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This page is WiP. Information may not be correct, or may not be universally applicable

Qualcomm is a semiconductors company, and one of the biggest manufacturers of smartphone and tablet SoCs.

Booting Procedure

Qualcomm ARM SoCs make use of several bootloaders, each of which initializes and/or checks some things and then passes on execution to the next stage in the boot chain. The final stage is whatever operating system runs on the SoC. There are slight differences between the boot chains for different SoCs, here is a triplet of charts showing the boot chains of relatively recent Qualcomm SoCs.

Qualcomm bootchain pre msm8974.png Qualcomm bootchain pre msm8996.png Qualcomm bootchain post msm8994.png

As you can see, the main change introduced in msm8974 is the merging of SBL1, which used to consist of three bootloaders, into one, and the main change introduced in msm8996 is support for the ABL UEFI bootloader - however, in some cases, aboot is still used. These charts are not necessarily exact representations of the boot chain on a specific SoC in a specific application, since modifications can be made by manufacturers by either replacing / editing one of the later links in the chain, or by adding more bootloader stages.

A more close examination of these bootloaders will follow.

Mainline SoCs

SoC Arch Year
Qualcomm MSM8916 aarch64 2014
Qualcomm MSM8939 aarch64 2014
Qualcomm MSM8953 aarch64 2016
Qualcomm MSM8974 armv7 2013
Qualcomm MSM8996 aarch64 2016
Qualcomm MSM8998 aarch64 2017
Qualcomm SDM630 aarch64 2017
Qualcomm SDM636 aarch64 2017
Qualcomm SDM660 aarch64 2017
Qualcomm SDM845 aarch64 2018
Qualcomm SM8150 aarch64 2019

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