From 14bae099355bda4df6817dbf21031879af57676e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Sun, 28 Mar 2021 20:32:50 +0200
Subject: [PATCH 01/19] load process into itcm

needs newer fixed cortex-m-rt 0.6.13+unreleased
relevant? https://reviews.llvm.org/D81986
---
 .cargo/config       |  1 +
 Cargo.lock          | 20 ++++++++------------
 Cargo.toml          | 25 +++++++++++++++++--------
 build.rs            |  9 +++++++++
 memory.x            | 23 ++++++++++++++++++-----
 src/bin/dual-iir.rs |  2 ++
 src/hardware/mod.rs |  4 ++--
 src/startup.S       | 28 ++++++++++++++++++++++++++++
 8 files changed, 85 insertions(+), 27 deletions(-)
 create mode 100644 build.rs
 create mode 100644 src/startup.S

diff --git a/.cargo/config b/.cargo/config
index deffdfc..ad2c024 100644
--- a/.cargo/config
+++ b/.cargo/config
@@ -1,6 +1,7 @@
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 runner = "gdb-multiarch -q -x openocd.gdb"
 rustflags = [
+    "-C", "link-arg=--nmagic",
     "-C", "link-arg=-Tlink.x",
 # The target (below) defaults to cortex-m4
 # There currently are two different options to go beyond that:
diff --git a/Cargo.lock b/Cargo.lock
index 946a634..03a8558 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -100,6 +100,12 @@ dependencies = [
  "rustc_version",
 ]
 
+[[package]]
+name = "cc"
+version = "1.0.67"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -145,18 +151,13 @@ dependencies = [
 [[package]]
 name = "cortex-m-rt"
 version = "0.6.13"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "980c9d0233a909f355ed297ef122f257942de5e0a2cb1c39f60684b65bcb90fb"
 dependencies = [
  "cortex-m-rt-macros",
- "r0",
 ]
 
 [[package]]
 name = "cortex-m-rt-macros"
-version = "0.1.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4717562afbba06e760d34451919f5c3bf3ac15c7bb897e8b04862a7428378647"
+version = "0.6.11"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -572,12 +573,6 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "r0"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2a38df5b15c8d5c7e8654189744d8e396bddc18ad48041a500ce52d6948941f"
-
 [[package]]
 name = "rand"
 version = "0.8.3"
@@ -720,6 +715,7 @@ version = "0.4.1"
 dependencies = [
  "ad9959",
  "asm-delay",
+ "cc",
  "cortex-m 0.6.7",
  "cortex-m-log",
  "cortex-m-rt",
diff --git a/Cargo.toml b/Cargo.toml
index 8d32d80..a18e595 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -47,6 +47,23 @@ smoltcp-nal = "0.1.0"
 miniconf = "0.1"
 generic-array = "0.14"
 
+[dependencies.mcp23017]
+git = "https://github.com/mrd0ll4r/mcp23017.git"
+
+[dependencies.stm32h7xx-hal]
+features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
+git = "https://github.com/stm32-rs/stm32h7xx-hal"
+branch = "master"
+
+[build-dependencies]
+cc = "1.0"
+
+[patch.crates-io.cortex-m-rt]
+path = "../cortex-m-rt"
+# 0.6.13
+# git = "https://github.com/rust-embedded/cortex-m-rt.git"
+# rev = "8c90451"
+
 [patch.crates-io.miniconf]
 git = "https://github.com/quartiq/miniconf.git"
 branch = "develop"
@@ -67,14 +84,6 @@ branch = "master"
 # a new release of smoltcp is made, we can remove this patch.
 git = "https://github.com/smoltcp-rs/smoltcp.git"
 
-[dependencies.mcp23017]
-git = "https://github.com/mrd0ll4r/mcp23017.git"
-
-[dependencies.stm32h7xx-hal]
-features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
-git = "https://github.com/stm32-rs/stm32h7xx-hal"
-branch = "master"
-
 [features]
 semihosting = ["panic-semihosting", "cortex-m-log/semihosting"]
 bkpt = [ ]
diff --git a/build.rs b/build.rs
new file mode 100644
index 0000000..3f9eaf9
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,9 @@
+fn main() {
+    println!("cargo:rerun-if-changed=memory.x");
+
+    cc::Build::new()
+        .file("src/startup.S")
+        .compile("startup");
+    println!("cargo:rerun-if-changed=src/startup.S");
+}
+
diff --git a/memory.x b/memory.x
index c1569ce..a132517 100644
--- a/memory.x
+++ b/memory.x
@@ -13,10 +13,6 @@ MEMORY
 }
 
 SECTIONS {
-  .itcm : ALIGN(8) {
-    *(.itcm .itcm.*);
-    . = ALIGN(8);
-    } > ITCM
   .axisram (NOLOAD) : ALIGN(8) {
     *(.axisram .axisram.*);
     . = ALIGN(8);
@@ -33,4 +29,21 @@ SECTIONS {
     *(.sram3 .sram3.*);
     . = ALIGN(4);
     } > SRAM3
-} INSERT AFTER .bss;
+  .itcm : ALIGN(8) {
+    . = ALIGN(8);
+    __sitcm = .;
+    *(.itcm .itcm.*);
+    . = ALIGN(8);
+    __eitcm = .;
+  } > ITCM AT>FLASH
+  __siitcm = LOADADDR(.itcm);
+
+/* This may be the only insert location that doesn't affect those __[es]...
+ * that are (unfortunately) placed outside their sections */
+} INSERT BEFORE .uninit;
+
+ASSERT(__sitcm % 8 == 0 && __eitcm % 8 == 0, "
+BUG(cortex-m-rt): .itcm is not 8-byte aligned");
+
+ASSERT(__siitcm % 4 == 0, "
+BUG(cortex-m-rt): the LMA of .itcm is not 4-byte aligned");
diff --git a/src/bin/dual-iir.rs b/src/bin/dual-iir.rs
index 4a27d48..5a878dc 100644
--- a/src/bin/dual-iir.rs
+++ b/src/bin/dual-iir.rs
@@ -110,6 +110,8 @@ const APP: () = {
     /// Because the ADC and DAC operate at the same rate, these two constraints actually implement
     /// the same time bounds, meeting one also means the other is also met.
     #[task(binds=DMA1_STR4, resources=[adcs, dacs, iir_state, iir_ch], priority=2)]
+    #[inline(never)]
+    #[link_section = ".itcm.process"]
     fn process(c: process::Context) {
         let adc_samples = [
             c.resources.adcs.0.acquire_buffer(),
diff --git a/src/hardware/mod.rs b/src/hardware/mod.rs
index cc7a34a..a83c9d6 100644
--- a/src/hardware/mod.rs
+++ b/src/hardware/mod.rs
@@ -58,11 +58,11 @@ fn panic(_info: &core::panic::PanicInfo) -> ! {
 }
 
 #[cortex_m_rt::exception]
-fn HardFault(ef: &cortex_m_rt::ExceptionFrame) -> ! {
+unsafe fn HardFault(ef: &cortex_m_rt::ExceptionFrame) -> ! {
     panic!("HardFault at {:#?}", ef);
 }
 
