feat(core): Add Rust bindings to MicroPython and trezorhal

core: Remove dangling module decls

core: Use new Cargo feature resolver, use external MacOS debug info

core: Rust docs improvements

core: Upgrade bindgen

core: Add test target to Rust

ci: build rust sources

build(core): .ARM.exidx.text.__aeabi_ui2f in t1 firmware size

It's an unwind table for softfloat function inserted by rustc, probably
can be removed to save 8 bytes:
/~https://github.com/rust-embedded/cortex-m-rt/blob/599c58db70c5dd4eb1dfb92e1dad7c80ed848937/link.x.in#L175-L182

scons: Remove dead code

core: Move Rust target to build/rust

core: Replace extern with a FFI version

core: Add some explanatory Rust comments

core: Use correct path for the Rust lib

core: Remove Buffer::as_mut()

Mutable buffer access needs MP_BUFFER_WRITE flag. TBD in the Protobuf PR.

core: Improve docs for micropython::Buffer

core: Minor Rust docs changes

core: Rewrite trezor_obj_get_ll_checked

core: Fix incorrect doc comment

core: Remove cc from deps

fixup! core: Rewrite trezor_obj_get_ll_checked

core: update safety comments

ci/shell.nix

@@ -2,25 +2,35 @@
 , hardwareTest ? false
  }:
 
-# the last successful build of nixpkgs-unstable as of 2021-03-25
-with import (builtins.fetchTarball {
-  url = "/~https://github.com/NixOS/nixpkgs/archive/c0e881852006b132236cbf0301bd1939bb50867e.tar.gz";
-  sha256 = "0fy7z7yxk5n7yslsvx5cyc6h21qwi4bhxf3awhirniszlbvaazy2";
-})
-{ };
-
 let
-  moneroTests = fetchurl {
+  mozillaOverlay = import (builtins.fetchTarball {
+    url = "/~https://github.com/mozilla/nixpkgs-mozilla/archive/8c007b60731c07dd7a052cce508de3bb1ae849b4.tar.gz";
+    sha256 = "1zybp62zz0h077zm2zmqs2wcg3whg6jqaah9hcl1gv4x8af4zhs6";
+  });
+  # the last successful build of nixpkgs-unstable as of 2021-03-25
+  nixpkgs = import (builtins.fetchTarball {
+    url = "/~https://github.com/NixOS/nixpkgs/archive/c0e881852006b132236cbf0301bd1939bb50867e.tar.gz";
+    sha256 = "0fy7z7yxk5n7yslsvx5cyc6h21qwi4bhxf3awhirniszlbvaazy2";
+  }) { overlays = [ mozillaOverlay ]; };
+  moneroTests = nixpkgs.fetchurl {
     url = "/~https://github.com/ph4r05/monero/releases/download/v0.17.1.9-tests/trezor_tests";
     sha256 = "410bc4ff2ff1edc65e17f15b549bd1bf8a3776cf67abdea86aed52cf4bce8d9d";
   };
-  moneroTestsPatched = runCommandCC "monero_trezor_tests" {} ''
+  moneroTestsPatched = nixpkgs.runCommandCC "monero_trezor_tests" {} ''
     cp ${moneroTests} $out
     chmod +wx $out
-    ${patchelf}/bin/patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" "$out"
+    ${nixpkgs.patchelf}/bin/patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" "$out"
     chmod -w $out
   '';
+  rustNightly = (nixpkgs.rustChannelOf { date = "2021-03-29"; channel = "nightly"; }).rust.override {
+    targets = [
+      "x86_64-unknown-linux-gnu" # emulator
+      "thumbv7em-none-eabihf"    # TT
+      "thumbv7em-none-eabi"      # T1
+    ];
+  };
 in
+with nixpkgs;
 stdenv.mkDerivation ({
   name = "trezor-firmware-env";
   buildInputs = lib.optionals fullDeps [
@@ -38,6 +48,7 @@ stdenv.mkDerivation ({
     bash
     check
     clang-tools
+    clang
     editorconfig-checker
     gcc
     gcc-arm-embedded
@@ -52,6 +63,8 @@ stdenv.mkDerivation ({
     pkgconfig
     poetry
     protobuf3_6
+    rustfmt
+    rustNightly
     wget
     zlib
   ] ++ lib.optionals (!stdenv.isDarwin) [
@@ -80,6 +93,8 @@ stdenv.mkDerivation ({
   # Fix bdist-wheel problem by setting source date epoch to a more recent date
   SOURCE_DATE_EPOCH = 1600000000;
 
