uClinux usb host support

Development Boards MicroMod
1

Hello,

I have an LPC2478STK purchased from Olimex. This comes together with an uClinux distribution, cross compiler and bootloader.

Now I want to use the usb controller to use an Bluetooth dongle on my board. The goal of my project is to create a Bluetooth connection from the board.

Within the kernel (2.6.24.2) of the distribution I have enable the USB-support (in device drivers) and the I have enabled then Support for Host-side USB. That is required to use the Bluetooth dongle of the pc.

However when I exit the menuconfig of the kernel and issue a make in the uClinux distribution I get the following error:

##########################################################################

:1365:2: warning: #warning syscall epoll_pwait not implemented

CHK include/linux/compile.h

LD drivers/usb/built-in.o

LD drivers/built-in.o

LD vmlinux.o

MODPOST vmlinux.o

GEN .version

CHK include/linux/compile.h

UPD include/linux/compile.h

CC init/version.o

LD init/built-in.o

LD vmlinux

drivers/built-in.o: In function `dma_map_sg’:

include/asm/dma-mapping.h:281: undefined reference to `dma_cache_maint’

drivers/built-in.o: In function `dma_map_single’:

include/asm/dma-mapping.h:168: undefined reference to `dma_cache_maint’

include/asm/dma-mapping.h:168: undefined reference to `dma_cache_maint’

make[1]: *** [vmlinux] Error 1

make[1]: Leaving directory `/home/user/lpc-2478-uclinux/uClinux-dist-lpc_2478_stk/linux-2.6.24.2-lpc2478-patched’

make: *** [linux] Error 1

#######################################################################

That is the only thing I have changed instead of the default configuration.

Does anybody have any idea how to solve this ??

Thanks in advance,

Erwin

2

I have the same problem. I found dma_cache_maint defined here:

linux-2.6.24.2-lpc2478-patched/arch/arm/mm/consistent.c:483:void dma_cache_maint(const void *start, size_t size, int direction)

linux-2.6.x/arch/arm/mm/consistent.c:483:void dma_cache_maint(const void *start, size_t size, int direction)

I included the MMU in the kernel menuconfig options and it compiled, but it would hang when trying to startup uClinux. I did a make clean and removed the MMU option from my config and it would still hang. I had to unpack the src code into another folder and rebuild the image from scratch (without MMU and USB host) to get uClinux to boot again.

3

That uClinux not boot looks logical because our processor (lpc 2478) has no mmu.

I’ve looked deeper into the problem.

within dmamapping.h there is an prototype:

extern void dma_cache_maint(const void *kaddr, size_t size, int rw);

that is the one being called.

Within the same file there is also an include to <mm.h> and when you look in the folder:

uClinux-dist-lpc_2478_stk/linux-2.6.24.2-lpc2478-patched/arch/arm/mm

there is a makefile which has the following content:

obj-$(CONFIG_MMU) += fault-armv.o flush.o ioremap.o mmap.o \

pgd.o mmu.o consistent.o

ifneq ($(CONFIG_MMU),y)

obj-y += nommu.o consistent-nommu.o

endif

Within this folder the nommu.o and the consistent-nommu.o is being linked and the function that dmamapping.h is looking is within consistent.o which is not being linked.

However within the file consistent-nommu.c there is a function called:

void consistent_sync(const void *start, size_t size, int direction)

It looks like this function is the replacement of

void dma_cache_maint(const void *start, size_t size, int direction) within consistent.c

The solution might be to replace the dma_cache_maint to consistent_sync and hopes it works. I will try it out and post if I have news.

Kind regards,

Erwin

4

Hello,

I’ve done the following:

Within the file /include/asm/dma-mapping.h:

On rule 20:

//extern void dma_cache_maint(const void *kaddr, size_t size, int rw);

extern void consistent_sync(const void *start, size_t size, int direction);

Further on within the same file, everywhere dma_cache_maint is called, I call the method consistent_sync.

For example:

consistent_sync(cpu_addr, size, dir);

//dma_cache_maint(cpu_addr, size, dir);

Afterwards I have run a “make” command in de uClinux distribution and everything builds. Afterwards booted the board and no problems.

Then I’ve configured the kernel to support my usb bluetooth dongle.

The following configuration:

In Device Drivers->USB support:

  • Support for Host-side USB

  • USB verbose debug messages

  • USB device filesystem

  • USB device class-devices (DEPRECATED)

  • ISP116X HCD support

ISP1362 HCD support

  • SL811HS HCD support

  • R8A66597 HCD support

  • USB Mass Storage support

In Networking →

  • Bluetooth subsystem support —>

  • L2CAP protocol support

  • SCO links support

  • RFCOMM protocol support

  • RFCOMM TTY support

  • BNEP protocol support

  • Multicast filter support

  • Protocol filter support

  • HIDP protocol support

Bluetooth device drivers —>

  • HCI USB driver

  • SCO (voice) support

  • HCI UART driver

  • UART (H4) protocol support

  • BCSP protocol support

HCILL protocol support

  • HCI BCM203x USB driver

  • HCI BPA10x USB driver

  • HCI BlueFRITZ! USB driver

  • HCI VHCI (Virtual HCI device) driver

If afterwards I try to open the device, I get the message that there is no such device.

It looks like the usb dongle is not connected.

Within the boot messages of the board I can see a lot of drivers loaded however I can’t find anywhere that a usb device has been connected. How can I verify if a device has been connected and what do I have to change to make the device work.

I hope anyone can help.

Regards

Erwin