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Merged
JohnAZoidberg merged 3 commits into from
May 19, 2025
Merged

MEC detection: Fail if permission denied #154

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184f89b
Also require root before initializing MEC portio
JohnAZoidberg May 18, 2025
056ec31
mec init: Fail if ioperm didn't succeed
JohnAZoidberg May 18, 2025
42c816e
portio: Don't segfault if ioperm failed
JohnAZoidberg May 18, 2025
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21 changes: 13 additions & 8 deletions framework_lib/src/chromium_ec/portio.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -90,14 +90,6 @@ fn init() -> bool {
Initialized::NotYet => {}
}

// First try on MEC
portio_mec::init();
let ec_id = portio_mec::transfer_read(MEC_MEMMAP_OFFSET + EC_MEMMAP_ID, 2);
if ec_id[0] == b'E' && ec_id[1] == b'C' {
*init = Initialized::SucceededMec;
return true;
}

// In Linux userspace has to first request access to ioports
// TODO: Close these again after we're done
#[cfg(target_os = "linux")]
Expand All @@ -106,12 +98,25 @@ fn init() -> bool {
*init = Initialized::Failed;
return false;
}

// First try on MEC
if !portio_mec::init() {
*init = Initialized::Failed;
return false;
}
let ec_id = portio_mec::transfer_read(MEC_MEMMAP_OFFSET + EC_MEMMAP_ID, 2);
if ec_id[0] == b'E' && ec_id[1] == b'C' {
*init = Initialized::SucceededMec;
return true;
}

#[cfg(target_os = "linux")]
unsafe {
// 8 for request/response header, 0xFF for response
let res = ioperm(EC_LPC_ADDR_HOST_ARGS as u64, 8 + 0xFF, 1);
if res != 0 {
error!("ioperm failed. portio driver is likely block by Linux kernel lockdown mode");
*init = Initialized::Failed;
return false;
}

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14 changes: 11 additions & 3 deletions framework_lib/src/chromium_ec/portio_mec.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -22,12 +22,20 @@ const _MEC_LPC_DATA_REGISTER1: u16 = 0x0805;
const MEC_LPC_DATA_REGISTER2: u16 = 0x0806;
const _MEC_LPC_DATA_REGISTER3: u16 = 0x0807;

pub fn init() {
pub fn init() -> bool {
#[cfg(target_os = "linux")]
unsafe {
ioperm(EC_LPC_ADDR_HOST_DATA as u64, 8, 1);
ioperm(MEC_LPC_ADDRESS_REGISTER0 as u64, 10, 1);
println!("Init MEC");
let res = ioperm(EC_LPC_ADDR_HOST_DATA as u64, 8, 1);
if res != 0 {
error!("ioperm failed. portio driver is likely block by Linux kernel lockdown mode");
return false;
}
let res = ioperm(MEC_LPC_ADDRESS_REGISTER0 as u64, 10, 1);
assert_eq!(res, 0);
}

true
}

// TODO: Create a wrapper
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