artiq/artiq/firmware/libboard_misoc/riscv32imac/boot.rs

49 lines
1.1 KiB
Rust

use super::{irq, cache};
pub unsafe fn reset() -> ! {
irq::set_ie(false);
llvm_asm!(r#"
j _reset_handler
nop
"# : : : : "volatile");
loop {}
}
pub unsafe fn jump(addr: usize) -> ! {
irq::set_ie(false);
cache::flush_cpu_icache();
llvm_asm!(r#"
jalr x0, 0($0)
nop
"# : : "r"(addr) : : "volatile");
loop {}
}
pub unsafe fn hotswap(firmware: &[u8]) -> ! {
irq::set_ie(false);
llvm_asm!(r#"
# This loop overwrites itself, but it's structured in such a way
# that before that happens, it loads itself into I$$ fully.
lui a1, %hi(_reset_handler)
ori a1, a1, %lo(_reset_handler)
or a4, a1, zero
0: bnez a2, 1f
nop
jr a4
nop
1: lw a3, 0(a0)
sw a3, 0(a1)
addi a0, a0, 4
addi a1, a1, 4
addi a2, a2, -4
bnez a2, 0b
nop
"#
:
: "{a0}"(firmware.as_ptr() as usize),
"{a2}"(firmware.len())
:
: "volatile");
loop {}
}