building secp256k1-sys for RISCV

riscv.md

@@ -26,3 +26,60 @@ brew tap riscv-software-src/riscv
 
 brew install riscv-tools
 ```
+
+### path
+
+CC=/usr/local/Cellar/riscv-gnu-toolchain/main/bin/riscv64-unknown-elf-gcc cargo build --target=riscv32imc-esp-espidf
+
+CC=/Users/evanfeenstra/code/sphinx-key/sphinx-key/signer/.embuild/espressif/tools/riscv32-esp-elf/esp-2021r2-patch3-8.4.0/riscv32-esp-elf/bin/riscv32-esp-elf-gcc-8.4.0 cargo build --target=riscv32imc-esp-espidf
+
+### point to local dep
+
+```sh
+git clone https://github.com/devrandom/rust-secp256k1.git secp256k1
+
+cd secp256k1
+
+checkout 4e745ebe7e4c9cd0a7e9c8d5c42e989522e52f71
+
+cd secp256k1-sys
+```
+
+rust-toolchain.toml:
+```yaml
+[toolchain]
+channel = "nightly"
+```
+
+.cargo/config.toml
+```yaml
+[build]
+target = "riscv32imc-esp-espidf"
+
+[target.riscv32imc-esp-espidf]
+linker = "ldproxy"
+
+rustflags = ["-C", "default-linker-libraries"]
+
+[unstable]
+
+build-std = ["std", "panic_abort"]
+
+[env]
+ESP_IDF_VERSION = { value = "branch:release/v4.4" }
+```
+
+in build.rs:
+```rs
+// Actual build
+let mut base_config = cc::Build::new();
+// add this with your path to embuild gcc:
+base_config.compiler(std::path::PathBuf::from(
+   "/Users/evanfeenstra/code/sphinx-key/sphinx-key/signer/.embuild/espressif/tools/riscv32-esp-elf/esp-2021r2-patch3-8.4.0/riscv32-esp-elf/bin/riscv32-esp-elf-gcc"
+));
+```
+
+and use path dep in Cargo.toml
+```yaml
+secp256k1-sys = { path = "../../secp256k1/secp256k1-sys" }
+```

signer/.cargo/config.toml

@@ -1,15 +1,6 @@
 [build]
 target = "riscv32imc-esp-espidf"
 
-[target.xtensa-esp32-espidf]
-linker = "ldproxy"
-
-[target.xtensa-esp32s2-espidf]
-linker = "ldproxy"
-
-[target.xtensa-esp32s3-espidf]
-linker = "ldproxy"
-
 [target.riscv32imc-esp-espidf]
 linker = "ldproxy"
 
@@ -17,6 +8,11 @@ linker = "ldproxy"
 # See also https://github.com/ivmarkov/embuild/issues/16
 rustflags = ["-C", "default-linker-libraries"]
 
+# [target.riscv32imc-esp-espidf.rustsecp256k1_v0_5_0]
+# linker = "/Users/evanfeenstra/code/sphinx-key/sphinx-key/signer/.embuild/espressif/tools/riscv32-esp-elf/esp-2021r2-patch3-8.4.0/riscv32-esp-elf/bin/riscv32-esp-elf-gcc"
+# rustc-link-search = ["/Users/evanfeenstra/code/sphinx-key/rust-secp256k1/target/riscv32imc-esp-espidf/debug/libsecp256k1_sys.rlib"]
+# rustc-link-lib = ["rustsecp256k1_v0_5_0"]
+
 [unstable]
 
 build-std = ["std", "panic_abort"]

signer/Cargo.toml

@@ -17,7 +17,8 @@ pio = ["esp-idf-sys/pio"]
 
 [dependencies]
 esp-idf-sys = { version = "0.31.5", features = ["binstart"] }
-vls-protocol-signer = { path = "../../validating-lightning-signer/vls-protocol-signer", default-features = false, features = ["secp-lowmemory"] }
+# vls-protocol-signer = { path = "../../validating-lightning-signer/vls-protocol-signer", features = ["secp-lowmemory"] }
+secp256k1-sys = { path = "../../rust-secp256k1/secp256k1-sys" }
 
 [build-dependencies]
 embuild = "0.29"

signer/src/main.rs

@@ -1,9 +1,12 @@
 use esp_idf_sys as _; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported
+// use vls_protocol_signer;
 
 fn main() {
     // Temporary. Will disappear once ESP-IDF 4.4 is released, but for now it is necessary to call this function once,
     // or else some patches to the runtime implemented by esp-idf-sys might not link properly.
     esp_idf_sys::link_patches();
 
+    let mut parity: secp256k1_sys::types::c_int = 0;
+
     println!("Hello, world!");
 }