Add a binding (target_is_big_endian()) to check whether target is big
endian or not. This could help user to adjust endian before calling
AddresssSpace::store() or after calling AddressSpace::load().
Add the example in the documentation of AddresssSpace::store() to help
explain how to use it.
Signed-off-by: Zhao Liu <zhao1....@intel.com>
---
rust/qemu-api/src/memory.rs | 28 +++++++++++++++++++++++++---
rust/qemu-api/wrapper.h | 1 +
2 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/rust/qemu-api/src/memory.rs b/rust/qemu-api/src/memory.rs
index 42bba23cf3f8..a8eb83c95ead 100644
--- a/rust/qemu-api/src/memory.rs
+++ b/rust/qemu-api/src/memory.rs
@@ -31,7 +31,7 @@
memory_region_init_io, section_access_allowed,
section_covers_region_addr,
section_fuzz_dma_read, section_get_host_addr, section_rust_load,
section_rust_read_continue_step, section_rust_store,
section_rust_write_continue_step,
- MEMTX_OK,
+ target_big_endian, MEMTX_OK,
},
callbacks::FnCall,
cell::Opaque,
@@ -1107,9 +1107,25 @@ pub fn read(&self, buf: &mut [u8], addr: GuestAddress)
-> Result<usize> {
/// This function is similar to `address_space_st{size}` in C side.
///
/// But it only assumes @val follows target-endian by default. So ensure
- /// the endian of `val` aligned with target, before using this method.
+ /// the endian of `val` aligned with target, before using this method. The
+ /// taget-endian can be checked with [`target_is_big_endian`].
///
/// And it assumes the memory attributes is MEMTXATTRS_UNSPECIFIED.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use qemu_api::memory::{ADDRESS_SPACE_MEMORY, target_is_big_endian};
+ ///
+ /// let addr = GuestAddress(0x123438000);
+ /// let val: u32 = 5;
+ /// let val_end = if target_is_big_endian() {
+ /// val.to_be()
+ /// } else {
+ /// val.to_le()
+ /// }
+ ///
+ /// assert!(ADDRESS_SPACE_MEMORY.store(addr, val_end).is_ok());
pub fn store<T: AtomicAccess>(&self, addr: GuestAddress, val: T) ->
Result<()> {
rcu_read_lock();
let r = self.memory().deref().store(val, addr, Ordering::Relaxed);
@@ -1122,7 +1138,8 @@ pub fn store<T: AtomicAccess>(&self, addr: GuestAddress,
val: T) -> Result<()> {
/// This function is similar to `address_space_ld{size}` in C side.
///
/// But it only support target-endian by default. The returned value is
- /// with target-endian.
+ /// with target-endian. The taget-endian can be checked with
+ /// [`target_is_big_endian`].
///
/// And it assumes the memory attributes is MEMTXATTRS_UNSPECIFIED.
pub fn load<T: AtomicAccess>(&self, addr: GuestAddress) -> Result<T> {
@@ -1147,3 +1164,8 @@ pub fn load<T: AtomicAccess>(&self, addr: GuestAddress)
-> Result<T> {
// the whole QEMU life.
&*wrapper_ptr
};
+
+pub fn target_is_big_endian() -> bool {
+ // SAFETY: the return value is boolean, so it is always valid.
+ unsafe { target_big_endian() }
+}
diff --git a/rust/qemu-api/wrapper.h b/rust/qemu-api/wrapper.h
index ce0ac8d3f550..c466b93054aa 100644
--- a/rust/qemu-api/wrapper.h
+++ b/rust/qemu-api/wrapper.h
@@ -70,3 +70,4 @@ typedef enum memory_order {
#include "system/address-spaces.h"
#include "hw/char/pl011.h"
#include "qemu/rcu.h"
+#include "qemu/target-info.h"
--
2.34.1