+  # Used by rust bindgen
+  LIBCLANG_PATH = "${llvmPackages.libclang}/lib";
 } // (lib.optionalAttrs fullDeps) {
   TREZOR_MONERO_TESTS_PATH = moneroTestsPatched;
 })

core/.changelog.d/1540.added

@@ -0,0 +1 @@
+Rust FFI for MicroPython.

core/Makefile

@@ -12,6 +12,7 @@ PRODTEST_BUILD_DIR    = $(BUILD_DIR)/prodtest
 REFLASH_BUILD_DIR     = $(BUILD_DIR)/reflash
 FIRMWARE_BUILD_DIR    = $(BUILD_DIR)/firmware
 UNIX_BUILD_DIR        = $(BUILD_DIR)/unix
+RUST_BUILD_DIR        = $(BUILD_DIR)/rust
 
 UNAME_S := $(shell uname -s)
 UNIX_PORT_OPTS ?=
@@ -179,10 +180,10 @@ clean_reflash: ## clean reflash build
 	rm -rf $(REFLASH_BUILD_DIR)
 
 clean_firmware: ## clean firmware build
-	rm -rf $(FIRMWARE_BUILD_DIR)
+	rm -rf $(FIRMWARE_BUILD_DIR) $(RUST_BUILD_DIR)
 
 clean_unix: ## clean unix build
-	rm -rf $(UNIX_BUILD_DIR)
+	rm -rf $(UNIX_BUILD_DIR) $(RUST_BUILD_DIR)
 
 clean_cross: ## clean mpy-cross build
 	$(MAKE) -C vendor/micropython/mpy-cross clean $(CROSS_PORT_OPTS)

core/SConscript.firmware

@@ -1,4 +1,5 @@
 # pylint: disable=E0602
+# fmt: off
 
 import os
 
@@ -49,6 +50,7 @@ CPPDEFINES_MOD += [
     ('USE_EOS', '1' if EVERYTHING else '0'),
 ]
 SOURCE_MOD += [
+    'embed/extmod/trezorobj.c',
     'embed/extmod/modtrezorcrypto/crc.c',
     'embed/extmod/modtrezorcrypto/modtrezorcrypto.c',
     'embed/extmod/modtrezorcrypto/rand.c',
@@ -394,11 +396,13 @@ if TREZOR_MODEL == 'T':
     CPU_CCFLAGS = '-mthumb -mcpu=cortex-m4 -mfloat-abi=hard -mfpu=fpv4-sp-d16 -mtune=cortex-m4 '
     CPU_MODEL   = 'STM32F427xx'
     LD_VARIANT  = '_zkp' if FEATURE_FLAGS["SECP256K1_ZKP"] else ''
+    RUST_TARGET = 'thumbv7em-none-eabihf'
 elif TREZOR_MODEL == '1':
     CPU_ASFLAGS = '-mthumb -mcpu=cortex-m3 -mfloat-abi=soft'
     CPU_CCFLAGS = '-mthumb -mtune=cortex-m3 -mcpu=cortex-m3 -mfloat-abi=soft '
     CPU_MODEL   = 'STM32F405xx'
     LD_VARIANT  = '' if EVERYTHING else '_min'
+    RUST_TARGET = 'thumbv7em-none-eabi'
 else:
     raise ValueError('Unknown Trezor model')
 
