Node / public / precursor-lxmfchat.git / files / xous-core / kernel / src / debug / gdb / single_register_access.rs

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use core::convert::TryInto;

use gdbstub::common::Tid;

use gdbstub::target::ext::base::single_register_access::SingleRegisterAccess;

use gdbstub::target::{TargetError, TargetResult};

use gdbstub_arch::riscv::reg::id::RiscvRegId;

use super::XousTarget;

impl SingleRegisterAccess<Tid> for XousTarget {

fn read_register(

&mut self,

tid: Tid,

reg_id: RiscvRegId<u32>,

buf: &mut [u8],

) -> TargetResult<usize, Self> {

// For the case of no PID, fake a value

let Some(pid) = self.pid else {

buf.copy_from_slice(&0u32.to_le_bytes());

return Ok(buf.len());

};

let reg_id = match reg_id {

RiscvRegId::Gpr(0) => {

buf.copy_from_slice(&0u32.to_le_bytes());

return Ok(buf.len());

}

RiscvRegId::Gpr(x) => x as usize - 1,

RiscvRegId::Pc => 31,

_ => {

return Err(TargetError::Fatal("register out of range"));

}

};

crate::services::SystemServices::with(|system_services| {

let current_pid = system_services.current_pid();

// Actiavte the debugging process and iterate through it,

// noting down each active thread.

let debugging_pid = pid;

system_services.get_process(debugging_pid).unwrap().activate().unwrap();

let process = crate::arch::process::Process::current();

let thread = process.thread(tid.get());

let reg = if reg_id == 31 {

&thread.sepc

} else {

match thread.registers.get(reg_id) {

Some(val) => val,

None => return Err(TargetError::Fatal("register out of range")),

}

};

buf.copy_from_slice(&reg.to_le_bytes());

// Restore the previous PID

system_services.get_process(current_pid).unwrap().activate().unwrap();

Ok(buf.len())

})

}

fn write_register(&mut self, tid: Tid, reg_id: RiscvRegId<u32>, val: &[u8]) -> TargetResult<(), Self> {

let Some(pid) = self.pid else { return Ok(()) };

let w = u32::from_le_bytes(val.try_into().map_err(|_| TargetError::Fatal("invalid data"))?);

let reg_id = match reg_id {

RiscvRegId::Gpr(0) => {

return Ok(());

}

RiscvRegId::Gpr(x) => x as usize - 1,

RiscvRegId::Pc => 31,

_ => {

return Err(TargetError::Fatal("register out of range"));

}

};

crate::services::SystemServices::with(|system_services| {

let current_pid = system_services.current_pid();

// Actiavte the debugging process and iterate through it,

// noting down each active thread.

let debugging_pid = pid;

system_services.get_process(debugging_pid).unwrap().activate().unwrap();

let mut process = crate::arch::process::Process::current();

let thread = process.thread_mut(tid.get());

let reg = if reg_id == 31 {

&mut thread.sepc

} else {

match thread.registers.get_mut(reg_id) {

Some(val) => val,

None => return Err(TargetError::Fatal("register out of range")),

}

};

*reg = w as usize;

// Restore the previous PID

system_services.get_process(current_pid).unwrap().activate().unwrap();

Ok(())

})

}

}