 #[cortex_m_rt::exception]
-fn DefaultHandler(irqn: i16) {
+unsafe fn DefaultHandler(irqn: i16) {
     panic!("Unhandled exception (IRQn = {})", irqn);
 }
diff --git a/src/startup.S b/src/startup.S
new file mode 100644
index 0000000..b85bf11
--- /dev/null
+++ b/src/startup.S
@@ -0,0 +1,28 @@
+.cfi_sections .debug_frame
+
+# .thumb
+.section .text.pre_init, "ax"
+.globl __pre_init
+.type __pre_init,%function
+.thumb_func
+.cfi_startproc
+__pre_init:
+  # Analogous to cortex-m-rt Reset code for .data copying.
+  # Initialise .itcm code. `__sitcm`, `__siitcm`, and `__eitcm` come from the
+  # linker script. Copy from r2 into r0 until r0 reaches r1.
+  ldr r0,=__sitcm
+  ldr r1,=__eitcm
+  ldr r2,=__siitcm
+1:
+  cmp r1, r0
+  beq 2f
+  # load 1 word from r2 to r3, inc r2
+  ldm r2!, {r3}
+  # store 1 word from r3 to r0, inc r0
+  stm r0!, {r3}
+  b 1b
+2:
+  dsb
+  isb
+  bx lr
+.cfi_endproc

From fc7374424a75876c67cafac877fbbc03aba39bc9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Mon, 29 Mar 2021 18:51:50 +0200
Subject: [PATCH 02/19] enable itcm/dtcm explicitly

---
 src/startup.S | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/startup.S b/src/startup.S
index b85bf11..3a5b6ea 100644
--- a/src/startup.S
+++ b/src/startup.S
@@ -7,6 +7,22 @@
 .thumb_func
 .cfi_startproc
 __pre_init:
+
+  # Enable ITCM and DTCM
+  ldr r0, =1
+  ldr r1, =0xE000EF90
+  ldr r2, [r1]
+  # Set ITCMCR.EN
+  orr r2, r2, r0
+  str r2, [r1]
+  ldr r1, =0xE000EF94
+  ldr r2, [r1]
+  # Set DTCMCR.EN
+  orr r2, r2, r0
+  str r2, [r1]
+  dsb
+  isb
+
   # Analogous to cortex-m-rt Reset code for .data copying.
   # Initialise .itcm code. `__sitcm`, `__siitcm`, and `__eitcm` come from the
   # linker script. Copy from r2 into r0 until r0 reaches r1.

From cd3cfa63e6248c66e34ea1fe0af1fcb72a74c58f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Tue, 20 Apr 2021 13:26:07 +0200
Subject: [PATCH 03/19] memory.x: remove comment about old cortex-m-rt

---
 memory.x | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/memory.x b/memory.x
index a132517..d87640a 100644
--- a/memory.x
+++ b/memory.x
@@ -37,10 +37,7 @@ SECTIONS {
     __eitcm = .;
   } > ITCM AT>FLASH
   __siitcm = LOADADDR(.itcm);
-
-/* This may be the only insert location that doesn't affect those __[es]...
- * that are (unfortunately) placed outside their sections */
-} INSERT BEFORE .uninit;
+} INSERT AFTER .uninit;
 
 ASSERT(__sitcm % 8 == 0 && __eitcm % 8 == 0, "
 BUG(cortex-m-rt): .itcm is not 8-byte aligned");

From 9e66054d211870441f9a8429d443c5796bfe1674 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 29 Apr 2021 16:39:01 +0200
Subject: [PATCH 04/19] bump cortex-m-rt to 0.6.13+git

---
 Cargo.lock | 2 ++
 Cargo.toml | 6 ++----
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 03a8558..d8e7782 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -151,6 +151,7 @@ dependencies = [
 [[package]]
 name = "cortex-m-rt"
 version = "0.6.13"
+source = "git+https://github.com/rust-embedded/cortex-m-rt.git?rev=a2e3ad5#a2e3ad54478c6b98e519a1b0946395d790c0b6c7"
 dependencies = [
  "cortex-m-rt-macros",
 ]
@@ -158,6 +159,7 @@ dependencies = [
 [[package]]
 name = "cortex-m-rt-macros"
 version = "0.6.11"
+source = "git+https://github.com/rust-embedded/cortex-m-rt.git?rev=a2e3ad5#a2e3ad54478c6b98e519a1b0946395d790c0b6c7"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index a18e595..e6559a0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -59,10 +59,8 @@ branch = "master"
 cc = "1.0"
 
 [patch.crates-io.cortex-m-rt]
-path = "../cortex-m-rt"
-# 0.6.13
-# git = "https://github.com/rust-embedded/cortex-m-rt.git"
-# rev = "8c90451"
+git = "https://github.com/rust-embedded/cortex-m-rt.git"
+rev = "a2e3ad5"
 
 [patch.crates-io.miniconf]
 git = "https://github.com/quartiq/miniconf.git"

From 23bdd816a7c70cda274f83d47f4ff3dacae63611 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 29 Apr 2021 16:44:12 +0200
Subject: [PATCH 05/19] dependencies: align with master

---
 Cargo.toml | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index e6559a0..3499ac3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -47,14 +47,6 @@ smoltcp-nal = "0.1.0"
 miniconf = "0.1"
 generic-array = "0.14"
 
-[dependencies.mcp23017]
-git = "https://github.com/mrd0ll4r/mcp23017.git"
-
-[dependencies.stm32h7xx-hal]
-features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
-git = "https://github.com/stm32-rs/stm32h7xx-hal"
-branch = "master"
-
 [build-dependencies]
 cc = "1.0"
 
@@ -82,6 +74,14 @@ branch = "master"
 # a new release of smoltcp is made, we can remove this patch.
 git = "https://github.com/smoltcp-rs/smoltcp.git"
 
+[dependencies.mcp23017]
+git = "https://github.com/mrd0ll4r/mcp23017.git"
+
+[dependencies.stm32h7xx-hal]
+features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
+git = "https://github.com/stm32-rs/stm32h7xx-hal"
+branch = "master"
+
 [features]
 semihosting = ["panic-semihosting", "cortex-m-log/semihosting"]
 bkpt = [ ]

From 780b3441a21dbdbc3782a52d400cb7d1d84344f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 29 Apr 2021 17:33:20 +0200
Subject: [PATCH 06/19] fmt

---
 build.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/build.rs b/build.rs
index 3f9eaf9..d0c281d 100644
--- a/build.rs
+++ b/build.rs
@@ -1,9 +1,6 @@
 fn main() {
     println!("cargo:rerun-if-changed=memory.x");
 
-    cc::Build::new()
-        .file("src/startup.S")
-        .compile("startup");
+    cc::Build::new().file("src/startup.S").compile("startup");
     println!("cargo:rerun-if-changed=src/startup.S");
 }
-

From b8b3bc0873267a055a2a3709043d8b28baf44ca9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 29 Apr 2021 17:44:54 +0200
Subject: [PATCH 07/19] gha: install gcc

---
 .github/workflows/ci.yml      | 2 ++
 .github/workflows/release.yml | 1 +
 2 files changed, 3 insertions(+)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index cf68b3f..be5ebcc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,6 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
@@ -51,6 +52,7 @@ jobs:
             features: nightly
     steps:
       - uses: actions/checkout@v2
+      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.toolchain }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 5be1311..50e0dd8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -12,6 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable

From ff5f3af8a49b0472be0c3e60a2d5925f237d2f83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Thu, 13 May 2021 15:22:44 +0200
Subject: [PATCH 08/19] remove duplicate linker option

---
 .cargo/config | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.cargo/config b/.cargo/config
index 0682cd0..82780fa 100644
--- a/.cargo/config
+++ b/.cargo/config
@@ -2,7 +2,6 @@
 runner = "probe-run --chip STM32H743ZITx --speed 30000"
 # runner = "gdb-multiarch -q -x openocd.gdb"
 rustflags = [
-    "-C", "link-arg=--nmagic",
     "-C", "link-arg=-Tlink.x",
     "-C", "link-arg=--nmagic",
     "-C", "target-cpu=cortex-m7",

