Re: [RFC PATCH v2 02/12] of: Allow scripts/dtc/libfdt to be used from kernel code
From: David Gibson <hidden>
Date: 2011-03-05 08:30:05
Also in:
linux-mips, lkml
On Fri, Mar 04, 2011 at 11:42:14AM -0800, David Daney wrote:
Signed-off-by: David Daney <redacted>
[snip]
quoted hunk ↗ jump to hunk
--- /dev/null +++ b/lib/libfdt/libfdt_env.h@@ -0,0 +1,21 @@ +#ifndef _LIBFDT_ENV_H +#define _LIBFDT_ENV_H + +#include <linux/string.h> + +#define _B(n) ((unsigned long long)((uint8_t *)&x)[n]) +static inline uint32_t fdt32_to_cpu(uint32_t x) +{ + return (_B(0) << 24) | (_B(1) << 16) | (_B(2) << 8) | _B(3); +} +#define cpu_to_fdt32(x) fdt32_to_cpu(x) + +static inline uint64_t fdt64_to_cpu(uint64_t x) +{ + return (_B(0) << 56) | (_B(1) << 48) | (_B(2) << 40) | (_B(3) << 32) + | (_B(4) << 24) | (_B(5) << 16) | (_B(6) << 8) | _B(7); +} +#define cpu_to_fdt64(x) fdt64_to_cpu(x) +#undef _B
Ah, yuck. I only used those nasty macros in the userspace version of
libfdt_env.h because bytesex.h is such a portability nightmare. The
kernel already has cpu_to_be{32,64}(), and the fdt byteswapping
functions should just be aliased to them.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson