Esp wifi/fix wifi logs (#2117)

* Fix `wifi-logs` feature

* Some clarifications in the esp-wifi migration guide

* CHANGELOG.md

* Review comments

* Check more features

esp-wifi/CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - esp-wifi now allocates memory from the global allocator provided by `esp-alloc` (#2099)
 
 ### Fixed
+- Feature `wifi-logs` doesn't break the build anymore (#2117)
 
 ### Removed
 

esp-wifi/MIGRATING-0.9.md

@@ -60,3 +60,31 @@ You now need to have a global allocator provided by `esp-alloc` providing alloca
 
     // ...
 ```
+
+The size of the heap depends on what you are going to use esp-wifi for and if you are using the heap for your own allocations or not.
+
+E.g. when using `coex` you need around 92k. If not using `coex`, going lower than 72k you will observe some failed allocations but it might still work. Going even lower will make things fail.
+
+### Using your own allocator
+
+You can also use your own allocator instead of using `esp-alloc`. To do that you need to opt-out of the default feature `esp-alloc` and provide two functions:
+
+```rust
+#[no_mangle]
+pub extern "C" fn esp_wifi_free_internal_heap() -> usize {
+    // return size of free allocatable RAM
+}
+
+#[no_mangle]
+pub extern "C" fn esp_wifi_allocate_from_internal_ram(size: usize) -> *mut u8 {
+    // allocate memory of size `size` from internal memory
+    unsafe {
+        core::alloc::alloc(
+            esp_alloc::MemoryCapability::Internal.into(),
+            core::alloc::Layout::from_size_align_unchecked(size, 4),
+        )
+    }
+}
+```
+
+It's important to allocate from internal memory (i.e. not PSRAM)

esp-wifi/src/compat/syslog.rs

@@ -6,15 +6,19 @@ pub unsafe extern "C" fn syslog(_priority: u32, _format: *const u8, _args: VaLis
     cfg_if::cfg_if! {
         if #[cfg(any(target_arch = "riscv32", all(target_arch = "xtensa", xtensa_has_vaarg)))]
         {
+            extern "C" {
+                fn vsnprintf(buffer: *mut u8, len: usize, fmt: *const u8, args: VaListImpl);
+            }
+
             let mut buf = [0u8; 512];
             vsnprintf(&mut buf as *mut u8, 512, _format, _args);
-            let res_str = str_from_c(&buf as *const u8);
-            info!("{}", res_str);
+            let res_str = core::ffi::CStr::from_ptr(&buf as *const _ as *const i8);
+            info!("{}", res_str.to_str().unwrap());
         }
         else
         {
-            let res_str = str_from_c(_format);
-            info!("{}", res_str);
+            let res_str = core::ffi::CStr::from_ptr(_format as *const i8);
+            info!("{}", res_str.to_str().unwrap());
         }
     }
 }

esp-wifi/src/wifi/mod.rs

@@ -2044,6 +2044,7 @@ impl PromiscuousPkt<'_> {
 }
 
 #[cfg(feature = "sniffer")]
+#[allow(clippy::type_complexity)]
 static SNIFFER_CB: Mutex<RefCell<Option<fn(PromiscuousPkt)>>> = Mutex::new(RefCell::new(None));
 
 #[cfg(feature = "sniffer")]

esp-wifi/src/wifi/os_adapter.rs

@@ -1449,7 +1449,7 @@ pub unsafe extern "C" fn log_write(
     format: *const crate::binary::c_types::c_char,
     args: ...
 ) {
-    let args = core::mem::transmute(args);
+    let args = core::mem::transmute::<core::ffi::VaListImpl<'_>, core::ffi::VaListImpl<'_>>(args);
     crate::compat::syslog::syslog(level, format as *const u8, args);
 }
 
@@ -1477,6 +1477,9 @@ pub unsafe extern "C" fn log_writev(
     format: *const crate::binary::c_types::c_char,
     args: esp_wifi_sys::include::va_list,
 ) {
+    // annotations on transmute here would require different types for RISC-V and
+    // Xtensa - so let's allow `missing_transmute_annotations` in this case
+    #[allow(clippy::missing_transmute_annotations)]
     let args = core::mem::transmute(args);
     crate::compat::syslog::syslog(level, format as *const u8, args);
 }

xtask/src/main.rs

@@ -652,11 +652,12 @@ fn lint_packages(workspace: &Path, args: LintPackagesArgs) -> Result<()> {
                 }
 
                 Package::EspWifi => {
-                    let mut features = format!("--features={chip},async,ps-min-modem,defmt");
+                    let mut features = format!(
+                        "--features={chip},async,ps-min-modem,defmt,dump-packets,wifi-logs"
+                    );
 
                     if device.contains("wifi") {
-                        features
-                            .push_str(",wifi-default,esp-now,embedded-svc,embassy-net,dump-packets")
+                        features.push_str(",wifi-default,esp-now,embedded-svc,embassy-net,sniffer")
                     }
                     if device.contains("bt") {
                         features.push_str(",ble")