Re: understanding the role/relationship of the firmware and driver in case of Wi-Fi adapters
Bob, thank you for this exhaustive reply! 1) Are there Wi-Fi adapters which do not need firmware? I guess there are if manufacturer does not use semi-general purpose hardware? 2) Is the RAM built into the Wi-Fi card chipset? If I inspect my Ralink W-Fi card, which loads the 4096 byte /lib/firmware/rt2870.bin firmware file once the interface is brought up, then I don't see a separate RAM chip: https://www.dropbox.com/s/9z5rir3byfr9sg2/TEW-624UB-front.png https://www.dropbox.com/s/8p4iw8dpnfiphqb/TEW-624UB-back.png So in this case the RAM which stores the rt2870.bin firmware file is probably part of the RT2870F chip? regards, Martin 2013/1/2 Bob Proulx b...@proulx.com: Martin T wrote: some Wi-Fi adapters(for example Intel ipw2200 family and many Ralink cards) require both firmware and drivers in order to operate properly. Yes. 1) As I understand, firmware is usually a closed-source binary image provided by Wi-Fi card manufacturer? Yes. And because of this it doesn't meet the Debian Free Software Guidelines and can't be part of Debian. Packages of this firmware can only go in the non-free repository. 2) What happens with the firmware when card becomes operational? I mean by definition it should be written to device non-volatile memory(for example flash memory), but I doubt that this is the case for Wi-Fi adapters.. Or is it? No. The image is simply loaded into the adapter's ram. After the device loses power the memory evaporates. When power is applied again the device is once again blank or back to the default power on state and the firmware must be loaded again. 3) Last but not least, which aspects are controlled by Wi-Fi card firmware and what role plays the Wi-Fi adapter driver? Most devices today are designed using semi-general purpose hardware which includes a firmware part to configure and program the device. Vendors do this because it allows them to ship hardware early and to fix hardware bugs by making changes to the firmware later. They can do this very late and often after shipping the product. They simply update the device driver and put it on their web site and their customers load the new driver. This can effectively fix an incorrectly designed piece of hardware in the field. And that is why vendors like to design devices that use a firmware component. That they are programmable does not make them a computer. They are usually simply logic devices with memory to program the operation of them. There are various techniques such as state machines implemented with FPGAs and so forth. Programmable state machines almost always play a huge part in any electronic chip design. There isn't a simple rule that says every adapter behaves a certain way and the firmware does a certain thing on every one of them. Every vendor designs their device independently. Every one of them may be different. Which makes it hard to produce a generally correct answer. All that can really be said is that the firmware is used by the device to set itself up for the operation it was designed to do. After loading the device firmware then the kernel device driver has the task of interacting with the device. It provides the software layer that translates between a physical hardware device and the kernel's software. Bob Speaking as a past chip designer. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/cajx5yvfdncsygshjs-1dp6uqun7ampcbc7jurzcxlhjlp8x...@mail.gmail.com
Re: understanding the role/relationship of the firmware and driver in case of Wi-Fi adapters
Martin T m4rtn...@gmail.com wrote: 1) Are there Wi-Fi adapters which do not need firmware? I guess there are if manufacturer does not use semi-general purpose hardware? I guess: not anymore. The last ones I saw without firmware were in the 11MBit era of wifi. All the new ons with 54Mbit and up are actually so-called software defined radios which are not more than a multi-purpose HF chip plus a controller which can be used to programm (nearly) any functionality into the hardware. I remember some of the Atheros-based cards were/are very sought after by amateur radio operators and hackers (in the white hat meaning of the word) because you can reprogramm them to be _any_ type of radio in the frequency range from 800MHz to 6000MHz. 2) Is the RAM built into the Wi-Fi card chipset? If I inspect my Ralink W-Fi card, which loads the 4096 byte /lib/firmware/rt2870.bin firmware file once the interface is brought up, then I don't see a separate RAM chip: https://www.dropbox.com/s/9z5rir3byfr9sg2/TEW-624UB-front.png https://www.dropbox.com/s/8p4iw8dpnfiphqb/TEW-624UB-back.png So in this case the RAM which stores the rt2870.bin firmware file is probably part of the RT2870F chip? It would seem that way, yes. Grüße, Sven. -- Sigmentation fault. Core dumped. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/49dga82gl...@mids.svenhartge.de
understanding the role/relationship of the firmware and driver in case of Wi-Fi adapters
Hello, some Wi-Fi adapters(for example Intel ipw2200 family and many Ralink cards) require both firmware and drivers in order to operate properly. 1) As I understand, firmware is usually a closed-source binary image provided by Wi-Fi card manufacturer? 2) What happens with the firmware when card becomes operational? I mean by definition it should be written to device non-volatile memory(for example flash memory), but I doubt that this is the case for Wi-Fi adapters.. Or is it? 3) Last but not least, which aspects are controlled by Wi-Fi card firmware and what role plays the Wi-Fi adapter driver? regards, Martin -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/cajx5yvf1qvgftwoviaoo3hejkf3sjzokvkz7f7ocnrtmsd9...@mail.gmail.com
Re: understanding the role/relationship of the firmware and driver in case of Wi-Fi adapters
Martin T wrote: some Wi-Fi adapters(for example Intel ipw2200 family and many Ralink cards) require both firmware and drivers in order to operate properly. Yes. 1) As I understand, firmware is usually a closed-source binary image provided by Wi-Fi card manufacturer? Yes. And because of this it doesn't meet the Debian Free Software Guidelines and can't be part of Debian. Packages of this firmware can only go in the non-free repository. 2) What happens with the firmware when card becomes operational? I mean by definition it should be written to device non-volatile memory(for example flash memory), but I doubt that this is the case for Wi-Fi adapters.. Or is it? No. The image is simply loaded into the adapter's ram. After the device loses power the memory evaporates. When power is applied again the device is once again blank or back to the default power on state and the firmware must be loaded again. 3) Last but not least, which aspects are controlled by Wi-Fi card firmware and what role plays the Wi-Fi adapter driver? Most devices today are designed using semi-general purpose hardware which includes a firmware part to configure and program the device. Vendors do this because it allows them to ship hardware early and to fix hardware bugs by making changes to the firmware later. They can do this very late and often after shipping the product. They simply update the device driver and put it on their web site and their customers load the new driver. This can effectively fix an incorrectly designed piece of hardware in the field. And that is why vendors like to design devices that use a firmware component. That they are programmable does not make them a computer. They are usually simply logic devices with memory to program the operation of them. There are various techniques such as state machines implemented with FPGAs and so forth. Programmable state machines almost always play a huge part in any electronic chip design. There isn't a simple rule that says every adapter behaves a certain way and the firmware does a certain thing on every one of them. Every vendor designs their device independently. Every one of them may be different. Which makes it hard to produce a generally correct answer. All that can really be said is that the firmware is used by the device to set itself up for the operation it was designed to do. After loading the device firmware then the kernel device driver has the task of interacting with the device. It provides the software layer that translates between a physical hardware device and the kernel's software. Bob Speaking as a past chip designer. signature.asc Description: Digital signature
