Chester-Gillon’s gists

Chester-Gillon / AXI_Interconnect_and_SmartConnect_dont_support_address_remap.md

Last active December 7, 2025 18:43

AXI Interconnect and SmartConnect don't support address remap

Have been using AXI Interconnect and SmartConnect in Vivado block designs to map multiple different peripherals to access via PCIe, without previously finding issues.

For the U200_100G_ether_simplex_tx went to add a second CMAC block.

The AXI SmartConnect assignments in the /xdma_0/M_AXI_LITE address space were:

Master Segment Name	Slave Segment	Offset	Range
SEG_cmac_usplus_0_Reg	/cmac_usplus_0/s_axi/Reg	0x0000	8K
SEG_axi_gpio_0_Reg	/axi_gpio_0/S_AXI/Reg	0x2000	8K
SEG_system_management_wiz_0_Reg	/system_management_wiz_0/S_AXI_LITE/Reg	0x4000	8K

Chester-Gillon / Home_lab_100G_Ethernet_switches.md

Last active December 7, 2025 16:10

Home lab 100G Ethernet switches

0. Introduction

Notes about 100G Ethernet switches for a home lab, looking for either:

Cheap low port count new switches.
Available second hand switches with possibly more ports than required.
Options for mixing some low speed ports, as have some other 10G devices.

Found on Reddit "Cheap" 100G switches, pros and cons of each option? for initial suggestions.

1. Mikrotik CRS504-4XQ-IN

Chester-Gillon / open-nic_on_Alveo_U200.md

Last active December 6, 2025 10:36

open-nic on Alveo U200

0. Introduction

Contains notes about using the open-nic project on an Alveo U200.

1. Clone projects

1.1 Cloned tagged projects via open-nic, but doesn't support the U200

Using SmartGit cloned https://github.com/Xilinx/open-nic into ~/U200_open-nic/open-nic.

Chester-Gillon / Xilinx_SSI_bitstream_format.md

Last active September 14, 2025 17:23

Xilinx Stacked Silicon Interconnect (SSI) bitstream format

0. Introduction

xilinx_7_series_bitstream.c was originally written for Xilinx 7 series devices, before subsequently adding support for Xilinx UltraScale and UltraScale+ devices.

1. 7K160T has no unprocessed data at the end of the bit stream

The 7K160T doesn't use SSI.

Convert the bit to bin file, to remove the header so the contents of the file is word aligned:

Chester-Gillon / Notes_about_AMD_Alveo_U200_Data_Center_Accelerator_Card_(Active).md

Last active November 29, 2025 16:40

Notes about AMD Alveo U200 Data Center Accelerator Card (Active)

0. Introduction

This contains notes about using a AMD Alveo™ U200 Data Center Accelerator Card (Active)

The card was second hand and has been installed in slot 2 on a HP Z6 G4 workstation, with the 8-pin aux power cable connected. This is a PCle3 x16 slot connected to the CPU. The slot 2 BIOS settings were the following, with Hot Plug enabled since had previously used other FPGA boards in the slot:

Slot 2 PCI Express x16
	Disable
	*Enable
Slot 2 Option Rom Download

Chester-Gillon / Notes_about_Alibaba_Cloud_AS02MC04_NIC_Card.md

Last active September 28, 2025 14:01

Notes about Alibaba Cloud AS02MC04 NIC Card

0. Introduction

This contains notes about using the Xilinx FPGA development Kintex ku3p ultra scale + development XCKU3P-FFVB676. The branding is Alibaba Cloud with part number AS02MC04.

Read the Device DNA over JTAG and using AMD Device Lookup reports:

SpeedGrade1E

Device	XCKU3P
Package-Pin	FFVB676
Revision Code	AAZ

Chester-Gillon / MATLAB_parallel_pool_maximum_RSS.md

Last active July 13, 2025 13:22

MATLAB parallel pool maximum RSS

0. Introduction

Notes about trying to track the maximum RSS (Resident Set Size) for a MATLAB parallel pool.

This is using: Ubuntu 24.04.2 LTS with the following installed:

>> ver
-----------------------------------------------------------------------------------------------------------
MATLAB Version: 9.8.0.1873465 (R2020a) Update 8
MATLAB License Number:

Chester-Gillon / AlmaLinux_10_initial_look.md

Last active June 28, 2025 20:57

AlmaLinux 10 initial look

0. Introduction

Some notes about an initial look at AlmaLinux 10. Downloaded live images from the links in How to download and write images

For testing copied the images to a MicroSD card. E.g.:

$ sha256sum -c CHECKSUM\(1\)
AlmaLinux-10.0-x86_64_v2-Live-GNOME.iso: OK

Chester-Gillon / HP_USB-C_to_RJ45_Adapter_G2.md

Last active May 18, 2025 18:45

HP USB-C to RJ45 Adapter G2 usage

0. Introduction

Contains some notes about use of a HP USB-C to RJ45 Adapter G2

1. HP Z4 G4 AlmaLinux 8.10

Using Kernel 4.18.0-553.51.1.el8_10.x86_64

The output of dmesg after plugged into a front panel USB-C port. There was a delay of several minutes before connected to an Ethernet switch and the following output ends with the link coming up:

Chester-Gillon / VFIO_DMA_mappings_behaviour_on_process_fork.md

Last active May 5, 2025 13:01

VFIO DMA mappings behaviour on process fork

0. Introduction

fork() Causes DMA Buffer in Physical Memory to Retain Stale Data on Subsequent Writes describes an issue with a forked process causing issues with memory for DMA. It wasn't clear what mechanism was being used to allocate the memory for DMA.

The test_dma_descriptor_credits program was modified with the option of spawning a child process to see if could replicate the issue when VFIO is used for DMA mappings.

Used the following FPGA designs, which exercise both the memory mapped and stream interface test functions:

dma_blkram (TEF1001)
XCKU5P_DUAL_QSFP_dma_stream_loopback
Nitefury Project-0 version 0x2