From 4d5f1ab5e916494adeaff8f917548d8335b4191b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 14 May 2021 17:20:08 +0200
Subject: [PATCH 09/19] itcm: implement in rust and execute during setup()

---
 .github/workflows/ci.yml      |  2 --
 .github/workflows/release.yml |  1 -
 Cargo.lock                    |  7 ------
 Cargo.toml                    |  3 ---
 build.rs                      |  3 ---
 src/hardware/configuration.rs | 30 ++++++++++++++++++++++++
 src/startup.S                 | 44 -----------------------------------
 7 files changed, 30 insertions(+), 60 deletions(-)
 delete mode 100644 src/startup.S

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index be5ebcc..cf68b3f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
@@ -52,7 +51,6 @@ jobs:
             features: nightly
     steps:
       - uses: actions/checkout@v2
-      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.toolchain }}
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 0463aa6..475c05e 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -12,7 +12,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - run: sudo apt install gcc-arm-none-eabi
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: stable
diff --git a/Cargo.lock b/Cargo.lock
index a10d3c1..a85ba18 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -102,12 +102,6 @@ dependencies = [
  "rustc_version",
 ]
 
-[[package]]
-name = "cc"
-version = "1.0.67"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3c69b077ad434294d3ce9f1f6143a2a4b89a8a2d54ef813d85003a4fd1137fd"
-
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -756,7 +750,6 @@ version = "0.5.0"
 dependencies = [
  "ad9959",
  "asm-delay",
- "cc",
  "cortex-m 0.7.2",
  "cortex-m-rt",
  "cortex-m-rtic",
diff --git a/Cargo.toml b/Cargo.toml
index 9fcec81..63c1846 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -58,9 +58,6 @@ rev = "61933f857a"
 features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
 version = "0.9.0"
 
-[build-dependencies]
-cc = "1.0"
-
 [patch.crates-io.cortex-m-rt]
 git = "https://github.com/rust-embedded/cortex-m-rt.git"
 rev = "a2e3ad5"
diff --git a/build.rs b/build.rs
index d0c281d..e71f6a6 100644
--- a/build.rs
+++ b/build.rs
@@ -1,6 +1,3 @@
 fn main() {
     println!("cargo:rerun-if-changed=memory.x");
-
-    cc::Build::new().file("src/startup.S").compile("startup");
-    println!("cargo:rerun-if-changed=src/startup.S");
 }
diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index f48b3d2..f762d48 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -105,6 +105,32 @@ pub struct PounderDevices {
 /// Static storage for the ethernet DMA descriptor ring.
 static mut DES_RING: ethernet::DesRing = ethernet::DesRing::new();
 
+/// Setup ITCM and load its code from flash
+unsafe fn setup_itcm() {
+    extern "C" {
+        static mut __sitcm: u32;
+        static mut __eitcm: u32;
+        static mut __siitcm: u32;
+    }
+    use core::{ptr, slice, sync::atomic};
+
+    // ITCM is enabled on reset on our CPU but might not be on others.
+    // Keep for completeness.
+    const ITCMCR: *mut u32 = 0xE000_EF90usize as _;
+    ptr::write_volatile(ITCMCR, ptr::read_volatile(ITCMCR) | 1);
+    atomic::fence(atomic::Ordering::SeqCst);
+
+    let len =
+        (&__eitcm as *const u32).offset_from(&__sitcm as *const _) as usize;
+    let dst = slice::from_raw_parts_mut(&mut __sitcm as *mut _, len);
+    let src = slice::from_raw_parts(&__siitcm as *const _, len);
+    dst.copy_from_slice(src);
+
+    atomic::fence(atomic::Ordering::SeqCst);
+    cortex_m::asm::dsb();
+    cortex_m::asm::isb();
+}
+
 /// Configure the stabilizer hardware for operation.
 ///
 /// # Args
@@ -160,6 +186,10 @@ pub fn setup(
         log::info!("starting...");
     }
 
+    unsafe {
+        setup_itcm();
+    }
+
     // Set up the system timer for RTIC scheduling.
     {
         let tim15 =
diff --git a/src/startup.S b/src/startup.S
deleted file mode 100644
index 3a5b6ea..0000000
--- a/src/startup.S
+++ /dev/null
@@ -1,44 +0,0 @@
-.cfi_sections .debug_frame
-
-# .thumb
-.section .text.pre_init, "ax"
-.globl __pre_init
-.type __pre_init,%function
-.thumb_func
-.cfi_startproc
-__pre_init:
-
-  # Enable ITCM and DTCM
-  ldr r0, =1
-  ldr r1, =0xE000EF90
-  ldr r2, [r1]
-  # Set ITCMCR.EN
-  orr r2, r2, r0
-  str r2, [r1]
-  ldr r1, =0xE000EF94
-  ldr r2, [r1]
-  # Set DTCMCR.EN
-  orr r2, r2, r0
-  str r2, [r1]
-  dsb
-  isb
-
-  # Analogous to cortex-m-rt Reset code for .data copying.
-  # Initialise .itcm code. `__sitcm`, `__siitcm`, and `__eitcm` come from the
-  # linker script. Copy from r2 into r0 until r0 reaches r1.
-  ldr r0,=__sitcm
-  ldr r1,=__eitcm
-  ldr r2,=__siitcm
-1:
-  cmp r1, r0
-  beq 2f
-  # load 1 word from r2 to r3, inc r2
-  ldm r2!, {r3}
-  # store 1 word from r3 to r0, inc r0
-  stm r0!, {r3}
-  b 1b
-2:
-  dsb
-  isb
-  bx lr
-.cfi_endproc

From 75a38dfba963a4d447b2a3af8cb7e86c3d7d7796 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 14 May 2021 17:36:47 +0200
Subject: [PATCH 10/19] deps: add rationales for git dependencies

---
 Cargo.toml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 63c1846..00acb22 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -46,10 +46,12 @@ miniconf = "0.1.0"
 shared-bus = {version = "0.2.2", features = ["cortex-m"] }
 serde-json-core = "0.3"
 
+# rtt-target bump
 [dependencies.rtt-logger]
 git = "https://github.com/quartiq/rtt-logger.git"
 rev = "70b0eb5"
 
+# rewrite
 [dependencies.mcp23017]
 git = "https://github.com/mrd0ll4r/mcp23017.git"
 rev = "61933f857a"
@@ -58,6 +60,7 @@ rev = "61933f857a"
 features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
 version = "0.9.0"
 
+# link.x section start/end
 [patch.crates-io.cortex-m-rt]
 git = "https://github.com/rust-embedded/cortex-m-rt.git"
 rev = "a2e3ad5"

From 23a93e913511c2d158f9a2c66f64933322ca9f1e Mon Sep 17 00:00:00 2001
From: Ryan Summers <ryan.summers@vertigo-designs.com>
Date: Wed, 26 May 2021 13:05:54 +0200
Subject: [PATCH 11/19] Removing spurious settings updates

---
 src/bin/dual-iir.rs |  9 ++++++---
 src/bin/lockin.rs   |  9 ++++++---
 src/net/mod.rs      | 15 ++++++++++++---
 3 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/src/bin/dual-iir.rs b/src/bin/dual-iir.rs
index 29eb474..012cdde 100644
--- a/src/bin/dual-iir.rs
+++ b/src/bin/dual-iir.rs
@@ -13,7 +13,7 @@ use hardware::{
     DigitalInput0, DigitalInput1, InputPin, SystemTimer, AFE0, AFE1,
 };
 
-use net::{NetworkUsers, Telemetry, TelemetryBuffer, UpdateState};
+use net::{NetworkState, NetworkUsers, Telemetry, TelemetryBuffer};
 
 const SCALE: f32 = i16::MAX as _;
 
