[avb] Move PartitionName and util methods to separate modules
This is a refactoring. There's no behavior change in this cl.
Bug: 256148034
Test: m pvmfw_img && atest libpvmfw_avb.integration_test
Change-Id: I3926076293cead03db0ca3409fc82fc120cb80ce
diff --git a/pvmfw/avb/src/partition.rs b/pvmfw/avb/src/partition.rs
new file mode 100644
index 0000000..82d89f8
--- /dev/null
+++ b/pvmfw/avb/src/partition.rs
@@ -0,0 +1,86 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Struct and functions relating to well-known partition names.
+
+use crate::error::AvbIOError;
+use crate::utils::is_not_null;
+use core::ffi::{c_char, CStr};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) enum PartitionName {
+ Kernel,
+ InitrdNormal,
+ InitrdDebug,
+}
+
+impl PartitionName {
+ const KERNEL_PARTITION_NAME: &[u8] = b"boot\0";
+ const INITRD_NORMAL_PARTITION_NAME: &[u8] = b"initrd_normal\0";
+ const INITRD_DEBUG_PARTITION_NAME: &[u8] = b"initrd_debug\0";
+
+ pub(crate) fn as_cstr(&self) -> &CStr {
+ CStr::from_bytes_with_nul(self.as_bytes()).unwrap()
+ }
+
+ fn as_non_null_terminated_bytes(&self) -> &[u8] {
+ let partition_name = self.as_bytes();
+ &partition_name[..partition_name.len() - 1]
+ }
+
+ fn as_bytes(&self) -> &[u8] {
+ match self {
+ Self::Kernel => Self::KERNEL_PARTITION_NAME,
+ Self::InitrdNormal => Self::INITRD_NORMAL_PARTITION_NAME,
+ Self::InitrdDebug => Self::INITRD_DEBUG_PARTITION_NAME,
+ }
+ }
+}
+
+impl TryFrom<*const c_char> for PartitionName {
+ type Error = AvbIOError;
+
+ fn try_from(partition_name: *const c_char) -> Result<Self, Self::Error> {
+ is_not_null(partition_name)?;
+ // SAFETY: It is safe as the raw pointer `partition_name` is a nonnull pointer.
+ let partition_name = unsafe { CStr::from_ptr(partition_name) };
+ partition_name.try_into()
+ }
+}
+
+impl TryFrom<&CStr> for PartitionName {
+ type Error = AvbIOError;
+
+ fn try_from(partition_name: &CStr) -> Result<Self, Self::Error> {
+ match partition_name.to_bytes_with_nul() {
+ Self::KERNEL_PARTITION_NAME => Ok(Self::Kernel),
+ Self::INITRD_NORMAL_PARTITION_NAME => Ok(Self::InitrdNormal),
+ Self::INITRD_DEBUG_PARTITION_NAME => Ok(Self::InitrdDebug),
+ _ => Err(AvbIOError::NoSuchPartition),
+ }
+ }
+}
+
+impl TryFrom<&[u8]> for PartitionName {
+ type Error = AvbIOError;
+
+ fn try_from(non_null_terminated_name: &[u8]) -> Result<Self, Self::Error> {
+ match non_null_terminated_name {
+ x if x == Self::Kernel.as_non_null_terminated_bytes() => Ok(Self::Kernel),
+ x if x == Self::InitrdNormal.as_non_null_terminated_bytes() => Ok(Self::InitrdNormal),
+ x if x == Self::InitrdDebug.as_non_null_terminated_bytes() => Ok(Self::InitrdDebug),
+ _ => Err(AvbIOError::NoSuchPartition),
+ }
+ }
+}