From 7304cf4765120f1e81066821fe4566fdee1bc7c2 Mon Sep 17 00:00:00 2001 From: Sean Cross Date: Tue, 6 Aug 2024 22:41:06 +0800 Subject: [PATCH] std: xous: add support for args and env Process arguments and environment variables are both passed by way of Application Parameters. These are a TLV format that gets passed in as the second process argument. This patch combines both as they are very similar in their decode. Signed-off-by: Sean Cross --- library/std/src/sys/pal/xous/args.rs | 53 ++++ library/std/src/sys/pal/xous/mod.rs | 1 - library/std/src/sys/pal/xous/os.rs | 136 +++++++-- library/std/src/sys/pal/xous/os/params.rs | 271 ++++++++++++++++++ .../std/src/sys/pal/xous/os/params/tests.rs | 75 +++++ 5 files changed, 504 insertions(+), 32 deletions(-) create mode 100644 library/std/src/sys/pal/xous/args.rs create mode 100644 library/std/src/sys/pal/xous/os/params.rs create mode 100644 library/std/src/sys/pal/xous/os/params/tests.rs diff --git a/library/std/src/sys/pal/xous/args.rs b/library/std/src/sys/pal/xous/args.rs new file mode 100644 index 0000000000000..00c44ca220a9e --- /dev/null +++ b/library/std/src/sys/pal/xous/args.rs @@ -0,0 +1,53 @@ +use crate::ffi::OsString; +use crate::sys::pal::xous::os::get_application_parameters; +use crate::sys::pal::xous::os::params::ArgumentList; +use crate::{fmt, vec}; + +pub struct Args { + parsed_args_list: vec::IntoIter, +} + +pub fn args() -> Args { + let Some(params) = get_application_parameters() else { + return Args { parsed_args_list: vec![].into_iter() }; + }; + + for param in params { + if let Ok(args) = ArgumentList::try_from(¶m) { + let mut parsed_args = vec![]; + for arg in args { + parsed_args.push(arg.into()); + } + return Args { parsed_args_list: parsed_args.into_iter() }; + } + } + Args { parsed_args_list: vec![].into_iter() } +} + +impl fmt::Debug for Args { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.parsed_args_list.as_slice().fmt(f) + } +} + +impl Iterator for Args { + type Item = OsString; + fn next(&mut self) -> Option { + self.parsed_args_list.next() + } + fn size_hint(&self) -> (usize, Option) { + self.parsed_args_list.size_hint() + } +} + +impl DoubleEndedIterator for Args { + fn next_back(&mut self) -> Option { + self.parsed_args_list.next_back() + } +} + +impl ExactSizeIterator for Args { + fn len(&self) -> usize { + self.parsed_args_list.len() + } +} diff --git a/library/std/src/sys/pal/xous/mod.rs b/library/std/src/sys/pal/xous/mod.rs index b211e94db65d6..a64cd06856006 100644 --- a/library/std/src/sys/pal/xous/mod.rs +++ b/library/std/src/sys/pal/xous/mod.rs @@ -1,6 +1,5 @@ #![forbid(unsafe_op_in_unsafe_fn)] -#[path = "../unsupported/args.rs"] pub mod args; #[path = "../unsupported/env.rs"] pub mod env; diff --git a/library/std/src/sys/pal/xous/os.rs b/library/std/src/sys/pal/xous/os.rs index 8f8f35428c487..b0ab01a6383d2 100644 --- a/library/std/src/sys/pal/xous/os.rs +++ b/library/std/src/sys/pal/xous/os.rs @@ -1,29 +1,35 @@ use super::unsupported; +use crate::collections::HashMap; use crate::error::Error as StdError; use crate::ffi::{OsStr, OsString}; use crate::marker::PhantomData; use crate::os::xous::ffi::Error as XousError; use crate::path::{self, PathBuf}; -use crate::{fmt, io}; +use crate::sync::atomic::{AtomicPtr, AtomicUsize, Ordering}; +use crate::sync::{Mutex, Once}; +use crate::{fmt, io, vec}; + +pub(crate) mod params; + +static PARAMS_ADDRESS: AtomicPtr = AtomicPtr::new(core::ptr::null_mut()); #[cfg(not(test))] #[cfg(feature = "panic_unwind")] mod eh_unwinding { - pub(crate) struct EhFrameFinder(usize /* eh_frame */); - pub(crate) static mut EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder(0); - impl EhFrameFinder { - pub(crate) unsafe fn init(&mut self, eh_frame: usize) { - unsafe { - EH_FRAME_SETTINGS.0 = eh_frame; - } - } - } + pub(crate) struct EhFrameFinder; + pub(crate) static mut EH_FRAME_ADDRESS: usize = 0; + pub(crate) static EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder; + unsafe impl unwind::EhFrameFinder for EhFrameFinder { fn find(&self, _pc: usize) -> Option { - Some(unwind::FrameInfo { - text_base: None, - kind: unwind::FrameInfoKind::EhFrame(self.0), - }) + if unsafe { EH_FRAME_ADDRESS == 0 } { + None + } else { + Some(unwind::FrameInfo { + text_base: None, + kind: unwind::FrameInfoKind::EhFrame(unsafe { EH_FRAME_ADDRESS }), + }) + } } } } @@ -41,12 +47,21 @@ mod c_compat { } #[no_mangle] - pub extern "C" fn _start(eh_frame: usize) { + pub extern "C" fn _start(eh_frame: usize, params_address: usize) { #[cfg(feature = "panic_unwind")] - unsafe { - super::eh_unwinding::EH_FRAME_SETTINGS.init(eh_frame); + { + unsafe { super::eh_unwinding::EH_FRAME_ADDRESS = eh_frame }; unwind::set_custom_eh_frame_finder(&super::eh_unwinding::EH_FRAME_SETTINGS).ok(); } + + if params_address != 0 { + let params_address = crate::ptr::with_exposed_provenance_mut::(params_address); + if unsafe { + super::params::ApplicationParameters::new_from_ptr(params_address).is_some() + } { + super::PARAMS_ADDRESS.store(params_address, core::sync::atomic::Ordering::Relaxed); + } + } exit(unsafe { main() }); } @@ -116,44 +131,103 @@ pub fn current_exe() -> io::Result { unsupported() } -pub struct Env(!); +pub(crate) fn get_application_parameters() -> Option { + let params_address = PARAMS_ADDRESS.load(Ordering::Relaxed); + unsafe { params::ApplicationParameters::new_from_ptr(params_address) } +} + +// ---------- Environment handling ---------- // +static ENV: AtomicUsize = AtomicUsize::new(0); +static ENV_INIT: Once = Once::new(); +type EnvStore = Mutex>; + +fn get_env_store() -> &'static EnvStore { + ENV_INIT.call_once(|| { + let env_store = EnvStore::default(); + if let Some(params) = get_application_parameters() { + for param in params { + if let Ok(envs) = params::EnvironmentBlock::try_from(¶m) { + let mut env_store = env_store.lock().unwrap(); + for env in envs { + env_store.insert(env.key.into(), env.value.into()); + } + break; + } + } + } + ENV.store(Box::into_raw(Box::new(env_store)) as _, Ordering::Relaxed) + }); + unsafe { &*core::ptr::with_exposed_provenance::(ENV.load(Ordering::Relaxed)) } +} + +pub struct Env { + iter: vec::IntoIter<(OsString, OsString)>, +} + +// FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when ::fmt matches ::fmt. +pub struct EnvStrDebug<'a> { + slice: &'a [(OsString, OsString)], +} + +impl fmt::Debug for EnvStrDebug<'_> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let Self { slice } = self; + f.debug_list() + .entries(slice.iter().map(|(a, b)| (a.to_str().unwrap(), b.to_str().unwrap()))) + .finish() + } +} impl Env { // FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when ::fmt matches ::fmt. pub fn str_debug(&self) -> impl fmt::Debug + '_ { - let Self(inner) = self; - match *inner {} + let Self { iter } = self; + EnvStrDebug { slice: iter.as_slice() } } } impl fmt::Debug for Env { - fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result { - let Self(inner) = self; - match *inner {} + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let Self { iter } = self; + f.debug_list().entries(iter.as_slice()).finish() } } +impl !Send for Env {} +impl !Sync for Env {} + impl Iterator for Env { type Item = (OsString, OsString); fn next(&mut self) -> Option<(OsString, OsString)> { - self.0 + self.iter.next() + } + fn size_hint(&self) -> (usize, Option) { + self.iter.size_hint() } } pub fn env() -> Env { - panic!