Qualcomm: Difference between revisions

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==Controversial Practices==

=== Restrictions on software modifications ===

===Restrictions on software modifications===

Qualcomm employs mechanisms in their Snapdragon SoCs that prevent users from running their own code or modifying firmware or operating system code on their devices. Such mechanisms include Secure Boot where each boot stage authorizes the next stage establishing a "chain of trust". On power-on, the SoC executes the Primary Boot Loader (PBL), stored in immutable read-only memory (ROM) etched in the silicon die making it physically impossible to modify. PBL loads and authorizes the eXtended Boot Loader (XBL), which in turn loads and authorizes the next stage which can be another bootloader or the operating system, all of which are stored in rewritable flash memory. The SoC contains a set of one-time programmable (OTP) electronic fuses within the SoC, which store cryptographic signing keys along with other parameters such as enabling Secure Boot and debugging flags. The signing keys are generated by Qualcomm and the device OEM and are used by the various boot stages to verify images loaded from flash memory. The keys are not provided to the end user, preventing any modifications to the software images. A technical paper by Qualcomm<ref>[https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/secure-boot-and-image-authentication.pdf Secure Boot and Image Authentication Technical Overview], ''Qualcomm Technologies Inc.'', Retrieved 2025-10-08</ref> details the Secure Boot mechanism and clarifies the entities allowed to authorize software running on the end device:

Qualcomm employs mechanisms in their Snapdragon SoCs that prevent users from running their own code or modifying firmware or operating system code on their devices. Such mechanisms include Secure Boot where each boot stage authorizes the next stage establishing a "chain of trust". On power-on, the SoC executes the Primary Boot Loader (PBL), stored in immutable read-only memory (ROM) etched on the silicon die making it physically impossible to modify. PBL loads and authorizes the eXtended Boot Loader (XBL), which in turn loads and authorizes the next stage which can be another bootloader or the operating system, all of which are stored in rewritable flash memory. The SoC contains a set of one-time programmable (OTP) electronic fuses within the SoC, which store cryptographic signing keys along with other parameters such as enabling Secure Boot and debugging flags. The signing keys are generated by Qualcomm and the device OEM and are used by the various boot stages to verify images loaded from flash memory. The keys are not provided to the end user, preventing any modifications to the software images.

A technical paper by Qualcomm<ref>[https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/secure-boot-and-image-authentication.pdf Secure Boot and Image Authentication Technical Overview], ''Qualcomm Technologies Inc.'', Retrieved 2025-10-08</ref> details the Secure Boot mechanism and clarifies the entities allowed to authorize software running on the end device:

<blockquote>The OTP eFuse configuration dictates the device custodian, who is commonly referred as the Original Equipment Manufacturer (OEM). The device OEM takes control of the device mutable software by loading a configuration file with their custom fuse values. The configuration file sets the fuses that enable secure boot and stores a cryptographic hash of the manufacturer public key certificate in the fuses reserved for it.

Moreover, the immutable hardware has the ability to include the OEM fuse configuration in platform key derivations along with hardware secrets provisioned into the chip by Qualcomm Technologies and the device OEM. Secure boot restricts all keys with these bindings to software signed by that OEM and to them alone. One of the guiding principles of Qualcomm Secure boot is that no software runs without an authorization from the OEM.</blockquote>The device OEM is set as the "device custodian" which controls the software that may run on the device. Further text describes other entities that may have a hand in authorizing software:

@@ Line 14: / Line 14: @@
 ==Controversial Practices==
-=== Restrictions on software modifications ===
+===Restrictions on software modifications===
-Qualcomm employs mechanisms in their Snapdragon SoCs that prevent users from running their own code or modifying firmware or operating system code on their devices. Such mechanisms include Secure Boot where each boot stage authorizes the next stage establishing a "chain of trust". On power-on, the SoC executes the Primary Boot Loader (PBL), stored in immutable read-only memory (ROM) etched in the silicon die making it physically impossible to modify. PBL loads and authorizes the eXtended Boot Loader (XBL), which in turn loads and authorizes the next stage which can be another bootloader or the operating system, all of which are stored in rewritable flash memory. The SoC contains a set of one-time programmable (OTP) electronic fuses within the SoC, which store cryptographic signing keys along with other parameters such as enabling Secure Boot and debugging flags. The signing keys are generated by Qualcomm and the device OEM and are used by the various boot stages to verify images loaded from flash memory. The keys are not provided to the end user, preventing any modifications to the software images. A technical paper by Qualcomm<ref>[https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/secure-boot-and-image-authentication.pdf Secure Boot and Image Authentication Technical Overview], ''Qualcomm Technologies Inc.'', Retrieved 2025-10-08</ref> details the Secure Boot mechanism and clarifies the entities allowed to authorize software running on the end device:
+Qualcomm employs mechanisms in their Snapdragon SoCs that prevent users from running their own code or modifying firmware or operating system code on their devices. Such mechanisms include Secure Boot where each boot stage authorizes the next stage establishing a "chain of trust". On power-on, the SoC executes the Primary Boot Loader (PBL), stored in immutable read-only memory (ROM) etched on the silicon die making it physically impossible to modify. PBL loads and authorizes the eXtended Boot Loader (XBL), which in turn loads and authorizes the next stage which can be another bootloader or the operating system, all of which are stored in rewritable flash memory. The SoC contains a set of one-time programmable (OTP) electronic fuses within the SoC, which store cryptographic signing keys along with other parameters such as enabling Secure Boot and debugging flags. The signing keys are generated by Qualcomm and the device OEM and are used by the various boot stages to verify images loaded from flash memory. The keys are not provided to the end user, preventing any modifications to the software images.
+A technical paper by Qualcomm<ref>[https://www.qualcomm.com/content/dam/qcomm-martech/dm-assets/documents/secure-boot-and-image-authentication.pdf Secure Boot and Image Authentication Technical Overview], ''Qualcomm Technologies Inc.'', Retrieved 2025-10-08</ref> details the Secure Boot mechanism and clarifies the entities allowed to authorize software running on the end device:
 <blockquote>The OTP eFuse configuration dictates the device custodian, who is commonly referred as the Original Equipment Manufacturer (OEM). The device OEM takes control of the device mutable software by loading a configuration file with their custom fuse values. The configuration file sets the fuses that enable secure boot and stores a cryptographic hash of the manufacturer public key certificate in the fuses reserved for it.
 Moreover, the immutable hardware has the ability to include the OEM fuse configuration in platform key derivations along with hardware secrets provisioned into the chip by Qualcomm Technologies and the device OEM. Secure boot restricts all keys with these bindings to software signed by that OEM and to them alone. One of the guiding principles of Qualcomm Secure boot is that no software runs without an authorization from the OEM.</blockquote>The device OEM is set as the "device custodian" which controls the software that may run on the device. Further text describes other entities that may have a hand in authorizing software: