Group: Hardware/Computers/Tablets

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John's braindump:

The FSF wants to do something to make a completely free tablet a reality.

An important step here is the video hardware. Some chipsets have free drivers, but rely on proprietary firmware. The FSF is considering a project to replace this proprietary firmware with free firmware.

1) We should choose a chipset that is very new, so that the product will still be useful for some time.

2) We should choose something that is used in many different products, if possible.

3) We should choose something that is present in products that have the best chance of being fully free otherwise. If it has a USB port, it can get free wifi that way, for example.

4) We should pursue better relations with manufacturers to get documentation at least, or in the best case to convince them based on our reverse engineering success to do the right thing from the beginning.

We may start with an eink reader, because it's much easier to do, it would be a big step, and it would build momentum toward doing a full tablet.

We are chatting about the project in #fsf-tablet on irc.oftc.net.

About Lima: https://fosdem.org/2013/schedule/event/operating_systems_open_arm_gpu/

comparaison of chipsets

Wifi

Recent enough chipsets/drivers that could be used are:

  • ath9k (mini-pcie) if the SOC has a PCI lane
  • ath9k-htc (USB) The think penguin version requires 500mA, no device will work with known Replicant tablets supporting only 100mA or 200mA: AR9271 itself needs ~200mA, Unex DNUA-93F (rebranded by Tehnoetic and Think Penguin?) can use 300mA

SOC

Manufacturer SOC GPU Bootloader status USB host (mini)PCI(e) possible? Minimum quantity required
Texas instruments DM370(like omap3 but higher speed) Powervr good (free software unsigned possible) Yes Seem not ?
Texas instruments omap4 Powervr good (free software unsigned possible) Yes Seem not ?
Allwinner Tech A31 Powervr good (free software unsigned possible) Yes ? ?
Allwinner Tech A10,A10s,A13,A20 Mali good (free software unsigned possible, requires SD-card) Yes ? ?
Samsung Exynos 3 Single -> Exynos 5 dual Mali bad (part of it is software, non-free and signed on all known devices) Yes ? ?
Samsung Exynos 5 Octa Powervr ? ? ? ?
Freescale I.MX6 Vivante, partially supported by etna_viv; VPU with nonfree firmware unknown, was good on previous versions of the chip Yes Yes ?
Ingenic JZ4760 Vivante GC200 Free Yes ? 1

see also