Configuration Schema Reference
This reference documents the CPU configuration file schema used by RiescueD. Configuration files are JSON format and define the target system’s memory map, features, and test generation parameters.
Required Configuration Elements
reset_pc
The program counter value when the processor starts.
Type: String (hexadecimal) or Integer
Examples:
"reset_pc": "0x8000_0000"
"reset_pc": "0x80000000"
"reset_pc": 2147483648
mmap - Memory Map
Defines the system memory layout with DRAM and I/O regions.
Type: Object
Structure:
{
"mmap": {
"dram": { },
"io": { }
}
}
Memory Map Components
dram - DRAM Configuration
Main system memory regions where code and data are allocated.
Type: Object with named regions
Region Properties:
address(required) - Starting memory address (string or integer)size(required) - Size of the memory region (string or integer)
Examples:
"dram": {
"region0": {
"address": "0x8000_0000",
"size": "0x10_0000_0000_0000"
},
"main_ram": {
"address": "0x80000000",
"size": "0x40000000"
}
}
io - I/O Configuration
Memory-mapped I/O regions and devices.
Type: Object
Properties:
address(required) - I/O region base addresssize(required) - Total I/O region sizeitems(optional) - Named I/O devices within the region
I/O Item Properties:
address(required) - Device base addresssize(required) - Device sizetest_access(optional) - Determines if location can be used as a random memory address:trueorfalse. Defaults tofalse
Examples:
"io": {
"io0": {
"address": "0x0",
"size": "0x1_0000"
},
"uart": {
"address": "0x200_c000",
"size": "0x5ff_4000",
"test_access": "available"
},
"htif": {
"address": "0x7000_0000",
"size": "0x10"
}
}
Special I/O Devices:
htif- Host-Target Interface, specifies the default end-of-test address (tohost)
Feature Configuration
features - Extension Configuration
Configures RISC-V extensions and their availability.
Type: Object with extension names as keys
Extension Properties:
supported(required) - Whether extension is supported by target (boolean)enabled(required) - Whether extension is enabled by default (boolean)randomize(required) - Percentage chance of randomization (0-100)
Standard Extensions:
rv64/rv32- Architecture widthi- Base integer instruction setm- Integer multiplication and divisiona- Atomic instructionsf- Single-precision floating-pointd- Double-precision floating-pointc- Compressed instructionsh- Hypervisor extensionv- Vector extensionu- User modes- Supervisor mode
Examples:
"features": {
"rv64": {"supported": true, "enabled": true, "randomize": 100},
"i": {"supported": true, "enabled": true, "randomize": 100},
"m": {"supported": true, "enabled": true, "randomize": 100},
"a": {"supported": true, "enabled": true, "randomize": 100},
"f": {"supported": true, "enabled": true, "randomize": 100},
"d": {"supported": true, "enabled": true, "randomize": 100},
"c": {"supported": true, "enabled": true, "randomize": 100},
"h": {"supported": true, "enabled": true, "randomize": 100},
"v": {"supported": true, "enabled": false, "randomize": 100},
"u": {"supported": true, "enabled": true, "randomize": 100},
"s": {"supported": true, "enabled": true, "randomize": 100}
}
Test Generation Parameters
test_generation - Generation Settings
Controls various aspects of test generation behavior.
Type: Object
Properties:
secure_access_probability- Percentage chance of secure access patterns (0-100)secure_pt_probability- Percentage chance of secure page table generation (0-100)a_d_bit_randomization- Percentage chance of randomizing accessed/dirty bits (0-100)pbmt_ncio_randomization- Percentage chance of PBMT NCIO randomization (0-100)
Examples:
"test_generation": {
"secure_access_probability": 30,
"secure_pt_probability": 0,
"a_d_bit_randomization": 0,
"pbmt_ncio_randomization": 0
}
Complete Configuration Example
Here’s a complete configuration file example:
{
"reset_pc": "0x8000_0000",
"mmap": {
"dram": {
"region0": {
"address": "0x8000_0000",
"size": "0x10_0000_0000_0000"
}
},
"io": {
"address": "0",
"size": "0x8000_0000",
"items": {
"io0": {
"address": "0x0",
"size": "0x1_0000"
},
"io1": {
"address": "0x200_c000",
"size": "0x5ff_4000",
"test_access": "available"
},
"htif": {
"address": "0x7000_0000",
"size": "0x10"
}
}
}
},
"features": {
"rv64": {"supported": true, "enabled": true, "randomize": 100},
"i": {"supported": true, "enabled": true, "randomize": 100},
"m": {"supported": true, "enabled": true, "randomize": 100},
"a": {"supported": true, "enabled": true, "randomize": 100},
"f": {"supported": true, "enabled": true, "randomize": 100},
"d": {"supported": true, "enabled": true, "randomize": 100},
"c": {"supported": true, "enabled": true, "randomize": 100},
"h": {"supported": true, "enabled": true, "randomize": 100},
"v": {"supported": true, "enabled": false, "randomize": 100},
"u": {"supported": true, "enabled": true, "randomize": 100},
"s": {"supported": true, "enabled": true, "randomize": 100}
},
"test_generation": {
"secure_access_probability": 30,
"secure_pt_probability": 0,
"a_d_bit_randomization": 0,
"pbmt_ncio_randomization": 0
}
}
Validation Rules
Address Format:
- Addresses can use underscore separators for readability: "0x8000_0000"
- Both string and integer formats are supported
- Hexadecimal strings must start with "0x"
Size Format: - Sizes follow the same format rules as addresses - Must be positive values
Memory Layout: - DRAM regions must not overlap - I/O items must fit within the parent I/O region - All addresses must be valid for the target architecture
Feature Dependencies:
- Some extensions have dependencies (e.g., d requires f)
- Architecture width (rv32/rv64) affects address space limits