@@ -171,8 +171,11 @@ const APP: () = {
     fn idle(mut c: idle::Context) -> ! {
         loop {
             match c.resources.network.lock(|net| net.update()) {
-                UpdateState::Updated => c.spawn.settings_update().unwrap(),
-                UpdateState::NoChange => cortex_m::asm::wfi(),
+                NetworkState::SettingsChanged => {
+                    c.spawn.settings_update().unwrap()
+                }
+                NetworkState::Updated => {}
+                NetworkState::NoChange => cortex_m::asm::wfi(),
             }
         }
     }
diff --git a/src/bin/lockin.rs b/src/bin/lockin.rs
index a187767..7200eb4 100644
--- a/src/bin/lockin.rs
+++ b/src/bin/lockin.rs
@@ -17,7 +17,7 @@ use stabilizer::hardware::{
 };
 
 use miniconf::Miniconf;
-use net::{NetworkUsers, Telemetry, TelemetryBuffer, UpdateState};
+use net::{NetworkState, NetworkUsers, Telemetry, TelemetryBuffer};
 
 // A constant sinusoid to send on the DAC output.
 // Full-scale gives a +/- 10.24V amplitude waveform. Scale it down to give +/- 1V.
@@ -248,8 +248,11 @@ const APP: () = {
     fn idle(mut c: idle::Context) -> ! {
         loop {
             match c.resources.network.lock(|net| net.update()) {
-                UpdateState::Updated => c.spawn.settings_update().unwrap(),
-                UpdateState::NoChange => cortex_m::asm::wfi(),
+                NetworkState::SettingsChanged => {
+                    c.spawn.settings_update().unwrap()
+                }
+                NetworkState::Updated => {}
+                NetworkState::NoChange => cortex_m::asm::wfi(),
             }
         }
     }
diff --git a/src/net/mod.rs b/src/net/mod.rs
index 38499ca..64c9401 100644
--- a/src/net/mod.rs
+++ b/src/net/mod.rs
@@ -33,6 +33,12 @@ pub enum UpdateState {
     Updated,
 }
 
+#[derive(Copy, Clone, PartialEq)]
+pub enum NetworkState {
+    SettingsChanged,
+    Updated,
+    NoChange,
+}
 /// A structure of Stabilizer's default network users.
 pub struct NetworkUsers<S: Default + Clone + Miniconf, T: Serialize> {
     pub miniconf: MiniconfClient<S>,
@@ -98,15 +104,18 @@ where
     ///
     /// # Returns
     /// An indication if any of the network users indicated a state change.
-    pub fn update(&mut self) -> UpdateState {
+    pub fn update(&mut self) -> NetworkState {
         // Poll for incoming data.
-        let poll_result = self.processor.update();
+        let poll_result = match self.processor.update() {
+            UpdateState::NoChange => NetworkState::NoChange,
+            UpdateState::Updated => NetworkState::Updated,
+        };
 
         // Update the MQTT clients.
         self.telemetry.update();
 
         match self.miniconf.update() {
-            UpdateState::Updated => UpdateState::Updated,
+            UpdateState::Updated => NetworkState::SettingsChanged,
             UpdateState::NoChange => poll_result,
         }
     }

From f10bce709fcf486cdd7da7fe34127e99521f7ba3 Mon Sep 17 00:00:00 2001
From: Ryan Summers <ryan.summers@vertigo-designs.com>
Date: Thu, 27 May 2021 13:42:52 +0200
Subject: [PATCH 12/19] Updating the embedded-nal

---
 Cargo.lock                 | 62 ++++++++++++++++++++++++--------------
 Cargo.toml                 |  4 +--
 src/net/miniconf_client.rs |  9 +++---
 src/net/shared.rs          | 14 ++++-----
 src/net/telemetry.rs       |  6 ++--
 5 files changed, 55 insertions(+), 40 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 274b2bb..5402ed9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -42,6 +42,15 @@ dependencies = [
  "embedded-hal",
 ]
 
+[[package]]
+name = "atomic-polyfill"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "30302dda7a66f8c55932ebf208f7def840743ff64d495e9ceffcd97c18f11d39"
+dependencies = [
+ "cortex-m 0.7.2",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.0.1"
@@ -240,11 +249,11 @@ dependencies = [
 
 [[package]]
 name = "embedded-nal"
-version = "0.1.0"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae46eb1b02de5a76d9d0ea21d657ff5b0ad2cc47f3a7723608227b1dd1b3eb18"
+checksum = "db9efecb57ab54fa918730f2874d7d37647169c50fa1357fecb81abee840b113"
 dependencies = [
- "heapless 0.5.6",
+ "heapless 0.7.1",
  "nb 1.0.0",
  "no-std-net",
 ]
@@ -317,24 +326,21 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "hash32"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0c35f58762feb77d74ebe43bdbc3210f09be9fe6742234d573bacc26ed92b67"
+dependencies = [
+ "byteorder",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
 
-[[package]]
-name = "heapless"
-version = "0.5.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74911a68a1658cfcfb61bc0ccfbd536e3b6e906f8c2f7883ee50157e3e2184f1"
-dependencies = [
- "as-slice",
- "generic-array 0.13.3",
- "hash32",
- "stable_deref_trait",
-]
-
 [[package]]
 name = "heapless"
 version = "0.6.1"
@@ -343,11 +349,22 @@ checksum = "634bd4d29cbf24424d0a4bfcbf80c6960129dc24424752a7d1d1390607023422"
 dependencies = [
  "as-slice",
  "generic-array 0.14.4",
- "hash32",
+ "hash32 0.1.1",
  "serde",
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "heapless"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7ee8a997d259962217f40279f34201fdf06e669bafa69d7c1f4c7ff1893b5f6"
+dependencies = [
+ "atomic-polyfill",
+ "hash32 0.2.1",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.6.2"
@@ -409,13 +426,12 @@ dependencies = [
 [[package]]
 name = "minimq"
 version = "0.2.0"
-source = "git+https://github.com/quartiq/minimq.git?rev=d2ec3e8#d2ec3e8351fa403ea96defd98c0b4410cbaa18a4"
+source = "git+https://github.com/quartiq/minimq.git?branch=feature/nal-update#98c1dffc4b0eeeaadf696320e1ce4234d5b52de0"
 dependencies = [
  "bit_field",
  "embedded-nal",
  "enum-iterator",
- "generic-array 0.14.4",
- "heapless 0.6.1",
+ "heapless 0.7.1",
 ]
 
 [[package]]
@@ -454,9 +470,9 @@ dependencies = [
 
 [[package]]
 name = "no-std-net"
-version = "0.4.0"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2178127478ae4ee9be7180bc9c3bffb6354dd7238400db567102f98c413a9f35"
+checksum = "1bcece43b12349917e096cddfa66107277f123e6c96a5aea78711dc601a47152"
 
 [[package]]
 name = "num"
@@ -745,10 +761,10 @@ dependencies = [
 [[package]]
 name = "smoltcp-nal"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=4a1711c#4a1711c54cdf79f5ee8c1c99a1e8984f5944270c"
+source = "git+https://github.com/quartiq/smoltcp-nal.git?branch=feature/nal-update#65d94c4ab9e06d2e5c48547a0c9cd6836591e355"
 dependencies = [
  "embedded-nal",
- "heapless 0.6.1",
+ "heapless 0.7.1",
  "nanorand",
  "smoltcp",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 790363a..29de739 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -64,11 +64,11 @@ rev = "c6f2b28"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
-rev = "4a1711c"
+branch = "feature/nal-update"
 
