CAM, FreeBSD, GSoC, mmccam, RTEMS, SDIO

Backporting MMCCAM/SDIO framework to FreeBSD head 642b174dadd

My phase 2, GSoC objectives includes Backporting the current(rev: d6756a3ac8 ) MMCCAM framework to FreeBSD head 642b174dadd and then importing it to RTEMS. This post mainly concerns with intricacies and workarounds during the backporting process. Backporting is a process that enables old kernels run a latest driver. MMCCAM framework is one such enhancement in the past few months that enables FreeBSD to talk to devices behind the SDIO bus. It’s a major architectural change, that enables further…

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Benchmark, FIO, GSoC, RTEMS, Software

[GSoC Phase-1] Porting FIO to RTEMS

Hi all, This post covers most of my learnings during phase one of GSoC with RTEMS. My main goal of phase 1 was to port an IO benchmark to RTEMS. Towards this, various benchmarks were compared and fio was finalized for the import. FIO is a pretty much widely accepted and highly configurable IO benchmarking tool, which supports a number of large number of different OS and now RTEMS is among one of them. Following were the…

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Benchmark, Bonnie++, FIO, FreeBSD, GSoC, IOZONE, RTEMS, Software

Comparing IO benchmarks: FIO, IOZONE and BONNIE++

IO benchmarks refer to the computerized test for measuring various properties of a IO device under various conditions. Various properties includes Read/Write speed, IOPS, seek time etc and various conditions refers to random/sequential reads/writes, block size used by the filesystem, buffer cache size etc. There are various IO benchmarks available online, but the top 3 opensource IO benchmarks, in my view includes FIO, IOZONE and BONNIE++. There are several pros and cons for each of them, which…

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Benchmark, CAM, File system, FreeBSD, GSoC, mmccam, SDIO

microSD Card benchmarking on BeagleBone Black

Hi all, I have been recently involved in benchmarking two different device drivers of FreeBSD ,namely SDHCI and the SDIO driver to compare their relative performance under different circumstances. Here, I will summarize my results, possible conclusions and the benchmarking procedure. Before moving towards benchmarking, i’d prefer going through this article. It really good and provides a great overview of how data is transferred to disk, different APIs available. This will surely help you selecting options for…

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GSoC

GSoC Project Introduction : Importing SDIO stack and Benchmarking

Hi all, This post is basically an introduction of my GSoC 2018 project under RTEMS. It marks the beginning of a series of blog posts that will be put on ( under the tag ‘GSoC’ ) for documenting my work throughout the time span. Before moving on, I would like to thank RTEMS project and Google for giving me this opportunity of working on a highly fruitful Open source project, whose proposal can be found here ,under…

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ARM, CAM, FreeBSD, mmccam, SDIO, Software

Building FreeBSD’s SDIO driver for BeagleBone Black

Hi all, This post mainly concern with building FreeBSD’s SDIO driver for BeagleBone Black by cross compiling it on AMD platform. I had few unresolved issues with the master branch of current FreeBSD tree. So, for this i used another unofficial branch: https://github.com/kibab/freebsd/tree/mmcam-new . It does have the required KERNCONF file with stable SDIO driver. A lot of steps below are similar to the one given on: https://forums.freebsd.org/threads/cross-compiling-beaglebone-on-amd64.64718/#post-384835  with slight but inevitable changes. Procedure:  Before proceeding you…

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FreeBSD, Software

Setting up FreeBSD environment on virtualbox

Hi all, In this post we will review the procedure of setting up FreeBSD environment on virtualbox along with setting up Internet on the guest OS(this was pretty tricky!).BTW, my host OS is Ubuntu 14.04 So, i am assuming you have already installed virtualbox as per your host OS and has downloaded the FreeBSD amd64 iso image(If not you can do it from here and extract it appropriately to get a .iso file. Installing FreeBSD on virtualbox…

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File system, Hardware, NAND/NOR

Effect of file-system on sd card’s performance

I had a task to compare different protocols( and their different implementations) like SD, SPI, SDIO(in FreeBSD’s MMCCAM implementation) by accessing SD Card. Now, for unbiased comparison, i must eliminate file system type in sd card from the equation. In this blog post, i’ll discuss/share my findings about how file-system on a card(SD and MMC) affect its performance. So, let’s start with a very quick introduction to some basic concepts: Introduction MMC- Multimedia Card is a memory…

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CAM, FreeBSD, mmccam, SDIO, Software

Implementing a MMC/SD/SDIO stack using CAM framework(Part 2)

Hi, In the next part lets look at other files which makes up the SDIO stack within mmccam framework. Please have  a look at previous part for more info: http://uditagarwal.in/index.php/2018/03/19/implementing-a-mmc-sd-sdio-stack-using-cam-framework/ mmc_sdio.c

sdio_fill_mmcio_rw_direct is basically a wrapper for CMD_52 that’s needed to read/write directly into mmc register R5. Remember that register R5 in mmc, is used for RCA(Relative card address) management. It’s right time now to talk about different command types of SD/MMC/SDIO: broadcast commands (bc), no…

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CAM, FreeBSD, Hardware, mmccam, SDIO, Software

Detailed SDIO protocol Implementation

Reference: Wikipedia, https://www.sdcard.org/developers/overview/sdio/sdio_spec/Simplified_SDIO_Card_Spec.pdf  SDIO cards are intended to provide high speed data Input/Output on our regular sd card slot. SDIO cards are compatible with any sd card slot and will not cause any physical damage to the host if it’s not compatible with SDIO. When SDIO is plugged in a SDIO compatible host, in its early stage it is in low power mode and consumes very little current. Host identifies the SDIO card ,it’s power requirement, it’s…

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