feat(core): add `alloc` support for Miniscript

### core/embed/projects/firmware/Cargo.toml
@@ -40,7 +40,7 @@ frozen = ["upymod/frozen"]
 log_stack_usage = ["upymod/log_stack_usage"]
 memperf = ["upymod/memperf"]
 micropy_enable_source_lines = ["upymod/enable_source_lines"]
-miniscript = ["trezor_lib/miniscript", "upymod/miniscript", "ward"]
+miniscript = ["trezor_lib/miniscript", "upymod/miniscript", "tracked_allocator", "ward"]
 n1w1 = ["upymod/n1w1"]
 optiga_testing = ["sec/optiga_testing"]
 production = ["io/production"]
@@ -173,3 +173,4 @@ default = [
 mcu_stm32f4 = ["mcu_stm32"]
 mcu_stm32u5 = ["sec/trustzone", "mcu_stm32"]
 mcu_stm32 = []
+tracked_allocator = ["trezor_lib/tracked_allocator", "upymod/tracked_allocator"]

### core/embed/projects/firmware/src/stm32/mpconfigport.h
@@ -42,6 +42,7 @@
 #define MICROPY_ENABLE_PYSTACK      (1)
 #define MICROPY_LOADED_MODULES_DICT_SIZE (160)
 #define MICROPY_MAIN_DICT_SIZE      (8)
+#define MICROPY_TRACKED_ALLOC       (USE_TRACKED_ALLOCATOR)
 
 // emitters
 #define MICROPY_PERSISTENT_CODE_LOAD (0)

### core/embed/projects/firmware/src/unix/mpconfigport.h
@@ -47,6 +47,7 @@
 #define MICROPY_ENABLE_PYSTACK      (1)
 #define MICROPY_LOADED_MODULES_DICT_SIZE (160)
 #define MICROPY_MAIN_DICT_SIZE      (8)
+#define MICROPY_TRACKED_ALLOC       (USE_TRACKED_ALLOCATOR)
 
 // emitters
 #define MICROPY_PERSISTENT_CODE_LOAD (0)

### core/embed/rust/Cargo.toml
@@ -95,6 +95,7 @@ telemetry = []
 thp = ["crypto/thp", "dep:trezor-thp", "dep:zeroize"]
 touch = []
 touch_wakeup = []
+tracked_allocator = []
 translations = ["crypto"]
 tropic = []
 ui_antialiasing = []

### core/embed/rust/build.rs
@@ -99,6 +99,8 @@ fn generate_micropython_bindings(lib: &mut CLibrary) -> Result<()> {
             .allowlist_function("gc_alloc")
             .allowlist_function("gc_free")
             .allowlist_var("GC_ALLOC_FLAG_HAS_FINALISER")
+            .allowlist_function("m_tracked_calloc")
+            .allowlist_function("m_tracked_free")
             // iter
             .allowlist_type("mp_obj_iter_buf_t")
             .allowlist_function("mp_getiter")

### core/embed/rust/src/allocator.rs
@@ -0,0 +1,4 @@
+use crate::micropython::tracked_allocator::TrackedAllocator;
+
+#[global_allocator]
+static ALLOCATOR: TrackedAllocator = TrackedAllocator;

### core/embed/rust/src/lib.rs
@@ -11,6 +11,7 @@
 #![allow(dead_code)]
 #![feature(const_trait_impl)]
 #![feature(custom_test_frameworks)]
+#![feature(pointer_is_aligned_to)]
 #![no_main]
 #![reexport_test_harness_main = "test_main"]
 #![cfg_attr(
@@ -29,6 +30,9 @@ extern crate num_derive;
 #[macro_use]
 mod macros;
 
+#[cfg(all(feature = "tracked_allocator", feature = "micropython"))]
+mod allocator;
+
 mod align;
 #[cfg(feature = "debug")]
 mod coverage;

### core/embed/rust/src/micropython/mod.rs
@@ -30,6 +30,9 @@ pub use obj::Obj;
 #[cfg(feature = "miniscript")]
 mod miniscript;
 
+#[cfg(feature = "tracked_allocator")]
+pub mod tracked_allocator;
+
 #[cfg(feature = "dbg_console")]
 pub mod logging;
 

### core/embed/rust/src/micropython/tracked_allocator.rs
@@ -0,0 +1,53 @@
+use core::alloc::{GlobalAlloc, Layout};
+#[cfg(feature = "debug")]
+use core::sync::atomic::{AtomicUsize, Ordering};
+
+use cty::c_void;
+
+use super::ffi;
+
+pub struct TrackedAllocator;
+
+#[cfg(feature = "debug")]
+static TOTAL: AtomicUsize = AtomicUsize::new(0);
+
+// TODO: allow allocations only in an explicit scope?
+
+unsafe impl GlobalAlloc for TrackedAllocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        let size = layout.size();
+        // SAFETY:
+        //  - Unfortunately we cannot respect `layout.align()` as MicroPython GC does
+        //    not support custom alignment.
+        //  - `raw` is guaranteed to stay valid as long as `m_tracked_free()` is not
+        //    called.
+        // EXCEPTION: Returns null instead of raising.
+        let raw: *mut c_void = unsafe { ffi::m_tracked_calloc(1, size) };
+        if !raw.is_null() {
+            #[cfg(feature = "debug")]
+            log::trace!(
+                "{:?} = {} : +{}",
+                raw,
+                TOTAL.fetch_add(size, Ordering::Relaxed),
+                size
+            );
+            ensure!(raw.is_aligned_to(layout.align()), "Unaligned allocation");
+        }
+        raw as _
+    }
+    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+        let raw = ptr as *mut c_void;
+        #[cfg(feature = "debug")]
+        {
+            let size = _layout.size();
+            log::trace!(
+                "{:?} = {} : -{}",
+                raw,
+                TOTAL.fetch_sub(size, Ordering::Relaxed),
+                size
+            );
+        }
+        // SAFETY: We are the sole owner of the allocated value.
+        unsafe { ffi::m_tracked_free(raw) };
+    }
+}

### core/embed/upymod/Cargo.toml
@@ -61,6 +61,7 @@ pyopt = []
 rgb_led = ["io/rgb_led"]
 sd_card = ["io/sd_card"]
 serial_number = []
+tracked_allocator = []
 telemetry = ["sec/telemetry"]
 thp = []
 touch = ["io/touch"]

### core/embed/upymod/build.rs
@@ -72,6 +72,10 @@ fn main() -> Result<()> {
             lib.add_define("USE_MINISCRIPT", Some("1"));
         }
 
+        if cfg!(feature = "tracked_allocator") {
+            lib.add_define("USE_TRACKED_ALLOCATOR", Some("1"));
+        }
+
         if cfg!(feature = "n1w1") {
             lib.add_define("USE_N1W1", Some("1"));
         }