 [dependencies.minimq]
 git = "https://github.com/quartiq/minimq.git"
-rev = "d2ec3e8"
+branch = "feature/nal-update"
 
 [features]
 nightly = ["cortex-m/inline-asm", "dsp/nightly"]
diff --git a/src/net/miniconf_client.rs b/src/net/miniconf_client.rs
index b809d73..76c64d2 100644
--- a/src/net/miniconf_client.rs
+++ b/src/net/miniconf_client.rs
@@ -21,7 +21,7 @@ where
     S: miniconf::Miniconf + Default + Clone,
 {
     default_response_topic: String<consts::U128>,
-    mqtt: minimq::MqttClient<minimq::consts::U256, NetworkReference>,
+    mqtt: minimq::Minimq<NetworkReference, 256>,
     settings: S,
     subscribed: bool,
     settings_prefix: String<consts::U64>,
@@ -39,8 +39,7 @@ where
     /// * `prefix` - The MQTT device prefix to use for this device.
     pub fn new(stack: NetworkReference, client_id: &str, prefix: &str) -> Self {
         let mqtt =
-            minimq::MqttClient::new(MQTT_BROKER.into(), client_id, stack)
-                .unwrap();
+            minimq::Minimq::new(MQTT_BROKER.into(), client_id, stack).unwrap();
 
         let mut response_topic: String<consts::U128> = String::from(prefix);
         response_topic.push_str("/log").unwrap();
@@ -62,7 +61,7 @@ where
     /// # Returns
     /// An option containing an action that should be completed as a result of network servicing.
     pub fn update(&mut self) -> UpdateState {
-        let mqtt_connected = match self.mqtt.is_connected() {
+        let mqtt_connected = match self.mqtt.client.is_connected() {
             Ok(connected) => connected,
             Err(minimq::Error::Network(
                 smoltcp_nal::NetworkError::NoIpAddress,
@@ -88,7 +87,7 @@ where
 
             // We do not currently handle or process potential subscription failures. Instead, this
             // failure will be logged through the stabilizer logging interface.
-            self.mqtt.subscribe(&settings_topic, &[]).unwrap();
+            self.mqtt.client.subscribe(&settings_topic, &[]).unwrap();
             self.subscribed = true;
         }
 
diff --git a/src/net/shared.rs b/src/net/shared.rs
index e09489b..4f86793 100644
--- a/src/net/shared.rs
+++ b/src/net/shared.rs
@@ -47,25 +47,25 @@ impl<'a, S> NetworkStackProxy<'a, S> {
 // proxy structure.
 macro_rules! forward {
     ($func:ident($($v:ident: $IT:ty),*) -> $T:ty) => {
-        fn $func(&self, $($v: $IT),*) -> $T {
+        fn $func(&mut self, $($v: $IT),*) -> $T {
             self.mutex.lock(|stack| stack.$func($($v),*))
         }
     }
 }
 
 // Implement a TCP stack for the proxy if the underlying network stack implements it.
-impl<'a, S> embedded_nal::TcpStack for NetworkStackProxy<'a, S>
+impl<'a, S> embedded_nal::TcpClientStack for NetworkStackProxy<'a, S>
 where
-    S: embedded_nal::TcpStack,
+    S: embedded_nal::TcpClientStack,
 {
     type TcpSocket = S::TcpSocket;
     type Error = S::Error;
 
-    forward! {open(mode: embedded_nal::Mode) -> Result<S::TcpSocket, S::Error>}
-    forward! {connect(socket: S::TcpSocket, remote: embedded_nal::SocketAddr) -> Result<S::TcpSocket, S::Error>}
+    forward! {socket() -> Result<S::TcpSocket, S::Error>}
+    forward! {connect(socket: &mut S::TcpSocket, remote: embedded_nal::SocketAddr) -> embedded_nal::nb::Result<(), S::Error>}
     forward! {is_connected(socket: &S::TcpSocket) -> Result<bool, S::Error>}
-    forward! {write(socket: &mut S::TcpSocket, buffer: &[u8]) -> embedded_nal::nb::Result<usize, S::Error>}
-    forward! {read(socket: &mut S::TcpSocket, buffer: &mut [u8]) -> embedded_nal::nb::Result<usize, S::Error>}
+    forward! {send(socket: &mut S::TcpSocket, buffer: &[u8]) -> embedded_nal::nb::Result<usize, S::Error>}
+    forward! {receive(socket: &mut S::TcpSocket, buffer: &mut [u8]) -> embedded_nal::nb::Result<usize, S::Error>}
     forward! {close(socket: S::TcpSocket) -> Result<(), S::Error>}
 }
 
diff --git a/src/net/telemetry.rs b/src/net/telemetry.rs
index b59b222..b6b9c34 100644
--- a/src/net/telemetry.rs
+++ b/src/net/telemetry.rs
@@ -21,7 +21,7 @@ use crate::hardware::{
 
 /// The telemetry client for reporting telemetry data over MQTT.
 pub struct TelemetryClient<T: Serialize> {
-    mqtt: minimq::MqttClient<minimq::consts::U256, NetworkReference>,
+    mqtt: minimq::Minimq<NetworkReference, 256>,
     telemetry_topic: String<consts::U128>,
     _telemetry: core::marker::PhantomData<T>,
 }
@@ -97,8 +97,7 @@ impl<T: Serialize> TelemetryClient<T> {
     /// A new telemetry client.
     pub fn new(stack: NetworkReference, client_id: &str, prefix: &str) -> Self {
         let mqtt =
-            minimq::MqttClient::new(MQTT_BROKER.into(), client_id, stack)
-                .unwrap();
+            minimq::Minimq::new(MQTT_BROKER.into(), client_id, stack).unwrap();
 
         let mut telemetry_topic: String<consts::U128> = String::from(prefix);
         telemetry_topic.push_str("/telemetry").unwrap();
@@ -122,6 +121,7 @@ impl<T: Serialize> TelemetryClient<T> {
         let telemetry: Vec<u8, consts::U256> =
             serde_json_core::to_vec(telemetry).unwrap();
         self.mqtt
+            .client
             .publish(&self.telemetry_topic, &telemetry, QoS::AtMostOnce, &[])
             .ok();
     }

From fc2801ecbb4ee6243a2a0173a11ff2157731778a Mon Sep 17 00:00:00 2001
From: Ryan Summers <ryan.summers@vertigo-designs.com>
Date: Thu, 27 May 2021 17:15:31 +0200
Subject: [PATCH 13/19] Updating dependencies

---
 Cargo.lock | 8 ++++----
 Cargo.toml | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5402ed9..0bba018 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -38,7 +38,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9a69a963b70ddacfcd382524f72a4576f359af9334b3bf48a79566590bb8bfa"
 dependencies = [
  "bitrate",
- "cortex-m 0.7.2",
+ "cortex-m 0.6.7",
  "embedded-hal",
 ]
 
@@ -426,7 +426,7 @@ dependencies = [
 [[package]]
 name = "minimq"
 version = "0.2.0"
-source = "git+https://github.com/quartiq/minimq.git?branch=feature/nal-update#98c1dffc4b0eeeaadf696320e1ce4234d5b52de0"
+source = "git+https://github.com/quartiq/minimq.git?rev=dbdbec0#dbdbec0b77d2e134dc6c025018a82c14cbdfbe34"
 dependencies = [
  "bit_field",
  "embedded-nal",
@@ -761,7 +761,7 @@ dependencies = [
 [[package]]
 name = "smoltcp-nal"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/smoltcp-nal.git?branch=feature/nal-update#65d94c4ab9e06d2e5c48547a0c9cd6836591e355"
+source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=5e56576#5e56576fbbc594f0a0e1df9222a20eb35c8e7511"
 dependencies = [
  "embedded-nal",
  "heapless 0.7.1",
@@ -810,7 +810,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b672c837e0ee8158ecc7fce0f9a948dd0693a9c588338e728d14b73307a0b7d"
 dependencies = [
  "bare-metal 0.2.5",
- "cortex-m 0.7.2",
+ "cortex-m 0.6.7",
  "cortex-m-rt",
  "vcell",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 29de739..14be160 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -64,11 +64,11 @@ rev = "c6f2b28"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
-branch = "feature/nal-update"
+rev = "5e56576"
 
