How to use assembly function in C++ code

Question: How to use assembly function in C++ code? Answer: When using asm code from C++ code, you have to inform the build tools that these functions are in asm, so that it knows how to call them. When a asm source file is compiled, the function names are given an underscore prefix in the generated assembly. For example, "void foo(int a) {...}" becomes "_foo" in the generated assembly. This is the symbol used to call the function. As C++ supports function overloading, simply adding an underscore would not differentiate between the variances of the same function. So, a suffix is added to the symbol name in assembly when a C++ source file is compiled. For example. "void foo(void)" becomes "_foo__Fv" ("__F" = function, "v" = void), while "void foo(unsigned char *a, int b)" would become "_func__FPUci" in the assembly file, where the "__FPUci" means the Function ("__F") takes a Pointer ("P") to an Unsigned char ("Uc"), and an integer ("i") as it's parameters: "__FPUci". This is true not only when you build the source that contains the function definition, but also when you call the function from your code. Where this causes problems, is if you call "foo(void)" from your C++ source, but the function exists in a asm source file, the generated assembly will call "_foo_Fv", but the linker will not be able to resolve that reference, as compiling the C source file would only produce a symbol "_foo". You can let the Compiler know how to resolve these references using the "extern" qualifier. For example, if you have a function named "asm_func()" in a asm source file, simply add the prototype to your C++ source code (or a header file included by the C++ source) as follows: extern "asm" void asm_func(void); This tells the C++ Compiler that "asm_func ()" is a asm function, and will generate references to this function in the generated assembly. Also please note that, no need to add dot suffix in function definition of " asm_func()”, while using extern qualifier.

Does CCES supports argc and argv in ARM?

Question: Does CCES supports argc and argv in ARM Baremetal project Answer: The GNU ARM Bare-Metal application does not support argc and argv, unlike SHARC and Blackfin. Therefore it was removed from ARM project's generate source file.

Refresh memory window at runtime

Question: Why refreshing memory window is not working during runtime in legacy processors debug but works in latest processors like SC5xx? Answer: The refresh while running is not possible with the legacy processors like 21469 because of the debug architecture of the chip. In order to access memory, we need to use the core to get it and that involves halting the core. For the ADSP-SC58x and newer we can get to memory through a system access which can be done without halting the core.

L1 Block2 PM in Sharc+ core

Question: L1 Block2 PM in Sharc+ core Answer Code segments should not be placed in block2 when cache is enabled. There are two data caches (D-cache) and one instruction cache (I-cache) per SHARC+ core. The data cache is shared with (and uses) block1 which caches all the external memory access requests from the DM bus. Similarly, the other data cache is shared with (and uses) block2 which caches all external memory data access requests from the PM bus. Instruction cache is shared with (and uses) block3. The data cache used by the DM bus is referred to as DM cache and the data cache used by the PM bus is referred to as PM cache. So, by default l1 block2 is for PM data. Therefore, when the cache is enabled in the project, code segment should not be placed in block 2 However, if cache is disabled in project, then placing the code in block 2 works fine and doesn't have impact.

I have a purchase/order details, but lost the license key. What should I do to get my purchased license key?

Please share us more details on product that you have ordered and the part number of product along with a purchased copy / SO# or the DN# etc., or share the purchase order PO#. As the support may limited here in Engineer zone, Please go to our new support portal to create a case. You will then be able to communicate about the case through email. https://support.analog.com