You could use a custom ATAG to either pass the data block or to pass the address & length of the data. Note that the “A” in ATAG stands for ARM, so this solution is not portable to other architectures. An ATAG is preferable to a command-line bootarg IMO because you do not want the … Read more
(I’m assuming that you’re using ARM based on the mention of U-Boot and the value of LOADADDR.) Can you please help to understand what is the use of this? LOADADDR specifies the address where the kernel image will be located by the linker. (This is true for a few architectures (e.g. Blackfin), but not for … Read more
Even if traditional Bash arrays are not supported, it may still be possible to create array-like variables using the eval command built into the particular shell. The following example script is based on some scripting I did when using BusyBox in an embedded Linux project. BusyBox uses the Almquist shell (also known as A Shell, … Read more
You don’t have root access on Pepper, which limits what you can install (and apt isn’t on the robot anyway). Some possibilities: Include your content in Choregraphe projects – when you install a package, the whole directory structure is installed (more exactly, what’s listed in the .pml); so you can put arbitrary files on your … Read more
Fully automated out-of-tree QEMU example A version of the setup below is also present here: https://github.com/cirosantilli/linux-kernel-module-cheat/tree/753cbe68ff50bea0982e1791c8a2178a999d8377/buildroot_packages/kernel_modules and documented at: https://cirosantilli.com/linux-kernel-module-cheat/kernel-modules-buildroot-package The setup below is full extracted from that repository however, and will work standalone. Source tree: buildroot/: Buildroot 2017.02, ideally as a git submodule kernel_module/: external package with some modules, ideally tracked in the git … Read more
request_mem_region tells the kernel that your driver is going to use this range of I/O addresses, which will prevent other drivers to make any overlapping call to the same region through request_mem_region. This mechanism does not do any kind of mapping, it’s a pure reservation mechanism, which relies on the fact that all kernel device … Read more
A difference between ARM and the x86 is PIO. There are no special instruction on the ARM to access an I/O device. Everything is done through memory mapped I/O. A second difference is the ARM (and RISC in general) has a separate load/store unit(s) that are separate from normal logic. A third difference is that … Read more
What does the “not found” in this case mean ? This usually means that the executable cannot find one or more (shared) libraries to satisfy its external symbols. This usually happens when no libraries are stored in the initramfs, or there is a shared library missing that the executable needs. This can also happen if … Read more
I think you can read this document. Is provides you three small C programs that you can use to understand what happens with the different possible values of /proc/sys/vm/overcommit_memory .
We seem to have ported Das U-Boot successfully. There’s evidence that that is a faulty assumption. Just before calling the kernel, the pointer theKernel is 10008000 and not 10800000. Which version of U-Boot are you using? In both 2012.10 and 2013.04 versions of U-Boot, the variable theKernel is only declared and used by code for … Read more