 [dependencies.minimq]
 git = "https://github.com/quartiq/minimq.git"
-branch = "feature/nal-update"
+rev = "dbdbec0"
 
 [features]
 nightly = ["cortex-m/inline-asm", "dsp/nightly"]

From 14c68474690be9ebdb5eeffa3a8a330f1b32c245 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Thu, 27 May 2021 15:53:15 +0000
Subject: [PATCH 14/19] build(deps): bump ndarray from 0.15.1 to 0.15.2

Bumps [ndarray](https://github.com/rust-ndarray/ndarray) from 0.15.1 to 0.15.2.
- [Release notes](https://github.com/rust-ndarray/ndarray/releases)
- [Changelog](https://github.com/rust-ndarray/ndarray/blob/master/RELEASES.md)
- [Commits](https://github.com/rust-ndarray/ndarray/compare/0.15.1...0.15.2)

Signed-off-by: dependabot[bot] <support@github.com>
---
 Cargo.lock | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 0bba018..2235321 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -38,7 +38,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9a69a963b70ddacfcd382524f72a4576f359af9334b3bf48a79566590bb8bfa"
 dependencies = [
  "bitrate",
- "cortex-m 0.6.7",
+ "cortex-m 0.7.2",
  "embedded-hal",
 ]
 
@@ -457,9 +457,9 @@ checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
 
 [[package]]
 name = "ndarray"
-version = "0.15.1"
+version = "0.15.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc1372704f14bb132a49a6701c2238970a359ee0829fed481b522a63bf25456a"
+checksum = "02b2e4807aaa21dc6dcc3417e5902dc199c3648043bf27b7af4b202332fe4760"
 dependencies = [
  "matrixmultiply",
  "num-complex",
@@ -810,7 +810,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b672c837e0ee8158ecc7fce0f9a948dd0693a9c588338e728d14b73307a0b7d"
 dependencies = [
  "bare-metal 0.2.5",
- "cortex-m 0.6.7",
+ "cortex-m 0.7.2",
  "cortex-m-rt",
  "vcell",
 ]

From c5d3837745e94f71dd01aed644f30edb27bd0aa7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 28 May 2021 16:03:40 +0200
Subject: [PATCH 15/19] itcm: add some comments, make it safe

---
 src/hardware/configuration.rs | 53 ++++++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 16 deletions(-)

diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index f762d48..23121df 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -105,8 +105,17 @@ pub struct PounderDevices {
 /// Static storage for the ethernet DMA descriptor ring.
 static mut DES_RING: ethernet::DesRing = ethernet::DesRing::new();
 
-/// Setup ITCM and load its code from flash
-unsafe fn setup_itcm() {
+/// Setup ITCM and load its code from flash.
+///
+/// For portability and maintainability this is implemented in Rust.
+/// Since this is implemented in Rust the compiler may assume that bss and data are set
+/// up already. There is no easy way to ensure this implementation will never need bss
+/// or data. Hence we can't safely run this as the cortex-m-rt `pre_init` hook before
+/// bss/data is setup.
+///
+/// Calling (through IRQ or directly) any code in ITCM before having called
+/// this method is undefined.
+fn load_itcm() {
     extern "C" {
         static mut __sitcm: u32;
         static mut __eitcm: u32;
@@ -114,18 +123,29 @@ unsafe fn setup_itcm() {
     }
     use core::{ptr, slice, sync::atomic};
 
-    // ITCM is enabled on reset on our CPU but might not be on others.
-    // Keep for completeness.
-    const ITCMCR: *mut u32 = 0xE000_EF90usize as _;
-    ptr::write_volatile(ITCMCR, ptr::read_volatile(ITCMCR) | 1);
-    atomic::fence(atomic::Ordering::SeqCst);
+    // NOTE(unsafe): Assuming the address symbols from the linker as well as
+    // the source instruction data are all valid, this is safe as it only
+    // copies linker-prepared data to where the code expects it to be.
+    // Calling it multiple times is safe as well.
 
-    let len =
-        (&__eitcm as *const u32).offset_from(&__sitcm as *const _) as usize;
-    let dst = slice::from_raw_parts_mut(&mut __sitcm as *mut _, len);
-    let src = slice::from_raw_parts(&__siitcm as *const _, len);
-    dst.copy_from_slice(src);
+    unsafe {
+        // ITCM is enabled on reset on our CPU but might not be on others.
+        // Keep for completeness.
+        const ITCMCR: *mut u32 = 0xE000_EF90usize as _;
+        ptr::write_volatile(ITCMCR, ptr::read_volatile(ITCMCR) | 1);
 
+        // Ensure ITCM is enabled before loading.
+        atomic::fence(atomic::Ordering::SeqCst);
+
+        let len =
+            (&__eitcm as *const u32).offset_from(&__sitcm as *const _) as usize;
+        let dst = slice::from_raw_parts_mut(&mut __sitcm as *mut _, len);
+        let src = slice::from_raw_parts(&__siitcm as *const _, len);
+        // Load code into ITCM.
+        dst.copy_from_slice(src);
+    }
+
+    // Ensure ITCM is loaded before potentially executing any instructions from it.
     atomic::fence(atomic::Ordering::SeqCst);
     cortex_m::asm::dsb();
     cortex_m::asm::isb();
@@ -183,12 +203,12 @@ pub fn setup(
         log::set_logger(&LOGGER)
             .map(|()| log::set_max_level(log::LevelFilter::Trace))
             .unwrap();
-        log::info!("starting...");
+        log::info!("Starting");
     }
 
-    unsafe {
-        setup_itcm();
-    }
+    // Before being able to call any code in ITCM, load that code from flash.
+    log::info!("Loading ITCM");
+    load_itcm();
 
     // Set up the system timer for RTIC scheduling.
     {
@@ -902,6 +922,7 @@ pub fn setup(
 
         #[cfg(feature = "pounder_v1_1")]
         let pounder_stamper = {
+            logger::info!("Pounder v1.1 or later");
             let etr_pin = gpioa.pa0.into_alternate_af3();
 
             // The frequency in the constructor is dont-care, as we will modify the period + clock

From 79d30b4c6b454b0b5676331207b72a8a3e0e4072 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 28 May 2021 16:32:26 +0200
Subject: [PATCH 16/19] setup: cleanup

---
 src/hardware/configuration.rs | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index 23121df..e2eb653 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -207,7 +207,6 @@ pub fn setup(
     }
 
     // Before being able to call any code in ITCM, load that code from flash.
-    log::info!("Loading ITCM");
     load_itcm();
 
     // Set up the system timer for RTIC scheduling.
@@ -922,7 +921,7 @@ pub fn setup(
 
         #[cfg(feature = "pounder_v1_1")]
         let pounder_stamper = {
-            logger::info!("Pounder v1.1 or later");
+            log::info!("Assuming Pounder v1.1 or later");
             let etr_pin = gpioa.pa0.into_alternate_af3();
 
