runtime/rpc: fixes alignment and size problem

This reverts commit 95d024e38b.

README.md

@@ -62,7 +62,7 @@ cd ..
 
 Notes:
 
-- This is developed with Nixpkgs 20.09, and the ``nixbld.m-labs.hk`` binary substituter can also be used here (see the ARTIQ manual for the public key and instructions).
+- This is developed with Nixpkgs 21.05, and the ``nixbld.m-labs.hk`` binary substituter can also be used here (see the ARTIQ manual for the public key and instructions).
 - The impure build process is also compatible with non-Nix systems.
 - If the board is connected to the local machine, use the ``local_run.sh`` script.
 - To update ``zynq-rs``, update the cargo files as per usual for Rust projects, but also keep ``zynq-rs.nix`` in sync.
@@ -70,7 +70,7 @@ Notes:
 License
 -------
 
-Copyright (C) 2019-2020 M-Labs Limited.
+Copyright (C) 2019-2021 M-Labs Limited.
 
 ARTIQ is free software: you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License as published by

default.nix

@@ -20,7 +20,7 @@ let
       name = "firmware";
 
       src = ./src;
-      cargoSha256 = "1d84yknyizbxgsqj478339fxcyvxq9pzdv0ljrwrgmzgfynqmssj";
+      cargoSha256 = "1g1nb8jz1na1v60hq3zrpgrwnw9qz7xrnnr2lkiyhsp72bg52ssl";
 
       nativeBuildInputs = [
         pkgs.gnumake
@@ -31,6 +31,7 @@ let
       ];
       buildPhase = ''
         export XARGO_RUST_SRC="${rustPlatform.rust.rustc}/lib/rustlib/src/rust/library"
+        export CLANG_EXTRA_INCLUDE_DIR="${pkgs.llvmPackages_9.clang-unwrapped.lib}/lib/clang/9.0.1/include"
         export CARGO_HOME=$(mktemp -d cargo-home.XXX)
         make TARGET=${target} VARIANT=${variant}
       '';

shell.nix

@@ -30,6 +30,7 @@ in
     ];
 
     XARGO_RUST_SRC = "${rustPlatform.rust.rustc}/lib/rustlib/src/rust/library";
+    CLANG_EXTRA_INCLUDE_DIR = "${pkgs.llvmPackages_9.clang-unwrapped.lib}/lib/clang/9.0.1/include";
     OPENOCD_ZYNQ = "${zynq-rs}/openocd";
     SZL = "${zc706-szl}/szl.elf";
   }

src/Cargo.lock

@@ -2,9 +2,9 @@
 # It is not intended for manual editing.
 [[package]]
 name = "async-recursion"
-version = "0.3.1"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5444eec77a9ec2bfe4524139e09195862e981400c4358d3b760cae634e4c4ee"
+checksum = "d7d78656ba01f1b93024b7c3a0467f1608e4be67d725749fdcd7d2c7678fd7a2"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -31,15 +31,15 @@ checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
 [[package]]
 name = "byteorder"
-version = "1.3.4"
+version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08c48aae112d48ed9f069b33538ea9e3e90aa263cfa3d1c24309612b1f7472de"
+checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
 [[package]]
 name = "cc"
-version = "1.0.66"
+version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c0496836a84f8d0495758516b8621a622beb77c0fed418570e50764093ced48"
+checksum = "e70cc2f62c6ce1868963827bd677764c62d07c3d9a3e1fb1177ee1a9ab199eb2"
 
 [[package]]
 name = "cfg-if"
@@ -47,6 +47,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "compiler_builtins"
 version = "0.1.39"
@@ -55,10 +61,11 @@ checksum = "3748f82c7d366a0b4950257d19db685d4958d2fa27c6d164a3f069fec42b748b"
 
 [[package]]
 name = "core_io"
-version = "0.1.20200410"
+version = "0.1.20210325"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97f8932064288cc79feb4d343a399d353a6f6f001e586ece47fe518a9e8507df"
 dependencies = [
- "memchr",
+ "rustc_version",
 ]
 
