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Altera_Forum
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14 years ago

Using custom instruction from uCLinux user app on nios2mmu

Hello, Is it possible to use a custom instruction from an user application running on NIOS2MMU - uCLinux. I'm trying to run the CRC design example on uCLinux. When I try to compile the ...
Altera_Forum's avatar
Altera_Forum
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14 years ago

Since a BSP is not used, you have to write the macros for the custom instructions yourself or use the builtins, which should be defined by the cross compiler.

For example: 

/* Opcode for the byteswap custom instruction provided by Altera.
 * This may change if other custom instructions are present. */
# define ALT_CI_BYTESWAP_N 0x00
# define ALT_CI_BYTESWAP(x) __builtin_custom_ini(ALT_CI_BYTESWAP_N, (x))