 @@ diff -uNr 07_uart_chainloader/src/bsp/raspberrypi/memory.rs 08_timestamps/src/bs
- map::BOARD_DEFAULT_LOAD_ADDRESS as _
-}
-
-/// Return the inclusive range spanning the whole binary.
-/// Return the inclusive range spanning the relocated kernel binary.
-///
-/// # Safety
-///
-/// - Values are provided by the linker script and must be trusted as-is.
-/// - The linker-provided addresses must be u64 aligned.
-pub fn binary_range_inclusive() -> RangeInclusive<*mut u64> {
-pub fn relocated_binary_range_inclusive() -> RangeInclusive<*mut u64> {
- unsafe { RangeInclusive::new(__binary_start.get(), __binary_end_inclusive.get()) }
-}
-
/// Return the inclusive range spanning the .bss section.
-/// The relocated address of function `runtime_init()`.
-#[inline(always)]
-pub fn relocated_runtime_init_addr() -> *const u64 {
- unsafe { __runtime_init.get() as _ }
-}
-
-/// Return the inclusive range spanning the relocated .bss section.
+/// Return the inclusive range spanning the .bss section.
///
/// # Safety
///
/// - Values are provided by the linker script and must be trusted as-is.
/// - The linker-provided addresses must be u64 aligned.
-pub fn relocated_bss_range_inclusive() -> RangeInclusive<*mut u64> {
+pub fn bss_range_inclusive() -> RangeInclusive<*mut u64> {
unsafe { RangeInclusive::new(__bss_start.get(), __bss_end_inclusive.get()) }
}
diff -uNr 07_uart_chainloader/src/main.rs 08_timestamps/src/main.rs
--- 07_uart_chainloader/src/main.rs
@ -346,7 +388,16 @@ diff -uNr 07_uart_chainloader/src/main.rs 08_timestamps/src/main.rs
//!
//! # Code organization and architecture
//!
@@ -108,8 +110,7 @@
@@ -100,8 +102,6 @@
//! - `crate::memory::*`
//! - `crate::bsp::memory::*`
-#![feature(asm)]
-#![feature(core_intrinsics)]
#![feature(format_args_nl)]
#![feature(naked_functions)]
#![feature(panic_info_message)]
@@ -110,8 +110,7 @@
#![no_std]
// `mod cpu` provides the `_start()` function, the first function to run. `_start()` then calls
@ -356,7 +407,7 @@ diff -uNr 07_uart_chainloader/src/main.rs 08_timestamps/src/main.rs
mod bsp;
mod console;
@@ -118,9 +119,9 @@
@@ -120,9 +119,9 @@
mod memory;
mod panic_wait;
mod print;
@ -367,7 +418,7 @@ diff -uNr 07_uart_chainloader/src/main.rs 08_timestamps/src/main.rs
/// Early init code.
///
@@ -145,52 +146,31 @@
@@ -147,52 +146,31 @@
/// The main function running after the early init.
fn kernel_main() -> ! {
@ -433,7 +484,7 @@ diff -uNr 07_uart_chainloader/src/main.rs 08_timestamps/src/main.rs
+ time::time_manager().spin_for(Duration::from_nanos(1));
- // Use black magic to get a function pointer.
- let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr as *const ()) };
- let kernel: fn() -> ! = unsafe { core::mem::transmute(kernel_addr) };
-
- // Jump to loaded kernel!
- kernel()
@ -522,57 +573,84 @@ diff -uNr 07_uart_chainloader/src/print.rs 08_timestamps/src/print.rs
diff -uNr 07_uart_chainloader/src/relocate.rs 08_timestamps/src/relocate.rs
--- 07_uart_chainloader/src/relocate.rs
+++ 08_timestamps/src/relocate.rs
@@ -1,49 +0,0 @@
@@ -1,55 +0,0 @@
-// SPDX-License-Identifier: MIT OR Apache-2.0
-//
-// Copyright (c) 2018-2020 Andre Richter <andre.o.richter@gmail.com>
-
-//! Relocation code.