 [[package]]
@@ -71,7 +78,7 @@ checksum = "0f8cb7306107e4b10e64994de6d3274bd08996a7c1322a27b86482392f96be0a"
 name = "dwarf"
 version = "0.0.0"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "compiler_builtins",
  "libc",
  "unwind",
@@ -87,9 +94,9 @@ dependencies = [
 
 [[package]]
 name = "embedded-hal"
-version = "0.2.4"
+version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa998ce59ec9765d15216393af37a58961ddcefb14c753b4816ba2191d865fcb"
+checksum = "db184d3fa27bc7a2344250394c0264144dfe0bc81a4401801dcb964b8dd172ad"
 dependencies = [
  "nb 0.1.3",
  "void",
@@ -97,9 +104,9 @@ dependencies = [
 
 [[package]]
 name = "fatfs"
-version = "0.3.4"
+version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93079df23039e52059e1f03b4c29fb0c72da2c792aad91bb2236c9fb81d3592e"
+checksum = "e18f80a87439240dac45d927fd8f8081b6f1e34c03e97271189fa8a8c2e96c8f"
 dependencies = [
  "bitflags",
  "byteorder",
@@ -109,9 +116,9 @@ dependencies = [
 
 [[package]]
 name = "futures"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b3b0c040a1fe6529d30b3c5944b280c7f0dcb2930d2c3062bca967b602583d0"
+checksum = "1adc00f486adfc9ce99f77d717836f0c5aa84965eb0b4f051f4e83f7cab53f8b"
 dependencies = [
  "futures-channel",
  "futures-core",
@@ -123,9 +130,9 @@ dependencies = [
 
 [[package]]
 name = "futures-channel"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b7109687aa4e177ef6fe84553af6280ef2778bdb7783ba44c9dc3399110fe64"
+checksum = "74ed2411805f6e4e3d9bc904c95d5d423b89b3b25dc0250aa74729de20629ff9"
 dependencies = [
  "futures-core",
  "futures-sink",
@@ -133,22 +140,23 @@ dependencies = [
 
 [[package]]
 name = "futures-core"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "847ce131b72ffb13b6109a221da9ad97a64cbe48feb1028356b836b47b8f1748"
+checksum = "af51b1b4a7fdff033703db39de8802c673eb91855f2e0d47dcf3bf2c0ef01f99"
 
 [[package]]
 name = "futures-io"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "611834ce18aaa1bd13c4b374f5d653e1027cf99b6b502584ff8c9a64413b30bb"
+checksum = "0b0e06c393068f3a6ef246c75cdca793d6a46347e75286933e5e75fd2fd11582"
 
 [[package]]
 name = "futures-macro"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77408a692f1f97bcc61dc001d752e00643408fbc922e4d634c655df50d595556"
+checksum = "c54913bae956fb8df7f4dc6fc90362aa72e69148e3f39041fbe8742d21e0ac57"
 dependencies = [
+ "autocfg",
  "proc-macro-hack",
  "proc-macro2",
  "quote",
@@ -157,27 +165,28 @@ dependencies = [
 
 [[package]]
 name = "futures-sink"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f878195a49cee50e006b02b93cf7e0a95a38ac7b776b4c4d9cc1207cd20fcb3d"
+checksum = "c0f30aaa67363d119812743aa5f33c201a7a66329f97d1a887022971feea4b53"
 
 [[package]]
 name = "futures-task"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c554eb5bf48b2426c4771ab68c6b14468b6e76cc90996f528c3338d761a4d0d"
+checksum = "bbe54a98670017f3be909561f6ad13e810d9a51f3f061b902062ca3da80799f2"
 
