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For people not familiar with the industry or the issue, compare the documentation available for the broadcom processor in the popular raspberry pi 2 https://gi
by pawadu 10y ago
For people not familiar with the industry or the issue, compare the documentation available for the broadcom processor in the popular raspberry pi 2
https://github.com/raspberrypi/documentation/tree/master/hardware/raspberrypi/bcm2836 https://github.com/raspberrypi/documentation/tree/master/har...
and that of the Allwinner A64 in the far less common "Banana Pi":
https://github.com/OLIMEX/OLINUXINO/tree/master/HARDWARE/A64-OLinuXino/PDF https://github.com/OLIMEX/OLINUXINO/tree/master/HARDWARE/A64...
As you can see, the Broadcom documentation is non-existent, with the exception of a tiny document created by a third party.
- revelation 10y agoAll of the Allwinner stuff is equally useless, not sure what you are seeing there. Some registers for the PMIC, hurray. Electronic chip manufacturers are scum, amoral leeches on a thriving ecosystem that is powered by largely opensource software.
- userbinator 10y agoDid you take a look at the Allwinner A64 User Manual? That alone beats anything Broadcom has ever released for the RPi.
- cheiVia0 10y agohttp://www.broadcom.com/blog/chip-design/android-for-all-broadcom-gives-developers-keys-to-the-videocore-kingdom/ http://www.broadcom.com/blog/chip-design/android-for-all-bro... Also, Broadcom is paying someone to write an open driver for the RPi GPU. They are literally the first company to do open GPU drivers for ARM-related GPUs.
- kogepathic 10y ago> They are literally the first company to do open GPU drivers for ARM-related GPUs. No, the Raspberry Pi has a Broadcom GPU (VideoCore IV). ARM-related GPUs would be the Mali line, of which there is already an open-source effort (lima). So Broadcom is paying someone to write an open driver for their own GPU. This doesn't benefit anyone else in the ARM ecosystem in the slightest. It's a Broadcom move for Broadcom's benefit alone.
- dezgeg 10y ago> So Broadcom is paying someone to write an open driver for their own GPU. This doesn't benefit anyone else in the ARM ecosystem in the slightest. I would not be so cynical. It'd be quite unlikely that properly upstreamed Mesa and/or kernel code wouldn't lead to any idea sharing or refactoring/optimization of the common code used by all drivers.
- revelation 10y agoIt's a generic ARM, there is a reason for stuff like CMSIS, they are all the same old IP.
- pawadu 10y agoI think you are misunderstanding the situation. Both chips contain a CPU from ARM, so far so good. For the rest of the chip allwinner uses modern, well documented and battle proven components mainly from ARM. To save a few cents, broadcom uses undocumented home-gown crap that nobody understands. Just look at their crazy interrupt controller that can not do true multicore - which probably is one of the reasons pi3 is overheating.
- revelation 10y agoThat's what I'm saying. The reason there is register documentation for that Allwinner CPU is because it's a bog standard ARM. They pretty much just copied it. That doesn't really speak to Allwinners open-source embracing nature.
- pawadu 10y agoWell, they paid good money to license the ARM components and their documentation actually adds to the standard ARM documentation by filling in some device-specific gaps. But not everything here comes from ARM, look for example at their power management documentation which is (as always) proprietary. Can you point me to the same information in the broadcom datasheet?
- deleted 10y ago[deleted]