-
-use crate::{bsp, runtime_init};
-use crate::{bsp, cpu};
-
-//--------------------------------------------------------------------------------------------------
-// Public Code
-//--------------------------------------------------------------------------------------------------
-
-/// Relocates the own binary from `bsp::cpu::BOARD_DEFAULT_LOAD_ADDRESS` to the `__binary_start`
-/// Relocates the own binary from `bsp::memory::board_default_load_addr()` to the `__binary_start`
-/// address from the linker script.
-///
-/// # Safety
-///
-/// - Only a single core must be active and running this function.
-/// - Function must not use the `bss` section.
-#[inline(never)]
-pub unsafe fn relocate_self() -> ! {
- let range = bsp::memory::binary_range_inclusive();
- let mut reloc_destination_addr = *range.start();
- let reloc_end_addr_inclusive = *range.end();
- let range = bsp::memory::relocated_binary_range_inclusive();
- let mut relocated_binary_start_addr = *range.start();
- let relocated_binary_end_addr_inclusive = *range.end();
-
- // The address of where the previous firmware loaded us.
- let mut src_addr = bsp::memory::board_default_load_addr();
-
- // TODO Make it work for the case src_addr > reloc_addr as well.
- let diff = reloc_destination_addr as usize - src_addr as usize;
- let mut current_binary_start_addr = bsp::memory::board_default_load_addr();
-
- // Copy the whole binary.
- //
- // This is essentially a `memcpy()` optimized for throughput by transferring in chunks of T.
- loop {
- core::ptr::write_volatile(reloc_destination_addr, core::ptr::read_volatile(src_addr));
- reloc_destination_addr = reloc_destination_addr.offset(1);
- src_addr = src_addr.offset(1);
- core::ptr::write_volatile(
- relocated_binary_start_addr,
- core::ptr::read_volatile(current_binary_start_addr),
- );
- relocated_binary_start_addr = relocated_binary_start_addr.offset(1);
- current_binary_start_addr = current_binary_start_addr.offset(1);
-
- if reloc_destination_addr > reloc_end_addr_inclusive {
- if relocated_binary_start_addr > relocated_binary_end_addr_inclusive {
- break;
- }
- }
-
- let relocated_runtime_init_addr = runtime_init::runtime_init as *const () as usize + diff;
- let relocated_runtime_init: fn() -> ! =
- core::mem::transmute(relocated_runtime_init_addr as *const ());
-
- relocated_runtime_init()
- // The following function calls form a hack to achieve an "absolute jump" to
- // `runtime_init::runtime_init()` by forcing an indirection through the global offset table
- // (GOT), so that execution continues from the relocated binary.
- //
- // Without this, the address of `runtime_init()` would be calculated as a relative offset from
- // the current program counter, since we are compiling as `position independent code`. This
- // would cause us to keep executing from the address to which the firmware loaded us, instead of
- // the relocated position.
- //
- // There likely is a more elegant way to do this.
- let relocated_runtime_init_addr = bsp::memory::relocated_runtime_init_addr() as usize;
- cpu::branch_to_raw_addr(relocated_runtime_init_addr)
-}
diff -uNr 07_uart_chainloader/src/runtime_init.rs 08_timestamps/src/runtime_init.rs
--- 07_uart_chainloader/src/runtime_init.rs
+++ 08_timestamps/src/runtime_init.rs
@@ -17,7 +17,7 @@
/// - Must only be called pre `kernel_init()`.
#[inline(always)]
unsafe fn zero_bss() {
- memory::zero_volatile(bsp::memory::relocated_bss_range_inclusive());
+ memory::zero_volatile(bsp::memory::bss_range_inclusive());
}
//--------------------------------------------------------------------------------------------------
@@ -30,7 +30,6 @@
/// # Safety
///
/// - Only a single core must be active and running this function.
-#[no_mangle]
pub unsafe fn runtime_init() -> ! {
zero_bss();
diff -uNr 07_uart_chainloader/src/time.rs 08_timestamps/src/time.rs
--- 07_uart_chainloader/src/time.rs
+++ 08_timestamps/src/time.rs

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