 [[package]]
 name = "futures-util"
-version = "0.3.8"
+version = "0.3.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d304cff4a7b99cfb7986f7d43fbe93d175e72e704a8860787cc95e9ffd85cbd2"
+checksum = "67eb846bfd58e44a8481a00049e82c43e0ccb5d61f8dc071057cb19249dd4d78"
 dependencies = [
+ "autocfg",
  "futures-core",
  "futures-macro",
  "futures-sink",
  "futures-task",
- "pin-project",
+ "pin-project-lite",
  "pin-utils",
  "proc-macro-hack",
  "proc-macro-nested",
@@ -186,7 +195,7 @@ dependencies = [
 [[package]]
 name = "libasync"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "embedded-hal",
  "libcortex_a9",
@@ -198,7 +207,7 @@ dependencies = [
 [[package]]
 name = "libboard_zynq"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "bit_field",
  "embedded-hal",
@@ -223,7 +232,7 @@ dependencies = [
 [[package]]
 name = "libconfig"
 version = "0.1.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "core_io",
  "fatfs",
@@ -234,7 +243,7 @@ dependencies = [
 [[package]]
 name = "libcortex_a9"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "bit_field",
  "libregister",
@@ -250,7 +259,7 @@ checksum = "c7d73b3f436185384286bd8098d17ec07c9a7d2388a6599f824d8502b529702a"
 [[package]]
 name = "libregister"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "bit_field",
  "vcell",
@@ -260,7 +269,7 @@ dependencies = [
 [[package]]
 name = "libsupport_zynq"
 version = "0.0.0"
-source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#78d58d17ec7906a6cadd1678576939d20612cf8f"
+source = "git+https://git.m-labs.hk/M-Labs/zynq-rs.git#2c161720fa12f8b7abecaf60f77b062b08ac9bc1"
 dependencies = [
  "cc",
  "compiler_builtins",
@@ -273,17 +282,17 @@ dependencies = [
 
 [[package]]
 name = "linked_list_allocator"
-version = "0.8.8"
+version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e6766dff3bf932e0d1c7f1cf27c0a46008f7839f85b015a312c276a4570a399"
+checksum = "822add9edb1860698b79522510da17bef885171f75aa395cff099d770c609c24"
 
 [[package]]
 name = "log"
-version = "0.4.11"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
 dependencies = [
- "cfg-if",
+ "cfg-if 1.0.0",
 ]
 
 [[package]]
@@ -298,12 +307,6 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c75de51135344a4f8ed3cfe2720dc27736f7711989703a0b43aadf3753c55577"
 
-[[package]]
-name = "memchr"
-version = "2.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
-
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -340,24 +343,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "pin-project"
+name = "pin-project-lite"
-version = "1.0.2"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9ccc2237c2c489783abd8c4c80e5450fc0e98644555b1364da68cc29aa151ca7"
+checksum = "8d31d11c69a6b52a174b42bdc0c30e5e11670f90788b2c471c31c1d17d449443"
-dependencies = [
- "pin-project-internal",
-]
-
-[[package]]
-name = "pin-project-internal"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8e8d2bf0b23038a4424865103a4df472855692821aab4e4f5c3312d461d9e5f"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
 
 [[package]]
 name = "pin-utils"
@@ -373,24 +362,24 @@ checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro-nested"
-version = "0.1.6"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eba180dafb9038b050a4c280019bbedf9f2467b61e5d892dcad585bb57aadc5a"
+checksum = "bc881b2c22681370c6a780e47af9840ef841837bc98118431d4e1868bd0c1086"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.24"
+version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
+checksum = "5c7ed8b8c7b886ea3ed7dde405212185f423ab44682667c8c6dd14aa1d9f6612"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.8"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
+checksum = "c3d0b9745dc2debf507c8422de05d7226cc1f0644216dfdfead988f9b1ab32a7"
 dependencies = [
  "proc-macro2",
 ]
@@ -432,10 +421,25 @@ dependencies = [
 ]
 
