Re: need for packed attribute

Russell King
2006-01-06T18:38:57Z

On Fri, Jan 06, 2006 at 07:15:43PM +0100, Oliver Neukum wrote:
> Hi,
>
> is there any architecture for which packed is required in structures like this:
>
> /* All standard descriptors have these 2 fields at the beginning */
> struct usb_descriptor_header {
> __u8 bLength;
> __u8 bDescriptorType;
> };

sizeof(struct usb_descriptor_header) will be 4 on ARM. If this
concerns you, you need to pack the structure thusly:

struct usb_descriptor_header {
__u8 bLength;
__u8 bDescriptorType;
} __attribute__((packed));

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core