NOTE!!

Since the tools are going to access real hardware registers and may result in unexpected behaviors, it is absolutely not allowed to be used in production environment, but ONLY for TEST and DEBUG.

system-register-tools Build

    0. install MSR-ARM module
    1. make & make install system-register-tools

Introduction

system-register-tools is aiming to access the system registers for arm64 platform. It was designed by SMC (self-modify code) method to read or write date to registers. We use this tool to replace x86 MSR-tools, and depends on MSR-ARM module on use.

In addition, we make the usage of system-register-tools similar to MSR-tools. For engineers familiar with MSR-tools, they can quickly install and use this tool.

HOW-TO

Firstly, the system should make sure have installed the MSR-ARM module.

Next, MSR-ARM module is already installed, install system-register-tools as follows:

    make && make install

To run this program, like follows:

    rdasr -p0 -r MPIDR_EL1

The log here:

For another core, likes: rdasr -p -r MPIDR_EL1

In addition, writing to registers likes:

    wrasr -p0 -r <register name> <write data>

MSR TEST

The script in scripts/ directory is mainly used to start multiple threads to read registers.

In addition, there is a test for all system registers:

    rdasr -t

The log here:

0: OSDTRRX_EL1 : UNDEFINED or unreadable! 1: DBGBVR0_EL1 : 0x0 2: DBGBCR0_EL1 : 0x1e0 3: DBGWVR0_EL1 : 0x0 4: DBGWCR0_EL1 : 0x0 5: DBGBVR1_EL1 : 0x0 6: DBGBCR1_EL1 : 0x1e0 7: DBGWVR1_EL1 : 0x0 8: DBGWCR1_EL1 : 0x0 9: MDCCINT_EL1 : 0x0 10: MDSCR_EL1 : 0x1000 11: DBGBVR2_EL1 : 0x0 … 598: ICC_IGRPEN1_EL3 : UNDEFINED or unreadable! 599: TPIDR_EL3 : UNDEFINED or unreadable! 600: SCXTNUM_EL3 : UNDEFINED or unreadable! 601: CNTPS_TVAL_EL1 : UNDEFINED or unreadable! 602: CNTPS_CTL_EL1 : UNDEFINED or unreadable! 603: CNTPS_CVAL_EL1 : UNDEFINED or unreadable! 604: CNTPS_CVAL_EL1 : UNDEFINED or unreadable!

The test ended and no system exception occurred! Undefined or unreadable registers: 409 Readable registers: 196

Contribution

Read docs/coding_style.txt in docs/
Do NOT use master/dev branch for development directly:

a. Checkout your branch from dev b. Doing something… c. Submit ONLY merge request to dev branch d. After reviewed by maintainers, the patch(es) will be merged into dev e. Only merge dev into master branch when releasing a formal version

Contributors

Rongwei Wang, Cao Zou, Zhuo Song