Amlogic S905W/S905D/S912/S905X/S905L/S805X/S805Y/S905Z

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Amlogic S905W/
S905D/
S905X/
S905L/
S805X/
S805Y/
S905Z
Amlogic S905X chip
Amlogic S905X chip
Manufacturer Amlogic
Name S905W/
S905D/
S905X/
S905L/
S805X/
S805Y/
S905Z
Codenames GXL
Architecture aarch64
CPU 4x 1.2/1.5/2 GHz Cortex-A53
GPU Mali-450 MP3
Year 2016
Process 28nm
Mainline yes
Community Page https://linux-meson.com/
Components
CPU
Works
UART
Works
Storage
Partial
USB
Works
Display
Works
GPU
Works
Pinctrl
Works
I²C
Works
SPI
Audio
Works
Video
Partial
Thermal
Works
NPU
Suspend
Ethernet
Amlogic S912
Manufacturer Amlogic
Name S912
Codenames GXM
Architecture aarch64
CPU 8x2Ghz Cortex-A53
GPU Mali-450 MP3
Year 2016
Process 28nm
Mainline yes
Community Page https://linux-meson.com/
Components
CPU
Works
UART
Works
Storage
Partial
USB
Works
Display
Works
GPU
Works
Pinctrl
Works
I²C
Works
SPI
Audio
Works
Video
Partial
Thermal
Works
NPU
Suspend
Ethernet


Amlogic S905W/S905D/S912/S905X/S905L/S805X/S805Y/S905Z SoCs are media player SoCs mainly used in Android set-top boxes. S912 is the only chip in the GXM Amlogic SoC family but the rest of them are part of GXL.However,they are very similar to each other .Here are the differences between them:

High-end Chip :

  • S905W : It capable of hardware decoding 4Kp60/30 H.265/H.264, VP9 and has 100M ethernet phy,1G ethernet mac,VP9 hardware , camera interface and TS inputs,1 X cpu cluster that contain 4 X Cortex-A53@2GHZ
  • S905D : Seem to identical to S905W , but support ISO7816 IN for DVB
  • S912 : Identical to S905D but instead of having one cluster it has 2 thus it has 8 X Cortex-A53@2GHZ in total

Mid-range Chip:

  • S905X : A slightly lower clock variant (CPU cores up to 1.5 GHz) of S905W
  • S905L : Identical to the S905X except for the lack of VP9 decoding, camera interface and TS inputs.

Low-end Chip:

  • S805X : A slightly lower clocked (CPU cores up to 1.2 GHz) and can only decode 1080p60/30 H.265/H.264 , VP9.It is a stripped down variant of S905X.
  • S805Y : Used in Xiaomi Mi TV Stick (xiaomi-aquaman), identical to the S805X.

Unknown :

There are also -h variant of Amlogic S905W/S905D/S905X/S905L/S805X/S805Y/S905Z. it is a variant of the soc that has include Dolby/DTS licenses.

Devices

Device Codename Chipset Mainline booting
Amazon Fire TV 3 amazon-needle Amlogic S905Z No
Amediatech X96 Mini amediatech-x96-mini Amlogic S905W Y Yes
Beelink gt1 (Ultimate) beelink-gt1 Amlogic S912 Y Yes
HomeX X1 AK1708m-16 Amlogic S905X No
Libre Computer AML-S805X-AC-V1.0 librecomputer-lafrite Amlogic S805X Y Yes
Libre Computer AML-S905X-CC-V1.0 librecomputer-lepotato Amlogic S905X Y Yes
OTT OTT X96 ott-x96 Amlogic S905X Y Yes
Xiaomi Mi Box 3 xiaomi-once Amlogic S905X-H Y Yes
Xiaomi Mi TV Stick xiaomi-aquaman Amlogic S805Y No

Different Between GXM and GXL

<narmstrong> S912 is basically gxl with a second cpu cluster, so I think the gxl bl2 would work but bl31 should be fixed to bring up the second cluster
<f_> Pretty much..
<narmstrong> It’s even dumber that you think, the second cpu cluster hasn’t a dedicated pll, it uses the fixed 1ghz system pll fixed divider… <

See Irc log from linux-amlogic

Boot process

See: Amlogic#Boot process

BL1 looks for a header (named @AML header) at different offsets depending on the storage media:

  • On an SD card or eMMC: offset 512 (512 bytes completly ignored by BL1), header and checksum from offset 528 to 623, payload at offset 4608 onwards

There's a bug where, because of the zero-offset requirement on eMMC, MBR structures cannot coexist, requiring tweaks to allow an MBR parition table to coexist. Further reading: https://github.com/LibreELEC/amlogic-boot-fip/pull/8

BL2 is signed by using a proprietary utility from Amlogic called aml_encrypt_gxb, but there's a replacement called gxlimg. See https://github.com/repk/gxlimg. It has been confirmed to work on Libre_Computer_AML-S905X-CC-V1.0_(librecomputer-lepotato)

Then BL2 loads the following:

  • BL30/SCP_BL2: System control processor firmware
  • BL31: EL3 Runtime Software
  • BL32: OPTEE (optional)
  • BL33: U-Boot

All bootloader stages except U-Boot are proprietary. BL31 can be replaced with upstream Arm Trusted Firmware-A. There's also an ongoing effort led by User:F to reverse-engineer BL2 and port U-Boot SPL.

Status

GPU and hardware acceleration

Works.

IR RX

Works

Audio

S/PDIF audio works, but HDMI is untested

X11

Works fine. A custom configuration file is needed else it crashes (included).

See also

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