Category:Samsung Exynos

This page only contains some info, data and links regarding mainline on Exynos SoCs. If you want to mainline a device please follow the Mainlining guide.

Most Exynos ARM SoCs released up until 2014 are well supported in mainline linux. For arm64 Samsung rarely tried getting the code into mainline linux, and so very few SoCs are supported. The ARM64 Exynos SoCs that are at least somewhat supported include:

• Exynos5433
• Exynos7 (Early revision of Exynos7420 ^[1])
• Exynos7885
• Exynos850 (also known as Exynos3830)
• Exynos8895
• Exynos990
• ExynosAuto v9
• ExynosAuto v920
• Tesla FSD
• Category:Google Tensor SoC (also known as S5E9845)

There's been multiple ARMv7 SoCs that have had good support in the past, but currently don't:

• Exynos4415 (support dropped from mainline kernel)
• Exynos5260: SM-N750 Galaxy Note 3 Neo
• Exynos5410
• Exynos5800

Unfortunately Samsung does not release user manuals for their SoCs anymore. If you have an Exynos arm64 SoC that you want to mainline then a good start is to study the device tree and drivers for another already supported SoC and compare with the vendor kernel for that SoC, and then look at devicetree and drivers in vendor kernel for your SoC and try to "translate" it into mainline-acceptable format with the other SoC as reference. A good reference might be Exynos850, and it's vendor kernel. When writing your mainline device trees (and drivers), start small with just bare essentials and some way to get output from the device (pstore/ramoops, simple-framebuffer, serial debugging) to make sure that works before adding more parts.

Bootloaders

Devices released before 2020 use S-BOOT, which is based on U-Boot, and past 2020 use S-LK. There's some leaks of S-LK for 990 and 2300. S-BOOT/S-LK have some weird quirks though:

• On devices with the new-style DECON (past 2016), the HW_SW_TRIG_CONTROL bit needs to be set in order to allow the framebuffer to refresh
• On some revisions, CNTFRQ_EL0 is left unset. This means that you either have to set it either via the exynos-usbdl exploit, or hardcode the frequency in the timer node inside the SoC DT

Also, the bootloaders expects device trees in a certain format, and modifies the device tree before booting kernel. This is pretty inconvenient when testing mainline kernels, and so it is a good idea to use a secondary bootloader and boot mainline from it. U-boot does not support modern Exynos SoCs, but there are some other small bootloaders/kernel wrappers that can be used:

• uniloader, inspired by minimal_sboot_wrapper but with support for more Exynos variants and with more features
• minimal_sboot_wrapper, wrapper to make it possible to boot mainline kernels with Samsung's Sboot bootloader (made for Exynos 7885)

History

The first Exynos 4 CPUs were initially called S5PCxxx, like it's predecessors, but then renamed. For locating information it can therefore be good to know the old names.

• The oldest Exynos processor is Exynos 3110, also known as hummingbird, which was renamed from S5PC110. It has a Cortex-A8 core.
  • S5PV210, found in some development boards, is supposedly similar to Exynos 3110
• Exynos 4210, the first Exynos 4 CPU, was initially called S5PC210, and has two Cortex-A9 cores
  • S5PV310, found in some development boards, is supposedly similar to Exynos 4210
• Exynos 4412 was initially called S5PC220, based on strings in very old u-boot blobs from Samsung. It has four Cortex-A9 cores.

The Exynos 4x12 is likely codenamed Pega/Pegasus (the Exynos 4212 is referred to as the Pega-D, the Exynos 4412 is referred to as the Pega-Q and the Exynos 3250 is referred to as the Pega-W(?)). "PegasusQ" is also the name of the CPU governor used on some Exynos 4412 devices.

The common denominator for Exynos 4 seem to be that the SOC has only Cortex-A9 cores. Later devices have Cortex-A15 cores (and possibly Cortex-A9 cores as well) and were then called Exynos 5.

Samsung SoCs Page

See also

• https://exynos.wiki.kernel.org
• There are some article that may help to port mainline scattered around the device which has gotten mainline support.
• User:knuxify provides an article^[2] about how to bring up the display of lt01wifi, which may help to those who want to port dsi panels.
• PabloPL's repository contains branches related to Exynos 7420, 7580, 8890
• dsankouski's repository contains branches related to Exynos 7880
• VDavid003's repository contains branches related to Exynos 7885
• ivoszbg's repository contains branches related to Exynos 8895
• krzk's repository contains branches with several vendor (Samsung) kernel sources for many Exynos SoCs

References