 [[package]]
-name = "smoltcp"
+name = "rustc_version"
-version = "0.6.0"
+version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fe46639fd2ec79eadf8fe719f237a7a0bd4dac5d957f1ca5bbdbc1c3c39e53a"
+checksum = "c5f5376ea5e30ce23c03eb77cbe4962b988deead10910c372b226388b594c084"
+dependencies = [
+ "semver",
+]
+
+[[package]]
+name = "semver"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4f410fedcf71af0345d7607d246e7ad15faaadd49d240ee3b24e5dc21a820ac"
+
+[[package]]
+name = "smoltcp"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3e4a069bef843d170df47e7c0a8bf8d037f217d9f5b325865acc3e466ffe40d3"
 dependencies = [
  "bitflags",
  "byteorder",
@@ -444,9 +448,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.55"
+version = "1.0.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a571a711dddd09019ccc628e1b17fe87c59b09d513c06c026877aa708334f37a"
+checksum = "1873d832550d4588c3dbc20f01361ab00bfe741048f71e3fecf145a7cc18b29c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -455,25 +459,25 @@ dependencies = [
 
 [[package]]
 name = "unicode-xid"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7fe0bb3479651439c9112f72b6c505038574c9fbb575ed1bf3b797fa39dd564"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
 [[package]]
 name = "unwind"
 version = "0.0.0"
 dependencies = [
  "cc",
- "cfg-if",
+ "cfg-if 0.1.10",
  "compiler_builtins",
  "libc",
 ]
 
 [[package]]
 name = "vcell"
-version = "0.1.2"
+version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "876e32dcadfe563a4289e994f7cb391197f362b6315dc45e8ba4aa6f564a4b3c"
+checksum = "77439c1b53d2303b20d9459b1ade71a83c716e3f9c34f3228c00e6f185d6c002"
 
 [[package]]
 name = "void"

src/Cargo.toml

@@ -13,6 +13,3 @@ debug = true
 codegen-units = 1
 opt-level = 2
 lto = true
-
-[patch.crates-io]
-core_io = { git = "https://git.m-labs.hk/M-Labs/zynq-rs.git" }

src/libc/build.rs

@@ -5,6 +5,8 @@ fn main() {
 
 mod libc {
     use std::path::Path;
+    use std::env;
+
     pub fn compile() {
         let cfg = &mut cc::Build::new();
         cfg.no_default_flags(true);
@@ -16,6 +18,9 @@ mod libc {
         cfg.flag("-ffreestanding");
         cfg.flag("-fno-PIC");
         cfg.flag("-isystem../include");
+        if let Ok(extra_include) = env::var("CLANG_EXTRA_INCLUDE_DIR") {
+            cfg.flag(&("-isystem".to_owned() + &extra_include));
+        }
         cfg.flag("-fno-stack-protector");
         cfg.flag("--target=armv7-none-eabihf");
         cfg.flag("-O2");

src/libdyld/src/reloc.rs

@@ -123,7 +123,7 @@ pub fn relocate<R: Relocatable>(
             if let Some(addr) = lib.lookup(sym_name) {
                 // First, try to resolve against itself.
                 trace!("looked up symbol {} in image", format_sym_name(sym_name));
-                value = lib.image.ptr() as u32 + addr;
+                value = addr;
             } else if let Some(addr) = resolve(sym_name) {
                 // Second, call the user-provided function.
                 trace!("resolved symbol {:?}", format_sym_name(sym_name));

src/libunwind/build.rs

@@ -6,6 +6,7 @@ fn main() {
 
 mod llvm_libunwind {
     use std::path::Path;
+    use std::env;
 
     fn setup_options(cfg: &mut cc::Build) {
         cfg.no_default_flags(true);
@@ -16,6 +17,9 @@ mod llvm_libunwind {
         cfg.flag("-fno-PIC");
         cfg.flag("-Isrc");
         cfg.flag("-isystem../include");
+        if let Ok(extra_include) = env::var("CLANG_EXTRA_INCLUDE_DIR") {
+            cfg.flag(&("-isystem".to_owned() + &extra_include));
+        }
         cfg.flag("-fno-stack-protector");
         cfg.flag("--target=armv7-none-eabihf");
         cfg.flag("-O2");

src/runtime/src/rpc.rs

@@ -14,15 +14,20 @@ use crate::proto_core_io::ProtoWrite;
 use crate::proto_async;
 use self::tag::{Tag, TagIterator, split_tag};
 
