Using FPU with uCLinux

Hello folks,

i'am just trying to use the floating-point-unit within my uCLinux dist.

I have added the corresponding custom instruction to the cpu within my sopc-builder system.

After that i configured the kernel to use the fpu (CONFIG_NIOS2_FPU_SUPPORT).

But when i issue cat /proc/cpuinfo it comes up with the following informations saying that there is no fpu present:

CPU: Nios II/fast

MMU: present

FPU: none

Clocking: 107.05 MHz

BogoMips: 52.73

Calibration: 26368000 loops

HW:

MUL: yes

MULX: no

DIV: yes

Icache: 32kB, line length: 32

Dcache: 16kB, line length: 32

TLB: 16 ways, 256 entries

Any ideas?

Altera_Forum
Honored Contributor
14 years ago
You might be right, that adding own programms to the uCLinux dist is the "correct way". But i want the uCLinux-dist to boot from an EPCS, then mount another device e.g. cfi-flash wich contains my user-space programms and some kernel-moduls and start everything using some scripts. --> Isn't it a good idea?
Altera_Forum
Honored Contributor
14 years ago
I do suppose this is possible and in fact might be a good idea.

But I would first do a "hello world" example in the "normally correct" way to learn how the make file and the linker script need to be constructed. This done, you can decide how to proceed to place the file on an external media instead of inside the distribution.

When doing my own application I in fact used a symlink for the "correct" directory under "Vendors" so that "physically" my files were outside of the distribution make tree, anyway.

In fact I would only slightly modify the "correct" makefile so that the executable after being linked is not included in (moved to ?, symlinked to ? I don't remember... ) the directory that is zipped to be the root file system that is included in or comes with the Kernel Image.

-Michael

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