nitrox_tool's Introduction

Nitrox tool

An assembler and disassembler for microcode of Cavium (now Marvell) Nitrox crypto accelerators.

Getting Started

$ nitrox.py -d CNPx-MC-BOOT-2.00

Everything is big-endian unless indicated otherwise.

All Except O8x:

1 byte: type
31 bytes: version (ASCII, zero padded)
4 bytes: number of instructions (size varies)
4 bytes: data length in bytes (multiple of 8)
code section
- old format (4 bytes per instruction): 15 bits IRAM address, 1 bit parity, 16 bits instruction
- new format (2 bytes per instruction): 16 bits instruction (little-endian on Nitrox V)
align to 16 bytes
data section
align to 16 bytes
256 bytes: signature (unknown format, unused)
copyright notice (optional, unused)

O8x:

8x 16-bit general purpose registers, r0..r7
16x 16-bit auxiliary registers (Nitrox 1/Lite), a0..b7
32x 16-bit auxiliary registers (Nitrox PX/3), a0..d7 (d7 is only used on Nitrox 3 and newer)
sign flag (result has bit 15 set)
zero flag (result is zero)
32-entry call stack
peculiarities:
- no unconditional jump instruction
- shift instructions on Nitrox 1/Lite are very limited: shr1, shr3, shl3
- no way to directly load immediate into upper 8 bits on Nitrox 1/Lite

Many instructions have:

how much SRAM is there exactly? Harvard or Von Neumann architecture? is self-modifying code possible?
figure out how to configure/program the hardware blocks outside the microcontroller (including DMA and SRAM)
why are there two different return instructions?
refactor
add a little bit of macro support
how to recover from a call stack overflow? (exceptions?)
Nitrox II (no products found yet)
ThunderX2 (no microcode found yet)

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