pvmfw: refactor: Regroup config data slicing
As we need the slices covering the entries of the configuration data to
be mutable (e.g. to zero the BCC's CDIs or apply a DTBO), unify the API
so that both slices are returned through one call, to please the borrow
checked when the slices are used at the same time i.e. to avoid
error[E0499]: cannot borrow `appended` as mutable more than once at a time
Note: No functional change intended.
Bug: 249054080
Bug: 268265510
Test: atest MicrodroidHostTests
Change-Id: I53f789add85f3f1b602a7b91cce3e7dd78727eef
diff --git a/pvmfw/src/config.rs b/pvmfw/src/config.rs
index f209784..f62a580 100644
--- a/pvmfw/src/config.rs
+++ b/pvmfw/src/config.rs
@@ -216,12 +216,22 @@
}
/// Get slice containing the platform BCC.
- pub fn get_bcc_mut(&mut self) -> &mut [u8] {
- &mut self.body[self.bcc_range.clone()]
- }
+ pub fn get_entries(&mut self) -> (&mut [u8], Option<&mut [u8]>) {
+ let bcc_start = self.bcc_range.start;
+ let bcc_end = self.bcc_range.len();
+ let (_, rest) = self.body.split_at_mut(bcc_start);
+ let (bcc, rest) = rest.split_at_mut(bcc_end);
- /// Get slice containing the platform debug policy.
- pub fn get_debug_policy(&mut self) -> Option<&mut [u8]> {
- self.dp_range.as_ref().map(|r| &mut self.body[r.clone()])
+ let dp = if let Some(dp_range) = &self.dp_range {
+ let dp_start = dp_range.start.checked_sub(self.bcc_range.end).unwrap();
+ let dp_end = dp_range.len();
+ let (_, rest) = rest.split_at_mut(dp_start);
+ let (dp, _) = rest.split_at_mut(dp_end);
+ Some(dp)
+ } else {
+ None
+ };
+
+ (bcc, dp)
}
}
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index a1cd2a1..106a4ef 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -242,7 +242,7 @@
RebootReason::InvalidConfig
})?;
- let bcc_slice = appended.get_bcc_mut();
+ let (bcc_slice, debug_policy) = appended.get_entries();
debug!("Activating dynamic page table...");
// SAFETY - page_table duplicates the static mappings for everything that the Rust code is
@@ -266,7 +266,7 @@
// SAFETY - As we `?` the result, there is no risk of using a bad `slices.fdt`.
unsafe {
- handle_debug_policy(slices.fdt, appended.get_debug_policy()).map_err(|e| {
+ handle_debug_policy(slices.fdt, debug_policy).map_err(|e| {
error!("Unexpected error when handling debug policy: {e:?}");
RebootReason::from(e)
})?;
@@ -397,17 +397,10 @@
}
}
- fn get_debug_policy(&mut self) -> Option<&mut [u8]> {
+ fn get_entries(&mut self) -> (&mut [u8], Option<&mut [u8]>) {
match self {
- Self::Config(ref mut cfg) => cfg.get_debug_policy(),
- Self::LegacyBcc(_) => None,
- }
- }
-
- fn get_bcc_mut(&mut self) -> &mut [u8] {
- match self {
- Self::LegacyBcc(ref mut bcc) => bcc,
- Self::Config(ref mut cfg) => cfg.get_bcc_mut(),
+ Self::Config(ref mut cfg) => cfg.get_entries(),
+ Self::LegacyBcc(ref mut bcc) => (bcc, None),
}
}
}