feat(avm): add AvmContextInputs

noir-projects/aztec-nr/aztec/src/context/avm_context.nr

@@ -3,15 +3,17 @@ use dep::protocol_types::traits::Serialize;
 use dep::protocol_types::abis::function_selector::FunctionSelector;
 use dep::protocol_types::abis::public_circuit_public_inputs::PublicCircuitPublicInputs;
 use dep::protocol_types::constants::RETURN_VALUES_LENGTH;
-use crate::context::inputs::PublicContextInputs;
+use crate::context::inputs::avm_context_inputs::AvmContextInputs;
 use crate::context::interface::ContextInterface;
 use crate::context::interface::PublicContextInterface;
 
-struct AVMContext {}
+struct AVMContext {
+    inputs: AvmContextInputs,
+}
 
 impl AVMContext {
-    pub fn new() -> Self {
-        AVMContext {}
+    pub fn new(inputs: AvmContextInputs) -> Self {
+        AVMContext { inputs }
     }
 
     pub fn origin(self) -> AztecAddress {
@@ -190,16 +192,14 @@ impl ContextInterface for AVMContext {
         version()
     }
     fn selector(self) -> FunctionSelector {
-        assert(false, "'selector' not implemented!");
-        FunctionSelector::zero()
+        FunctionSelector::from_field(self.inputs.selector)
     }
     fn get_header(self) -> Header {
         assert(false, "'get_header' not implemented!");
         Header::empty()
     }
     fn get_args_hash(self) -> Field {
-        assert(false, "'get_args_hash' not implemented!");
-        0
+        self.inputs.args_hash
     }
 }
 

noir-projects/aztec-nr/aztec/src/context/inputs.nr

@@ -1,5 +1,7 @@
 mod private_context_inputs;
 mod public_context_inputs;
+mod avm_context_inputs;
 
 use crate::context::inputs::private_context_inputs::PrivateContextInputs;
 use crate::context::inputs::public_context_inputs::PublicContextInputs;
+use crate::context::inputs::avm_context_inputs::AvmContextInputs;

noir-projects/aztec-nr/aztec/src/context/inputs/avm_context_inputs.nr

@@ -0,0 +1,4 @@
+struct AvmContextInputs {
+    selector: Field,
+    args_hash: Field,
+}

noir-projects/noir-contracts/contracts/avm_test_contract/src/main.nr

@@ -232,6 +232,16 @@ contract AvmTest {
     //     context.contract_call_depth()
     // }
 
+    #[aztec(public-vm)]
+    fn check_selector() {
+        assert(context.selector() == FunctionSelector::from_signature("check_selector()"));
+    }
+
+    #[aztec(public-vm)]
+    fn get_args_hash(_a: u8, _fields: [Field; 3]) -> pub Field {
+        context.get_args_hash()
+    }
+
     #[aztec(public-vm)]
     fn emit_unencrypted_log() {
         context.accumulate_unencrypted_logs(/*event_selector=*/ 5, /*message=*/ [10, 20, 30]);

noir/noir-repo/aztec_macros/src/transforms/functions.rs

@@ -116,6 +116,10 @@ pub fn transform_vm_function(
     let create_context = create_avm_context()?;
     func.def.body.0.insert(0, create_context);
 
+    // Add the inputs to the params (first!)
+    let input = create_inputs("AvmContextInputs");
+    func.def.parameters.insert(0, input);
+
     // We want the function to be seen as a public function
     func.def.is_unconstrained = true;
 
@@ -353,11 +357,14 @@ fn create_context(ty: &str, params: &[Param]) -> Result<Vec<Statement>, AztecMac
 ///     // ...
 /// }
 fn create_avm_context() -> Result<Statement, AztecMacroError> {
+    // Create the inputs to the context
+    let inputs_expression = variable("inputs");
+
     let let_context = mutable_assignment(
         "context", // Assigned to
         call(
             variable_path(chained_dep!("aztec", "context", "AVMContext", "new")), // Path
-            vec![],                                                               // args
+            vec![inputs_expression],                                              // args
         ),
     );
 

yarn-project/simulator/src/avm/avm_context.test.ts

@@ -1,6 +1,6 @@
 import { AztecAddress, Fr } from '@aztec/circuits.js';
 