@@ -416,6 +420,7 @@ env.Replace(
     LINKFLAGS='-T embed/firmware/memory_${TREZOR_MODEL}%s.ld -Wl,--gc-sections -Wl,-Map=build/firmware/firmware.map -Wl,--warn-common' % LD_VARIANT,
     CPPPATH=[
         '.',
+        'embed/rust',
         'embed/firmware',
         'embed/trezorhal',
         'embed/extmod/modtrezorui',
@@ -616,6 +621,33 @@ if FEATURE_FLAGS["SECP256K1_ZKP"]:
         action='cd ${SOURCE.dir}; ./gen_context',
     )
 
+#
+# Rust library
+#
+
+RUST_PROFILE = 'release'
+RUST_LIB = 'trezor_lib'
+RUST_LIBDIR = f'build/rust/{RUST_TARGET}/{RUST_PROFILE}'
+RUST_LIBPATH = f'{RUST_LIBDIR}/lib{RUST_LIB}.a'
+
+def cargo_build():
+    # Determine the profile build flags.
+    if RUST_PROFILE == 'release':
+        profile = '--release'
+    else:
+        profile = ''
+    return f'cd embed/rust; cargo build {profile} --target={RUST_TARGET}'
+
+rust = env.Command(
+    target=RUST_LIBPATH,
+    source='',
+    action=cargo_build(), )
+
+env.Depends(rust, qstr_generated)
+
+env.Append(LINKFLAGS=f' -L{RUST_LIBDIR}')
+env.Append(LINKFLAGS=f' -l{RUST_LIB}')
+
 #
 # Program objects
 #
@@ -658,9 +690,11 @@ program_elf = env.Command(
     target='firmware.elf',
     source=obj_program,
     action=
-    '$LINK -o $TARGET $CCFLAGS $CFLAGS $LINKFLAGS $SOURCES -lc_nano -lm -lgcc',
+    '$LINK -o $TARGET $CCFLAGS $CFLAGS $SOURCES $LINKFLAGS -lc_nano -lm -lgcc',
 )
 
+env.Depends(program_elf, rust)
+
 if TREZOR_MODEL == 'T':
     action_bin=[
         '$OBJCOPY -O binary -j .vendorheader -j .header -j .flash -j .data --pad-to 0x08100000 $SOURCE ${TARGET}.p1',

core/SConscript.unix

@@ -1,4 +1,5 @@
 # pylint: disable=E0602
+# fmt: off
 
 import os
 
@@ -48,6 +49,7 @@ CPPDEFINES_MOD += [
     ('USE_EOS', '1' if EVERYTHING else '0'),
 ]
 SOURCE_MOD += [
+    'embed/extmod/trezorobj.c',
     'embed/extmod/modtrezorcrypto/modtrezorcrypto.c',
     'embed/extmod/modtrezorcrypto/crc.c',
     'vendor/trezor-crypto/address.c',
@@ -367,6 +369,7 @@ env.Replace(
     LIBS=['m'],
     CPPPATH=[
         '.',
+        'embed/rust',
         'embed/unix',
         'embed/extmod/modtrezorui',
         'vendor/micropython',
@@ -567,6 +570,33 @@ if FEATURE_FLAGS["SECP256K1_ZKP"]:
         action='cd ${SOURCE.dir}; ./gen_context',
     )
 
+#
+# Rust library
+#
+
+RUST_PROFILE = 'release'
+RUST_LIB = 'trezor_lib'
+RUST_LIBDIR = f'build/rust/{RUST_PROFILE}'
+RUST_LIBPATH = f'{RUST_LIBDIR}/lib{RUST_LIB}.a'
+
+def cargo_build():
+    # Determine the profile build flags.
+    if RUST_PROFILE == 'release':
+        profile = '--release'
+    else:
+        profile = ''
+    return f'cd embed/rust; cargo build {profile}'
+
+rust = env.Command(
+    target=RUST_LIBPATH,
+    source='',
+    action=cargo_build(), )
+
+env.Depends(rust, qstr_generated)
+
+env.Append(LINKFLAGS=f'-L{RUST_LIBDIR}')
+env.Append(LINKFLAGS=f'-l{RUST_LIB}')
+
 #
 # Program objects
 #
@@ -588,3 +618,5 @@ program = env.Command(
     target='trezor-emu-core',
     source=obj_program,
     action='$CC -o $TARGET $SOURCES $_LIBDIRFLAGS $_LIBFLAGS $LINKFLAGS', )
+
+env.Depends(program, rust)