+#[inline]
+fn alignment_offset(alignment: isize, ptr: isize) -> isize {
+    (alignment - ptr % alignment) % alignment
+}
+
 unsafe fn align_ptr<T>(ptr: *const ()) -> *const T {
     let alignment = core::mem::align_of::<T>() as isize;
-    let fix = (alignment - (ptr as isize) % alignment) % alignment;
+    let fix = alignment_offset(alignment, ptr as isize);
     ((ptr as isize) + fix) as *const T
 }
 
 unsafe fn align_ptr_mut<T>(ptr: *mut ()) -> *mut T {
     let alignment = core::mem::align_of::<T>() as isize;
-    let fix = (alignment - (ptr as isize) % alignment) % alignment;
+    let fix = alignment_offset(alignment, ptr as isize);
     ((ptr as isize) + fix) as *mut T
 }
 
@@ -66,6 +71,7 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
             })
         }
         Tag::Tuple(it, arity) => {
+            *data = (*data).offset(alignment_offset(tag.alignment() as isize, *data as isize));
             let mut it = it.clone();
             for _ in 0..arity {
                 let tag = it.next().expect("truncated tag");
@@ -80,17 +86,24 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
                 let length = proto_async::read_i32(stream).await? as usize;
                 (*ptr).length  = length as u32;
                 let tag = it.clone().next().expect("truncated tag");
-                let mut data = alloc(tag.size() * length as usize).await;
+                let data_size = tag.size() * length as usize +
+                    match tag {
+                        Tag::Int64 | Tag::Float64 => 4,
+                        _ => 0
+                    };
+                let mut data = alloc(data_size).await;
 
+                let alignment = tag.alignment();
+                data = data.offset(alignment_offset(alignment as isize, data as isize));
                 (*ptr).elements = data;
                 match tag {
                     Tag::Bool => {
-                        let ptr = align_ptr_mut::<u8>(data);
+                        let ptr = data as *mut u8;
                         let dest = core::slice::from_raw_parts_mut(ptr, length);
                         proto_async::read_chunk(stream, dest).await?;
                     },
                     Tag::Int32 => {
-                        let ptr = align_ptr_mut::<u32>(data);
+                        let ptr = data as *mut u32;
                         // reading as raw bytes and do endianness conversion later
                         let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 4);
                         proto_async::read_chunk(stream, dest).await?;
@@ -99,7 +112,7 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
                         NativeEndian::from_slice_u32(dest);
                     },
                     Tag::Int64 | Tag::Float64 => {
-                        let ptr = align_ptr_mut::<u64>(data);
+                        let ptr = data as *mut u64;
                         let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 8);
                         proto_async::read_chunk(stream, dest).await?;
                         drop(dest);
@@ -125,18 +138,25 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
                 }
 
                 let elt_tag = it.clone().next().expect("truncated tag");
-                *buffer = alloc(elt_tag.size() * total_len as usize).await;
+                let data_size = elt_tag.size() * total_len as usize +
+                    match elt_tag {
+                        Tag::Int64 | Tag::Float64 => 4,
+                        _ => 0
+                    };
+                let mut data = alloc(data_size).await;
 
+                let alignment = tag.alignment();
+                data = data.offset(alignment_offset(alignment as isize, data as isize));
+                *buffer = data;
                 let length = total_len as usize;
-                let mut data = *buffer;
                 match elt_tag {
                     Tag::Bool => {
-                        let ptr = align_ptr_mut::<u8>(data);
+                        let ptr = data as *mut u8;
                         let dest = core::slice::from_raw_parts_mut(ptr, length);
                         proto_async::read_chunk(stream, dest).await?;
                     },
                     Tag::Int32 => {
-                        let ptr = align_ptr_mut::<u32>(data);
+                        let ptr = data as *mut u32;
                         let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 4);
                         proto_async::read_chunk(stream, dest).await?;
                         drop(dest);
@@ -144,7 +164,7 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
                         NativeEndian::from_slice_u32(dest);
                     },
                     Tag::Int64 | Tag::Float64 => {
-                        let ptr = align_ptr_mut::<u64>(data);
+                        let ptr = data as *mut u64;
                         let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 8);
                         proto_async::read_chunk(stream, dest).await?;
                         drop(dest);
@@ -161,6 +181,7 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
             })
         }
         Tag::Range(it) => {
+            *data = (*data).offset(alignment_offset(tag.alignment() as isize, *data as isize));
             let tag = it.clone().next().expect("truncated tag");
             recv_value(stream, tag, data, alloc).await?;
             recv_value(stream, tag, data, alloc).await?;
@@ -407,7 +428,35 @@ mod tag {
             }
         }
 