             // The frequency in the constructor is dont-care, as we will modify the period + clock
@@ -985,13 +984,13 @@ pub fn setup(
         digital_inputs,
     };
 
+    // Enable the instruction cache.
+    core.SCB.enable_icache();
+
     // info!("Version {} {}", build_info::PKG_VERSION, build_info::GIT_VERSION.unwrap());
     // info!("Built on {}", build_info::BUILT_TIME_UTC);
     // info!("{} {}", build_info::RUSTC_VERSION, build_info::TARGET);
     log::info!("setup() complete");
 
-    // Enable the instruction cache.
-    core.SCB.enable_icache();
-
     (stabilizer, pounder)
 }

From e9e98678c1130048bbfed05e2776e83a2e13fbe2 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Fri, 28 May 2021 14:40:46 +0000
Subject: [PATCH 17/19] build(deps): bump heapless from 0.6.1 to 0.7.1

Bumps [heapless](https://github.com/japaric/heapless) from 0.6.1 to 0.7.1.
- [Release notes](https://github.com/japaric/heapless/releases)
- [Changelog](https://github.com/japaric/heapless/blob/master/CHANGELOG.md)
- [Commits](https://github.com/japaric/heapless/compare/v0.6.1...v0.7.1)

Signed-off-by: dependabot[bot] <support@github.com>
---
 Cargo.lock | 4 ++--
 Cargo.toml | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5791b3a..1c7edfe 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -347,7 +347,6 @@ dependencies = [
  "as-slice",
  "generic-array 0.14.4",
  "hash32 0.1.1",
- "serde",
  "stable_deref_trait",
 ]
 
@@ -359,6 +358,7 @@ checksum = "c7ee8a997d259962217f40279f34201fdf06e669bafa69d7c1f4c7ff1893b5f6"
 dependencies = [
  "atomic-polyfill",
  "hash32 0.2.1",
+ "serde",
  "stable_deref_trait",
 ]
 
@@ -771,7 +771,7 @@ dependencies = [
  "cortex-m-rtic",
  "dsp",
  "embedded-hal",
- "heapless 0.6.1",
+ "heapless 0.7.1",
  "log",
  "mcp23017",
  "miniconf",
diff --git a/Cargo.toml b/Cargo.toml
index 2eb2430..6dedf83 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,7 +33,7 @@ cortex-m-rt = { version = "0.6", features = ["device"] }
 log = { version = "0.4", features = ["max_level_trace", "release_max_level_info"] }
 rtt-target = { version = "0.3", features = ["cortex-m"] }
 serde = { version = "1.0", features = ["derive"], default-features = false }
-heapless = { version = "0.6", features = ["serde"] }
+heapless = { version = "0.7", features = ["serde"] }
 cortex-m-rtic = "0.5.6"
 embedded-hal = "0.2.5"
 nb = "1.0.0"

From 440e542eaeaf1ffd52fcc535c029fcc197161836 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Fri, 28 May 2021 14:40:51 +0000
Subject: [PATCH 18/19] Bump serde-json-core from 0.3.0 to 0.4.0

Bumps [serde-json-core](https://github.com/rust-embedded-community/serde-json-core) from 0.3.0 to 0.4.0.
- [Release notes](https://github.com/rust-embedded-community/serde-json-core/releases)
- [Changelog](https://github.com/rust-embedded-community/serde-json-core/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-embedded-community/serde-json-core/compare/v0.3.0...v0.4.0)

Signed-off-by: dependabot[bot] <support@github.com>
---
 Cargo.lock | 15 +++++++++++++--
 Cargo.toml |  2 +-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5791b3a..baa6afd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -417,7 +417,7 @@ source = "git+https://github.com/quartiq/miniconf.git?rev=c6f2b28#c6f2b28f735e27
 dependencies = [
  "derive_miniconf",
  "serde",
- "serde-json-core",
+ "serde-json-core 0.3.0",
 ]
 
 [[package]]
@@ -717,6 +717,17 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "serde-json-core"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8014aeea272bca0f0779778d43253f2f3375b414185b30e6ecc4d3e4a9994781"
+dependencies = [
+ "heapless 0.7.1",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serde_derive"
 version = "1.0.126"
@@ -782,7 +793,7 @@ dependencies = [
  "rtt-logger",
  "rtt-target",
  "serde",
- "serde-json-core",
+ "serde-json-core 0.4.0",
  "shared-bus",
  "smoltcp-nal",
  "stm32h7xx-hal",
diff --git a/Cargo.toml b/Cargo.toml
index 2eb2430..a8b3132 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,7 +44,7 @@ dsp = { path = "dsp" }
 ad9959 = { path = "ad9959" }
 miniconf = "0.1.0"
 shared-bus = {version = "0.2.2", features = ["cortex-m"] }
-serde-json-core = "0.3"
+serde-json-core = "0.4"
 
 # rtt-target bump
 [dependencies.rtt-logger]

From b8da9961b82d4a82bd2558ca8492b19d363faf83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20J=C3=B6rdens?= <rj@quartiq.de>
Date: Fri, 28 May 2021 18:34:25 +0200
Subject: [PATCH 19/19] adapt to new heapless/serde-json-core after
 const-generics

---
 Cargo.lock                    | 19 ++++---------------
 Cargo.toml                    |  2 +-
 src/hardware/configuration.rs |  4 ++--
 src/net/messages.rs           | 11 +++++------
 src/net/miniconf_client.rs    | 12 ++++++------
 src/net/mod.rs                |  8 ++++----
 src/net/telemetry.rs          |  8 ++++----
 7 files changed, 26 insertions(+), 38 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1c415e8..d60b5a2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -200,7 +200,7 @@ dependencies = [
 [[package]]
 name = "derive_miniconf"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/miniconf.git?rev=c6f2b28#c6f2b28f735e27b337eaa986846536e904c6f2bd"
+source = "git+https://github.com/quartiq/miniconf.git?rev=2750533#275053396f0334e9efefa1ab2aae4c19b95a9a53"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -413,11 +413,11 @@ dependencies = [
 [[package]]
 name = "miniconf"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/miniconf.git?rev=c6f2b28#c6f2b28f735e27b337eaa986846536e904c6f2bd"
+source = "git+https://github.com/quartiq/miniconf.git?rev=2750533#275053396f0334e9efefa1ab2aae4c19b95a9a53"
 dependencies = [
  "derive_miniconf",
  "serde",
- "serde-json-core 0.3.0",
+ "serde-json-core",
 ]
 
 [[package]]
@@ -706,17 +706,6 @@ dependencies = [
  "serde_derive",
 ]
 
-[[package]]
-name = "serde-json-core"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39af17f40c2a28d2c9a7918663ddc8a10f54cc6f109ead5c3f010869761df186"
-dependencies = [
- "heapless 0.6.1",
- "ryu",
- "serde",
-]
-
 [[package]]
 name = "serde-json-core"
 version = "0.4.0"
@@ -793,7 +782,7 @@ dependencies = [
  "rtt-logger",
  "rtt-target",
  "serde",
- "serde-json-core 0.4.0",
+ "serde-json-core",
  "shared-bus",
  "smoltcp-nal",
  "stm32h7xx-hal",
diff --git a/Cargo.toml b/Cargo.toml
index 66dc0a8..21dbd54 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -67,7 +67,7 @@ rev = "a2e3ad5"
 
 [patch.crates-io.miniconf]
 git = "https://github.com/quartiq/miniconf.git"
-rev = "c6f2b28"
+rev = "2750533"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index e2eb653..02aed76 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -9,7 +9,7 @@ use stm32h7xx_hal::{
 
 const NUM_SOCKETS: usize = 4;
 
