embedded-linux

The start address 0x4806E000 (UART4 base address) is already present in /proc/iomem with the name omap4-uart. How to disable the memory regions already allocated ?. Edit : Even though request_mem_region is successful the console during booting shows this messages. [ 0.758514] Serial: 8250/16550 driver, 3 ports, IRQ sharing enabled [ 0.760040] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 104) is a OMAP UART0 [ 0.760498] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 105) is a OMAP UART1 [ 0.760955] omap_uart.2: ttyO2 at MMIO 0x48020000 (irq = 106) is a OMAP UART2 [ 1.778808] console [ttyO2]

1) Is it possible to access a physical address which is not defined in /proc/iomem? 2) If the physical address range of a device does not appear in /proc/iomem, does it mean that the device has not been utilized/initialized yet? 1) Is it possible to access a physical address which is not defined in /proc/iomem? Yes. Assuming an ARM processor which memory maps all directly-connected periperals, the driver could perform an ioremap() operation to map the physical memory to virtual memory for access. But a properly written driver would first call request_mem_region() to ensure that it can use (and

I've installed crosstool-NG and built GCC on a host+build x86 machine that targets arm-unknown-linux-gnueabi. I've then used arm-unknown-linux-gnueabi-gcc to compile a program that ran well on my ARM board. I'm wanting to now build GCC, targeting ARM to be hosted on ARM. I believe the lingo is build=i486-pc-linux-gnu target=arm-unknown-linux-gnueabi-gcc host=arm-unknown-linux-gnueabi-gcc How do I do this? do I run ./configure for crosstool-NG passing --host=arm-unknown-linux-gnueabi-gcc? or do I change the environment variables for CC/etc? You do this with a .config file. I think samples with

I am working on an user space app for an embedded Linux project using the 2.6.24.3 kernel. My app passes data between two file nodes by creating 2 pthreads that each sleep until a asynchronous IO operation completes at which point it wakes and runs a completion handler. The completion handlers need to keep track of how many transfers are pending and maintain a handful of linked lists that one thread will add to and the other will remove. // sleep here until events arrive or time out expires for(;;) { no_of_events = io_getevents(ctx, 1, num_events, events, &timeout); // Process each aio event

I see that valgrind has an ARM7 target, but I find conflicting information on whether valgrind has support for the ARM9. The ARM9 target I am working with is running linux. Has anyone specifically succeeded in using valgrind on an ARM9 target? If so, any pointers you can offer would be helpful, including "how did you build it?". Thanks -z Valgrind runs on ARM-v7 (architecture name), not ARM7 (chip family name). ARM7 is a name of a fairly old chip family (which uses architecture ARM-v4), as is ARM9 (ARM-v5). Are you sure that your chip is an ARM9 and not a Cortex-A9 (which uses the ARM-v7

I have a DVB receiver ( set-top box ) similar like Dreambox and it has MIPS cpu It has embedded Linux and I can connect to it with telnet Question is how to compile simple " Hello World " application in C ? Where to get toolchain , SDK ? MannyNS You should use Codescape SDK . http://www.linux-mips.org/wiki/Toolchains There you have some prebuilt cross compilers, or the instruction to build GCC as a cross compiler. 来源： https://stackoverflow.com/questions/5291190/how-to-cross-compile-for-mips