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Diffstat (limited to 'Documentation/ioctl/ioctl-decoding.txt')
| -rw-r--r-- | Documentation/ioctl/ioctl-decoding.txt | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/Documentation/ioctl/ioctl-decoding.txt b/Documentation/ioctl/ioctl-decoding.txt deleted file mode 100644 index e35efb0cec2e..000000000000 --- a/Documentation/ioctl/ioctl-decoding.txt +++ /dev/null @@ -1,24 +0,0 @@ -To decode a hex IOCTL code: - -Most architectures use this generic format, but check -include/ARCH/ioctl.h for specifics, e.g. powerpc -uses 3 bits to encode read/write and 13 bits for size. - - bits meaning - 31-30 00 - no parameters: uses _IO macro - 10 - read: _IOR - 01 - write: _IOW - 11 - read/write: _IOWR - - 29-16 size of arguments - - 15-8 ascii character supposedly - unique to each driver - - 7-0 function # - - -So for example 0x82187201 is a read with arg length of 0x218, -character 'r' function 1. Grepping the source reveals this is: - -#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2]) |