+        pub fn alignment(self) -> usize {
+            use cslice::CSlice;
+            match self {
+                Tag::None => 1,
+                Tag::Bool => core::mem::align_of::<u8>(),
+                Tag::Int32 => core::mem::align_of::<i32>(),
+                Tag::Int64 => core::mem::align_of::<i64>(),
+                Tag::Float64 => core::mem::align_of::<f64>(),
+                // struct type: align to largest element
+                Tag::Tuple(it, arity) => {
+                    let it = it.clone();
+                    it.take(arity.into()).map(|t| t.alignment()).max().unwrap()
+                },
+                Tag::Range(it) => {
+                    let it = it.clone();
+                    it.take(3).map(|t| t.alignment()).max().unwrap()
+                }
+                // CSlice basically
+                Tag::Bytes | Tag::String | Tag::ByteArray | Tag::List(_) =>
+                    core::mem::align_of::<CSlice<()>>(),
+                // array buffer is allocated, so no need for alignment first
+                Tag::Array(_, _) => 1,
+                // will not be sent from the host
+                _ => unreachable!("unexpected tag from host")
+            }
+        }
+
         pub fn size(self) -> usize {
+            use super::alignment_offset;
             match self {
                 Tag::None => 0,
                 Tag::Bool => 1,
@@ -423,6 +472,8 @@ mod tag {
                     for _ in 0..arity {
                         let tag = it.next().expect("truncated tag");
                         size += tag.size();
+                        // includes padding
+                        size += alignment_offset(tag.alignment() as isize, size as isize) as usize;
                     }
                     size
                 }
@@ -445,10 +496,23 @@ mod tag {
 
     impl<'a> TagIterator<'a> {
         pub fn new(data: &'a [u8]) -> TagIterator<'a> {
-            TagIterator { data: data }
+            TagIterator { data }
         }
 
-        pub fn next(&mut self) -> Option<Tag<'a>> {
+
+        fn sub(&mut self, count: u8) -> TagIterator<'a> {
+            let data = self.data;
+            for _ in 0..count {
+                self.next().expect("truncated tag");
+            }
+            TagIterator { data: &data[..(data.len() - self.data.len())] }
+        }
+    }
+
+    impl<'a> core::iter::Iterator for TagIterator<'a> {
+        type Item = Tag<'a>;
+
+        fn next(&mut self) -> Option<Tag<'a>> {
             if self.data.len() == 0 {
                 return None
             }
@@ -481,14 +545,6 @@ mod tag {
                 _    => unreachable!()
             })
         }
-
-        fn sub(&mut self, count: u8) -> TagIterator<'a> {
-            let data = self.data;
-            for _ in 0..count {
-                self.next().expect("truncated tag");
-            }
-            TagIterator { data: &data[..(data.len() - self.data.len())] }
-        }
     }
 
     impl<'a> fmt::Display for TagIterator<'a> {

zynq-rs.nix

@@ -3,6 +3,6 @@ let
 in
   pkgs.fetchgit {
     url = "https://git.m-labs.hk/M-Labs/zynq-rs.git";
-    rev = "78d58d17ec7906a6cadd1678576939d20612cf8f";
+    rev = "2c161720fa12f8b7abecaf60f77b062b08ac9bc1";
-    sha256 = "1y74i7j9kawhlq22zyicjsxldx9f7h4i22yabw1z4qga19zv6qjd";
+    sha256 = "0zpazkicqzps86r7lgqf09y9ary94mjvxw6gc41z9kjjyxar5fhr";
   }