("not supported on this platform") + let clone_to_vec = |map: &HashMap| -> Vec<_> { + map.iter().map(|(k, v)| (k.clone(), v.clone())).collect() + }; + + let iter = clone_to_vec(&*get_env_store().lock().unwrap()).into_iter(); + Env { iter } } -pub fn getenv(_: &OsStr) -> Option { - None +pub fn getenv(k: &OsStr) -> Option { + get_env_store().lock().unwrap().get(k).cloned() } -pub unsafe fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> { - Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform")) +pub unsafe fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> { + let (k, v) = (k.to_owned(), v.to_owned()); + get_env_store().lock().unwrap().insert(k, v); + Ok(()) } -pub unsafe fn unsetenv(_: &OsStr) -> io::Result<()> { - Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform")) +pub unsafe fn unsetenv(k: &OsStr) -> io::Result<()> { + get_env_store().lock().unwrap().remove(k); + Ok(()) } pub fn temp_dir() -> PathBuf { diff --git a/library/std/src/sys/pal/xous/os/params.rs b/library/std/src/sys/pal/xous/os/params.rs new file mode 100644 index 0000000000000..0d02cf35477f9 --- /dev/null +++ b/library/std/src/sys/pal/xous/os/params.rs @@ -0,0 +1,271 @@ +/// Xous passes a pointer to the parameter block as the second argument. +/// This is used for passing flags such as environment variables. The +/// format of the argument block is: +/// +/// #[repr(C)] +/// struct BlockHeader { +/// /// Magic number that identifies this block. Must be printable ASCII. +/// magic: [u8; 4], +/// +/// /// The size of the data block. Does not include this header. May be 0. +/// size: u32, +/// +/// /// The contents of this block. Varies depending on the block type. +/// data: [u8; 0], +/// } +/// +/// There is a BlockHeader at the start that has magic `AppP`, and the data +/// that follows is the number of blocks present: +/// +/// #[repr(C)] +/// struct ApplicationParameters { +/// magic: b"AppP", +/// size: 4u32, +/// +/// /// The size of the entire application slice, in bytes, including all headers +/// length: u32, +/// +/// /// Number of application parameters present. Must be at least 1 (this block) +/// entries: (parameter_count as u32).to_bytes_le(), +/// } +/// +/// #[repr(C)] +/// struct EnvironmentBlock { +/// magic: b"EnvB", +/// +/// /// Total number of bytes, excluding this header +/// size: 2+data.len(), +/// +/// /// The number of environment variables +/// count: u16, +/// +/// /// Environment variable iteration +/// data: [u8; 0], +/// } +/// +/// Environment variables are present in an `EnvB` block. The `data` section is +/// a sequence of bytes of the form: +/// +/// (u16 /* key_len */; [0u8; key_len as usize] /* key */, +/// u16 /* val_len */ [0u8; val_len as usize]) +/// +/// #[repr(C)] +/// struct ArgumentList { +/// magic: b"ArgL", +/// +/// /// Total number of bytes, excluding this header +/// size: 2+data.len(), +/// +/// /// The number of arguments variables +/// count: u16, +/// +/// /// Argument variable iteration +/// data: [u8; 0], +/// } +/// +/// Args are just an array of strings that represent command line arguments. +/// They are a sequence of the form: +/// +/// (u16 /* val_len */ [0u8; val_len as usize]) +use core::slice; + +use crate::ffi::OsString; + +/// Magic number indicating we have an environment block +const