-import { allSameExcept, initContext } from './fixtures/index.js';
+import { allSameExcept, anyAvmContextInputs, initContext } from './fixtures/index.js';
 
 describe('Avm Context', () => {
   it('New call should fork context correctly', () => {
@@ -15,7 +15,8 @@ describe('Avm Context', () => {
       allSameExcept(context.environment, {
         address: newAddress,
         storageAddress: newAddress,
-        calldata: newCalldata,
+        // Calldata also includes AvmContextInputs
+        calldata: anyAvmContextInputs().concat(newCalldata),
         isStaticCall: false,
       }),
     );
@@ -41,7 +42,8 @@ describe('Avm Context', () => {
       allSameExcept(context.environment, {
         address: newAddress,
         storageAddress: newAddress,
-        calldata: newCalldata,
+        // Calldata also includes AvmContextInputs
+        calldata: anyAvmContextInputs().concat(newCalldata),
         isStaticCall: true,
       }),
     );

yarn-project/simulator/src/avm/avm_execution_environment.test.ts

@@ -1,6 +1,6 @@
 import { Fr } from '@aztec/foundation/fields';
 
-import { allSameExcept, initExecutionEnvironment } from './fixtures/index.js';
+import { allSameExcept, anyAvmContextInputs, initExecutionEnvironment } from './fixtures/index.js';
 
 describe('Execution Environment', () => {
   const newAddress = new Fr(123456n);
@@ -14,7 +14,8 @@ describe('Execution Environment', () => {
       allSameExcept(executionEnvironment, {
         address: newAddress,
         storageAddress: newAddress,
-        calldata,
+        // Calldata also includes AvmContextInputs
+        calldata: anyAvmContextInputs().concat(calldata),
       }),
     );
   });
@@ -27,7 +28,8 @@ describe('Execution Environment', () => {
       allSameExcept(executionEnvironment, {
         address: newAddress,
         isDelegateCall: true,
-        calldata,
+        // Calldata also includes AvmContextInputs
+        calldata: anyAvmContextInputs().concat(calldata),
       }),
     );
   });
@@ -41,7 +43,8 @@ describe('Execution Environment', () => {
         address: newAddress,
         storageAddress: newAddress,
         isStaticCall: true,
-        calldata,
+        // Calldata also includes AvmContextInputs
+        calldata: anyAvmContextInputs().concat(calldata),
       }),
     );
   });

yarn-project/simulator/src/avm/avm_execution_environment.ts

@@ -1,8 +1,19 @@
 import { FunctionSelector, GlobalVariables } from '@aztec/circuits.js';
 import { AztecAddress } from '@aztec/foundation/aztec-address';
+import { pedersenHash } from '@aztec/foundation/crypto';
 import { EthAddress } from '@aztec/foundation/eth-address';
 import { Fr } from '@aztec/foundation/fields';
 
+export class AvmContextInputs {
+  static readonly SIZE = 2;
+
+  constructor(private selector: Fr, private argsHash: Fr) {}
+
+  public toFields(): Fr[] {
+    return [this.selector, this.argsHash];
+  }
+}
+
 /**
  * Contains variables that remain constant during AVM execution
  * These variables are provided by the public kernel circuit
@@ -40,7 +51,15 @@ export class AvmExecutionEnvironment {
     // containing all functions, and function selector will become an application-level mechanism
     // (e.g. first few bytes of calldata + compiler-generated jump table)
     public readonly temporaryFunctionSelector: FunctionSelector,
-  ) {}
+  ) {
+    // We encode some extra inputs (AvmContextInputs) in calldata.
+    // This will have to go once we move away from one proof per call.
+    const inputs = new AvmContextInputs(
+      temporaryFunctionSelector.toField(),
+      pedersenHash(calldata.map(word => word.toBuffer())),
+    );
+    this.calldata = [...inputs.toFields(), ...calldata];
+  }
 
   public deriveEnvironmentForNestedCall(
     address: AztecAddress,