compiles with toolchain/Cargo.toml updates

Cargo.toml

@@ -19,6 +19,7 @@ members = [
 
     "examples/doom",
     "examples/hello-world",
+    "examples/jam-service-fib",
 ]
 
 [workspace.package]

guest-programs/Cargo.toml

@@ -14,6 +14,7 @@ resolver = "2"
 members = [
     # Examples:
     "example-hello-world",
+    "jam-service-fib",
 
     # Benchmarks:
     "bench-minimal",

guest-programs/jam-service-fib/Cargo.toml

@@ -1,18 +1,17 @@
+cargo-features = ["edition2024"]
+
 [package]
 name = "jam-service-fib"
 version = "0.1.0"
 edition = "2024"
 publish = false
 
-[lib]
-name = "fib"
-path = "src/main.rs"
-crate-type = ["cdylib"]
-
 [[bin]]
 name = "jam-service-fib"
 path = "src/main.rs"
 
 [dependencies]
 polkavm-derive = { path = "../../crates/polkavm-derive" }
 simplealloc = { path = "../../crates/simplealloc" }
+##alloc = "0.5.0" 
+

guest-programs/jam-service-fib/src/main.rs

@@ -1,6 +1,21 @@
 #![no_std]
 #![no_main]
 
+extern crate alloc;
+
+use alloc::vec::Vec;
+use simplealloc::SimpleAlloc;
+
+#[global_allocator]
+static ALLOCATOR: SimpleAlloc<4096> = SimpleAlloc::new();
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    unsafe {
+        core::arch::asm!("unimp", options(noreturn));
+    }
+}
+
 #[polkavm_derive::polkavm_import]
 extern "C" {
     #[polkavm_import(index = 0)]
@@ -73,13 +88,11 @@ fn refine() -> [u8; 12] {
         let fib_n_minus_1 = u32::from_le_bytes(buffer[8..12].try_into().unwrap());
 
         let new_fib_n = fib_n + fib_n_minus_1;
-
-        let new_buffer = [
-            (n + 1).to_le_bytes(),
-            new_fib_n.to_le_bytes(),
-            fib_n.to_le_bytes(),
-        ]
-        .concat();
+        let new_buffer: Vec<u8> = [(n + 1).to_le_bytes(), new_fib_n.to_le_bytes(), fib_n.to_le_bytes()]
+            .iter()
+            .flat_map(|array| array.iter())
+            .copied()
+            .collect();
 
         buffer.copy_from_slice(&new_buffer);
     } else {
@@ -108,7 +121,28 @@ fn on_transfer() -> bool {
     true
 }
 
-// TODO: (1) Get toolchain instructions sufficient to get above Rust compiled into PVM with
-// (a) ecalli 16/17/3 in place of import/export (refine) + write (accumulate)
-// (b) entrypoints 0/5/10/15 going into is_authorized/refine/accumulate/on_transfer
-// (2) get polkatool to output .pvm byte code with (1b) streamlined
+/*
+(1) cargo build works but you have to get toolchain 
+ https://github.com/paritytech/rustc-rv32e-toolchain/ 
+and untar into ~/.rustup/toolchains/
+Then to use it:
+ export RUSTUP_TOOLCHAIN=rve-nightly
+I had to adjust the repo a bit to refer to the above
+
+TODO:
+(1) Get PVM out with ecalli 16/17/3 in place of import/export (refine) + write (accumulate)
+(2) Here is Jan's advice: To emit the JAM entry points and a raw program blob without the .polkavm container then you do need to postprocess the output of the compilation.
+
+    let mut config = polkavm_linker::Config::default();
+    config.set_strip(true);
+    config.set_dispatch_table(vec![
+        b"is_authorized_ext".into(),
+        b"refine_ext".into(),
+        b"accumulate_ext".into(),
+        b"on_transfer_ext".into(),
+    ]);
+    let elf = fs::read("target/riscv32ema-unknown-none-elf/release/jam-service-fib").unwrap();
+    let raw_blob = polkavm_linker::program_from_elf(config, elf.as_ref()).unwrap();
+    let parts = polkavm_linker::ProgramParts::from_bytes(raw_blob.into()).unwrap();
+    std::fs::write("blob.pvm", &parts.code_and_jump_table).unwrap();
+*/

rust-toolchain.toml

@@ -1,2 +1,5 @@
 [toolchain]
-channel = "1.75.0"
+channel = "rve-nightly"
+components = ["rustc", "cargo", "rust-std"]
+targets = ["riscv32imc-unknown-none-elf"]
+