ENV_MAGIC: [u8; 4] = *b"EnvB"; + +/// Command line arguments list +const ARGS_MAGIC: [u8; 4] = *b"ArgL"; + +/// Magic number indicating the loader has passed application parameters +const PARAMS_MAGIC: [u8; 4] = *b"AppP"; + +#[cfg(test)] +mod tests; + +pub(crate) struct ApplicationParameters { + data: &'static [u8], + offset: usize, + _entries: usize, +} + +impl ApplicationParameters { + pub(crate) unsafe fn new_from_ptr(data: *const u8) -> Option { + if data.is_null() { + return None; + } + + let magic = unsafe { core::slice::from_raw_parts(data, 4) }; + let block_length = unsafe { + u32::from_le_bytes(slice::from_raw_parts(data.add(4), 4).try_into().ok()?) as usize + }; + let data_length = unsafe { + u32::from_le_bytes(slice::from_raw_parts(data.add(8), 4).try_into().ok()?) as usize + }; + let entries = unsafe { + u32::from_le_bytes(slice::from_raw_parts(data.add(12), 4).try_into().ok()?) as usize + }; + + // Check for the main header + if data_length < 16 || magic != PARAMS_MAGIC || block_length != 8 { + return None; + } + + let data = unsafe { slice::from_raw_parts(data, data_length) }; + + Some(ApplicationParameters { data, offset: 0, _entries: entries }) + } +} + +impl Iterator for ApplicationParameters { + type Item = ApplicationParameter; + + fn next(&mut self) -> Option { + // Fetch magic, ensuring we don't run off the end + if self.offset + 4 > self.data.len() { + return None; + } + let magic = &self.data[self.offset..self.offset + 4]; + self.offset += 4; + + // Fetch header size + if self.offset + 4 > self.data.len() { + return None; + } + let size = u32::from_le_bytes(self.data[self.offset..self.offset + 4].try_into().unwrap()) + as usize; + self.offset += 4; + + // Fetch data contents + if self.offset + size > self.data.len() { + return None; + } + let data = &self.data[self.offset..self.offset + size]; + self.offset += size; + + Some(ApplicationParameter { data, magic: magic.try_into().unwrap() }) + } +} + +pub(crate) struct ApplicationParameter { + data: &'static [u8], + magic: [u8; 4], +} + +pub(crate) struct ApplicationParameterError; + +pub(crate) struct EnvironmentBlock { + _count: usize, + data: &'static [u8], + offset: usize, +} + +impl TryFrom<&ApplicationParameter> for EnvironmentBlock { + type Error = ApplicationParameterError; + + fn try_from(value: &ApplicationParameter) -> Result { + if value.data.len() < 2 || value.magic != ENV_MAGIC { + return Err(ApplicationParameterError); + } + + let count = u16::from_le_bytes(value.data[0..2].try_into().unwrap()) as usize; + + Ok(EnvironmentBlock { data: &value.data[2..], offset: 0, _count: count }) + } +} + +pub(crate) struct EnvironmentEntry { + pub key: &'static str, + pub value: &'static str, +} + +impl Iterator for EnvironmentBlock { + type Item = EnvironmentEntry; + + fn next(&mut self) -> Option { + if self.offset + 2 > self.data.len() { + return None; + } + let key_len = + u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize; + self.offset += 2; + + if self.offset + key_len > self.data.len() { + return None; + } + let key = core::str::from_utf8(&self.data[self.offset..self.offset + key_len]).ok()?; + self.offset += key_len; + + if self.offset + 2 > self.data.len() { + return None; + } + let value_len = + u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize; + self.offset += 2; + + if self.offset + value_len > self.data.len() { + return None; + } + let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?; + self.offset += value_len; + + Some(EnvironmentEntry { key, value }) + } +} + +pub(crate) struct ArgumentList { + data: &'static [u8], + _count: usize, + offset: usize, +} + +impl TryFrom<&ApplicationParameter> for ArgumentList { + type Error = ApplicationParameterError; + + fn try_from(value: &ApplicationParameter) -> Result { + if value.data.len() < 2 || value.magic != ARGS_MAGIC { + return Err(ApplicationParameterError); + } + let count = + u16::from_le_bytes(value.data[0..2].try_into().or(Err(ApplicationParameterError))?) + as usize; + Ok(ArgumentList { data: &value.data[2..], _count: count, offset: 0 }) + } +} + +pub(crate) struct ArgumentEntry { + value: &'static str, +} + +impl Into<&str> for ArgumentEntry { + fn into(self) -> &'static str { + self.value + } +} + +impl Into for ArgumentEntry { + fn into(self) -> OsString { + self.value.into() + } +} + +impl Iterator for ArgumentList { + type Item = ArgumentEntry; + + fn next(&mut self) -> Option { + if self.offset + 2 > self.data.len() { + return None; + } + let value_len = + u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize; + self.offset += 2; + + if self.offset + value_len > self.data.len() { + return None; + } + let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?; + self.offset += value_len; + + Some(ArgumentEntry { value }) + } +} diff --git a/library/std/src/sys/pal/xous/os/params/tests.rs b/library/std/src/sys/pal/xous/os/params/tests.rs new file mode 100644 index 0000000000000..0ef04ee30919f --- /dev/null +++ b/library/std/src/sys/pal/xous/os/params/tests.rs @@ -0,0 +1,75 @@ +use super::*; +use crate::collections::HashMap; +use crate::io::Write; + +fn create_args_test() -> std::io::Result> { + let mut sample_data = vec![]; + let mut h = HashMap::new(); + + h.insert("foo", "bar"); + h.insert("baz", "qux"); + h.insert("some", "val"); + + // Magic number + sample_data.write_all(&PARAMS_MAGIC)?; + // Size of the AppP block + sample_data.write_all(&4u32.to_le_bytes())?; + // Number of blocks + sample_data.write_all(&2u32.to_le_bytes())?; + + // Magic number + sample_data.write_all(&ENV_MAGIC)?; + let mut data = vec![]; + for (key, value) in h.iter() { + data.extend_from_slice(&(key.len() as u16).to_le_bytes()); + data.extend_from_slice(key.as_bytes()); + data.extend_from_slice(&(value.len() as u16).to_le_bytes()); + data.extend_from_slice(value.as_bytes()); + } + // Size of the EnvB block + sample_data.write_all(&(data.len() as u32 + 2).to_le_bytes())?; + + // Number of environment variables + sample_data.write_all(&(h.len() as u16).to_le_bytes())?; + + // Environment variables + sample_data.write_all(&data)?; + + // Write command line arguments + let args = vec!["some", "command", "line variable", "entries"]; + sample_data.write_all(&ARGS_MAGIC)?; + let mut args_size = 0; + for entry in args.iter() { + args_size += entry.len() + 2; + } + sample_data.write_all(&(args_size as u32 + 2).to_le_bytes())?; + sample_data.write_all(&(args.len() as u16).to_le_bytes())?; + for entry in args { + sample_data.write_all(&(entry.len() as u16).to_le_bytes())?; + sample_data.write_all(entry.as_bytes())?; + } + + Ok(sample_data) +} + +#[test] +fn basic_arg_parsing() { + let arg_data = create_args_test().expect("couldn't create test data"); + for byte in &arg_data { + print!("{:02x} ", byte); + } + println!(); + + let args = ApplicationParameters::new(&arg_data).expect("Unable to parse arguments"); + for arg in args { + if let Ok(env) = EnvironmentBlock::try_from(&arg) { + for env in env { + println!("{}={}", env.key, env.value); + } + } else if let Ok(args) = ArgumentList::try_from(&arg) { + for arg in args { + println!("Arg: {}", arg.value); + } + } + } +}