core/embed/extmod/trezorobj.c

@@ -0,0 +1,64 @@
+/*
+ * This file is part of the Trezor project, https://trezor.io/
+ *
+ * Copyright (c) SatoshiLabs
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+
+#include "memzero.h"
+#include "py/objint.h"
+
+static bool mpz_as_ll_checked(const mpz_t *i, long long *value) {
+  // Analogue of `mpz_as_int_checked` from mpz.c
+
+  unsigned long long val = 0;
+  mpz_dig_t *d = i->dig + i->len;
+
+  while (d-- > i->dig) {
+    if (val > (~0x8000000000000000 >> MPZ_DIG_SIZE)) {
+      // will overflow
+      *value = 0;
+      return false;
+    }
+    val = (val << MPZ_DIG_SIZE) | *d;
+  }
+
+  if (i->neg != 0) {
+    val = -val;
+  }
+
+  *value = val;
+  return true;
+}
+
+bool trezor_obj_get_ll_checked(mp_obj_t obj, long long *value) {
+  if (mp_obj_is_small_int(obj)) {
+    // Value is fitting in a small int range. Return it directly.
+    *value = MP_OBJ_SMALL_INT_VALUE(obj);
+    return true;
+
+  } else if (mp_obj_is_type(obj, &mp_type_int)) {
+    // Value is not fitting into small int range, but is an integer.
+    mp_obj_int_t *self = MP_OBJ_TO_PTR(obj);
+    // Try to get the long long value out of the MPZ struct.
+    return mpz_as_ll_checked(&self->mpz, value);
+  } else {
+    // Value is not integer.
+    *value = 0;
+    return false;
+  }
+}

core/embed/extmod/trezorobj.h

@@ -75,4 +75,6 @@ static inline uint8_t trezor_obj_get_uint8(mp_obj_t obj) {
   return u;
 }
 
+bool trezor_obj_get_ll_checked(mp_obj_t obj, long long *value);
+
 #endif

core/embed/firmware/memory_1.ld

@@ -26,7 +26,8 @@ sram_end = ORIGIN(SRAM) + LENGTH(SRAM);
 _ram_start = sram_start;
 _ram_end = sram_end;
 
-_codelen = SIZEOF(.flash) + SIZEOF(.data) + SIZEOF(.ARM.exidx);
+/* .ARM.exidx.text.__aeabi_ui2f is probably not needed as long as we are using panic = "abort" */
+_codelen = SIZEOF(.flash) + SIZEOF(.data) + SIZEOF(.ARM.exidx) + SIZEOF(.ARM.exidx.text.__aeabi_ui2f);
 _flash_start = ORIGIN(FLASH);
 _flash_end = ORIGIN(FLASH) + LENGTH(FLASH);
 _heap_start = ADDR(.heap);

core/embed/firmware/memory_1_min.ld

@@ -26,7 +26,8 @@ sram_end = ORIGIN(SRAM) + LENGTH(SRAM);
 _ram_start = sram_start;
 _ram_end = sram_end;
 
-_codelen = SIZEOF(.flash) + SIZEOF(.data);
+/* .ARM.exidx.text.__aeabi_ui2f is probably not needed as long as we are using panic = "abort" */
+_codelen = SIZEOF(.flash) + SIZEOF(.data) + SIZEOF(.ARM.exidx.text.__aeabi_ui2f);
 _flash_start = ORIGIN(FLASH);
 _flash_end = ORIGIN(FLASH) + LENGTH(FLASH);
 _heap_start = ADDR(.heap);

core/embed/rust/.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+target-dir = "../../build/rust"