Stmicroelectronics (grand Ouest) Sas

Stmicroelectronics (grenoble 2) Sas

Michel Jaouen

Loic Pallardy

Frederic Ruelle

Gilles Trottier

Stephane Le Roy

Ludovic Barre

Moise Gergaud

In accordance with an embodiment, a method for transaction between an application executed by a processor and a peripheral via a hardware abstraction layer includes: configuring the peripheral comprising writing a transaction configuration emitted by the application into configuration registers of the peripheral via the hardware abstraction layer; verifying compliance of the transaction configuration written in the configuration registers; and executing the transaction only when the transaction configuration written in the configuration registers is compliant based on the verifying.

Transaction process between an application and a device

In an embodiment a method for managing access rights of software tasks executed by a processing unit (CPU) using a cache memory containing execution data of the tasks in memory locations, each execution data having an attribute representative of a level of access right of the respective task, includes changing the attributes of the locations of the cache memory when the access rights of at least one task changes and retaining the execution data contained in the locations of the cache memory.

Method of managing access rights for software tasks executed by a microcontroller, and corresponding integrated circuit

In an embodiment a method includes compiling, by a processor in a compiling phase, a software program intended to be executed by the processor, the processor having secure and non-secure access right level execution contexts, and/or privileged and non-privileged access right level execution contexts and generating, in the compilation phase, instructions in machine language having an exclusively secure access right level when the instructions are intended to be executed in the secure access right level execution context, and instructions having a non-privileged access right level when the instructions are intended to be executed in the non-privileged access right level execution context.

Method for executing a software program by a processing unit comprising a compilation phase

A method is provided for monitoring an execution of a selected program code portion stored in a memory address range between a start address and an end address. The method includes starting a timing when a program counter points to the start address of the selected program code portion. Current values of the program counter are compared with a set of target addresses specific to the selected program code portion including the end address of the selected program code portion. The timing is stopped when the program counter points to the end address of the selected program code portion. An error signal is generated in response to the timing duration being outside a nominal duration range specific to the selected program code portion.

Method for monitoring an execution of a program code portion and corresponding system-on-chip

An embodiment system for protecting a memory comprises security software configured to determine, from an exception generated during an unauthorized action attempt in the memory, whether the security software can perform the action.

Protection system and method for a memory

System, method, and circuitry for generating content for a programmable computing device based on user-selected memory regions. Contiguous regions that share memory access attributes are merged, interleaved contiguous regions that share at least one nested attribute are defined into combined regions, and remaining regions are defined as separate independent regions. A memory protection unit (MPU) region size closest to a size of each defined region is identified. If the start address of each region aligns with the address structure of the MPU region size, then those regions are assigned to MPU regions having the MPU region size; otherwise, another MPU size that aligns with the size of the regions is selected and those regions are assigned to MPU regions having that size. Content is generated to configure settings of MPU regions of the programmable computing device for the merged contiguous regions, the combined region, and the independent regions.

Method, system, and circuit for memory protection unit configuration and content generation

In embodiments, a system includes a first and a second processing unit, a memory, and a firewall device. The first processing unit operates in a secure mode and generates memory access requests having a secure level. The second processing unit operates in a non-secure mode and generates memory access requests having a non-secure level. The memory includes a first memory area that can be shared between the first and second processing units. The firewall device includes a first firewall circuit with a first configuration authorizing access to the first memory area in the presence of a secure or non-secure level access request. The firewall circuit includes a second configuration prohibiting access to the first memory area in the presence of a secure level access request and authorizing access to the first memory area only in the presence of a non-secure level access request.

Dynamic management of a memory firewall

A method can be used for verifying an execution of a compiled software program stored in a program memory of a processor and executed by the processor. A write operation includes assigning a destination address in a register of the processor and writing a datum at a location pointed to by the destination address contained in the register. A verification operation includes reassigning the same destination address in the same register, reading the datum contained at the location pointed to by the destination address contained in the register after the reassignment, and comparing the read datum and the written datum.

Method for verifying an execution of a software program

According to one aspect, a method for compiling by a compilation tool a source code into a computer-executable code comprises receiving the source code as input of the compilation tool, translating the source code into an object code comprising machine instructions executable by a processor, then introducing, between machine instructions of the object code, additional instructions selected from illegal instructions and no-operation instructions so as to obtain the executable code, then delivering the executable code as output of the compilation tool.

Growing community of inventors

YVRE L'EVEQUE, France

Michel Jaouen