-use heapless::{consts, Vec};
+use heapless::Vec;
 use smoltcp_nal::smoltcp;
 
 use embedded_hal::digital::v2::{InputPin, OutputPin};
@@ -642,7 +642,7 @@ pub fn setup(
             let mut sockets =
                 smoltcp::socket::SocketSet::new(&mut store.sockets[..]);
 
-            let mut handles: Vec<smoltcp::socket::SocketHandle, consts::U64> =
+            let mut handles: Vec<smoltcp::socket::SocketHandle, 64> =
                 Vec::new();
             for storage in store.socket_storage.iter_mut() {
                 let tcp_socket = {
diff --git a/src/net/messages.rs b/src/net/messages.rs
index 167e440..3887fef 100644
--- a/src/net/messages.rs
+++ b/src/net/messages.rs
@@ -1,4 +1,4 @@
-use heapless::{consts, String, Vec};
+use heapless::{String, Vec};
 use serde::Serialize;
 
 use core::fmt::Write;
@@ -12,15 +12,15 @@ pub enum SettingsResponseCode {
 /// Represents a generic MQTT message.
 pub struct MqttMessage<'a> {
     pub topic: &'a str,
-    pub message: Vec<u8, consts::U128>,
-    pub properties: Vec<minimq::Property<'a>, consts::U1>,
+    pub message: Vec<u8, 128>,
+    pub properties: Vec<minimq::Property<'a>, 1>,
 }
 
 /// The payload of the MQTT response message to a settings update request.
 #[derive(Serialize)]
 pub struct SettingsResponse {
     code: u8,
-    msg: String<heapless::consts::U64>,
+    msg: String<64>,
 }
 
 impl<'a> MqttMessage<'a> {
@@ -48,8 +48,7 @@ impl<'a> MqttMessage<'a> {
             .unwrap_or(&default_response);
 
         // Associate any provided correlation data with the response.
-        let mut correlation_data: Vec<minimq::Property<'a>, consts::U1> =
-            Vec::new();
+        let mut correlation_data: Vec<minimq::Property<'a>, 1> = Vec::new();
         if let Some(data) = properties
             .iter()
             .find(|prop| matches!(prop, minimq::Property::CorrelationData(_)))
diff --git a/src/net/miniconf_client.rs b/src/net/miniconf_client.rs
index 76c64d2..cc838f6 100644
--- a/src/net/miniconf_client.rs
+++ b/src/net/miniconf_client.rs
@@ -10,7 +10,7 @@
 ///!
 ///! Respones to settings updates are sent without quality-of-service guarantees, so there's no
 ///! guarantee that the requestee will be informed that settings have been applied.
-use heapless::{consts, String};
+use heapless::String;
 
 use super::{MqttMessage, NetworkReference, SettingsResponse, UpdateState};
 use crate::hardware::design_parameters::MQTT_BROKER;
@@ -20,11 +20,11 @@ pub struct MiniconfClient<S>
 where
     S: miniconf::Miniconf + Default + Clone,
 {
-    default_response_topic: String<consts::U128>,
+    default_response_topic: String<128>,
     mqtt: minimq::Minimq<NetworkReference, 256>,
     settings: S,
     subscribed: bool,
-    settings_prefix: String<consts::U64>,
+    settings_prefix: String<64>,
 }
 
 impl<S> MiniconfClient<S>
@@ -41,10 +41,10 @@ where
         let mqtt =
             minimq::Minimq::new(MQTT_BROKER.into(), client_id, stack).unwrap();
 
-        let mut response_topic: String<consts::U128> = String::from(prefix);
+        let mut response_topic: String<128> = String::from(prefix);
         response_topic.push_str("/log").unwrap();
 
-        let mut settings_prefix: String<consts::U64> = String::from(prefix);
+        let mut settings_prefix: String<64> = String::from(prefix);
         settings_prefix.push_str("/settings").unwrap();
 
         Self {
@@ -81,7 +81,7 @@ where
         if !self.subscribed && mqtt_connected {
             // Note(unwrap): We construct a string with two more characters than the prefix
             // strucutre, so we are guaranteed to have space for storage.
-            let mut settings_topic: String<consts::U66> =
+            let mut settings_topic: String<66> =
                 String::from(self.settings_prefix.as_str());
             settings_topic.push_str("/#").unwrap();
 
diff --git a/src/net/mod.rs b/src/net/mod.rs
index 64c9401..bdb871f 100644
--- a/src/net/mod.rs
+++ b/src/net/mod.rs
@@ -5,7 +5,7 @@
 ///! telemetry (via MQTT), configuration of run-time settings (via MQTT + Miniconf), and live data
 ///! streaming over raw UDP/TCP sockets. This module encompasses the main processing routines
 ///! related to Stabilizer networking operations.
-use heapless::{consts, String};
+use heapless::String;
 use miniconf::Miniconf;
 use serde::Serialize;
 
@@ -134,7 +134,7 @@ fn get_client_id(
     app: &str,
     client: &str,
     mac: smoltcp_nal::smoltcp::wire::EthernetAddress,
-) -> String<consts::U64> {
+) -> String<64> {
     let mut identifier = String::new();
     write!(&mut identifier, "{}-{}-{}", app, mac, client).unwrap();
     identifier
@@ -151,10 +151,10 @@ fn get_client_id(
 pub fn get_device_prefix(
     app: &str,
     mac: smoltcp_nal::smoltcp::wire::EthernetAddress,
-) -> String<consts::U128> {
+) -> String<128> {
     // Note(unwrap): The mac address + binary name must be short enough to fit into this string. If
     // they are defined too long, this will panic and the device will fail to boot.
-    let mut prefix: String<consts::U128> = String::new();
+    let mut prefix: String<128> = String::new();
     write!(&mut prefix, "dt/sinara/{}/{}", app, mac).unwrap();
 
     prefix
diff --git a/src/net/telemetry.rs b/src/net/telemetry.rs
index b6b9c34..d976fee 100644
--- a/src/net/telemetry.rs
+++ b/src/net/telemetry.rs
@@ -10,7 +10,7 @@
 ///! sampling frequency. Instead, the raw codes are stored and the telemetry is generated as
 ///! required immediately before transmission. This ensures that any slower computation required
 ///! for unit conversion can be off-loaded to lower priority tasks.
-use heapless::{consts, String, Vec};
+use heapless::{String, Vec};
 use minimq::QoS;
 use serde::Serialize;
 
@@ -22,7 +22,7 @@ use crate::hardware::{
 /// The telemetry client for reporting telemetry data over MQTT.
 pub struct TelemetryClient<T: Serialize> {
     mqtt: minimq::Minimq<NetworkReference, 256>,
-    telemetry_topic: String<consts::U128>,
+    telemetry_topic: String<128>,
     _telemetry: core::marker::PhantomData<T>,
 }
 
@@ -99,7 +99,7 @@ impl<T: Serialize> TelemetryClient<T> {
         let mqtt =
             minimq::Minimq::new(MQTT_BROKER.into(), client_id, stack).unwrap();
 
-        let mut telemetry_topic: String<consts::U128> = String::from(prefix);
+        let mut telemetry_topic: String<128> = String::from(prefix);
         telemetry_topic.push_str("/telemetry").unwrap();
 
         Self {
@@ -118,7 +118,7 @@ impl<T: Serialize> TelemetryClient<T> {
     /// # Args
     /// * `telemetry` - The telemetry to report
     pub fn publish(&mut self, telemetry: &T) {
-        let telemetry: Vec<u8, consts::U256> =
+        let telemetry: Vec<u8, 256> =
             serde_json_core::to_vec(telemetry).unwrap();
         self.mqtt
             .client