{"id":118,"date":"2018-02-05T15:34:22","date_gmt":"2018-02-05T23:34:22","guid":{"rendered":"https:\/\/sysprogs.com\/tutorials\/?p=118"},"modified":"2018-02-06T18:53:00","modified_gmt":"2018-02-07T02:53:00","slug":"debugging-raspberry-pi-kernel-with-visualkernel","status":"publish","type":"post","link":"https:\/\/sysprogs.com\/VisualKernel\/tutorials\/raspberry\/debugkernel\/","title":{"rendered":"Debugging Raspberry PI Kernel with VisualKernel"},"content":{"rendered":"

This tutorial shows how to debug a the Linux Kernel on Raspberry PI over JTAG using Visual Studio. Before you begin, follow the\u00a0basic Raspberry PI Kernel Module tutorial<\/a>\u00a0to ensure that your debugging setup works.<\/p>\n

    \n
  1. Start Visual Studio. Select File->New->Project->VisualKernel->Custom Linux Kernel Wizard:\"\"<\/li>\n
  2. Specify the same target settings you used in the\u00a0Kernel Module tutorial<\/a>:\"\"<\/li>\n
  3. Select “Automatically download sources” and click “Next”:\"\"<\/li>\n
  4. VisualKernel will automatically download the Raspberry Pi cross-toolchain and the kernel sources\u00a0to the machine selected for building:\"\"<\/li>\n
  5. On the next page of the wizard select\u00a0the method to access the source code on the build machine. For most scenarios we recommend using direct SSH access. If you want to keep a local copy of the sources,\u00a0select “Copy sources locally and upload modified files” instead:\"\"<\/li>\n
  6. Enter the same debug settings that you used when\u00a0testing the kernel module. Use the “test” button to validate them:
    \n\"\"<\/li>\n
  7. Press Finish to generate the project. VisualKernel will create an advanced kernel project and will begin\u00a0querying its structure from KBuild:\"\"<\/li>\n
  8. Once the structure is queried, press Ctrl-Shift-B to build the kernel.\u00a0The build may stop on an internal compiler error in\u00a0dwarf2out_frame_debug_adjust_cfa()<\/strong>:\"\"<\/li>\n
  9. To work around this, open both failing files and insert the following code at the beginning of them:\n
    #pragma GCC optimize(\"-g0\")<\/pre>\n
    \"\"<\/li>\n
  10. Then build the\u00a0project again. The build will now succeed and VisualKernel will\u00a0remind you to\u00a0install the kernel on\u00a0Raspberry Pi:\"\"<\/li>\n
  11. Open VisualKernel Project Properties on the Kernel build settings page and click “Install embedded kernel”:\"\"<\/li>\n
  12. VisualKernel will automatically export the built kernel, transfer it to Raspberry Pi and install it there, including the related modules:\"\"<\/li>\n
  13. Once the installation is complete, restart\u00a0Raspberry Pi and ensure the new kernel starts:\"\"<\/li>\n
  14. Press F5 to start debugging the kernel. VisualKernel will begin analyzing the kernel image and once it is done, the debugging session will automatically start:\"\"<\/li>\n
  15. Set a breakpoint in the sys_open()<\/strong> function via the Breakpoints window:\"\"<\/li>\n
  16. The breakpoint will soon hit:\"\"If it doesn’t get triggered, try\u00a0reading any file on your Raspberry Pi using the ‘cat’ command.<\/li>\n
  17. Press F11 until you step into do_sys_open(). Hover the mouse around various variables to see their values:\"\"<\/li>\n
  18. If stepping through the kernel is too slow due to multiple printk() messages, you can disable printk() hooking via VisualKernel Project Properties:\"\"<\/li>\n
  19. You can edit the kernel configuration by right-clicking on the kernel project and selecting “Configure Kernel Project”:\"\"<\/li>\n
  20. This will launch the xconfig\u00a0tool, letting you configure various kernel parameters directly from your Windows machine:\"\"<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
    This tutorial shows how to debug a the Linux Kernel on Raspberry PI over JTAG using Visual Studio. Before you<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[34,37],"_links":{"self":[{"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/posts\/118"}],"collection":[{"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/comments?post=118"}],"version-history":[{"count":3,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/posts\/118\/revisions"}],"predecessor-version":[{"id":241,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/posts\/118\/revisions\/241"}],"wp:attachment":[{"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/media?parent=118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/categories?post=118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sysprogs.com\/tutorials\/wp-json\/wp\/v2\/tags?post=118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}