From a2b22dddc7bb6110ac3b5ed1a60aa9279836fadb Mon Sep 17 00:00:00 2001 From: Peter Senna Tschudin Date: Tue, 10 Jul 2018 16:01:45 +0200 Subject: [PATCH] tools: usb: ffs-test: Fix build on big endian systems MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The tools/usb/ffs-test.c file defines cpu_to_le16/32 by using the C library htole16/32 function calls. However, cpu_to_le16/32 are used when initializing structures, i.e in a context where a function call is not allowed. It works fine on little endian systems because htole16/32 are defined by the C library as no-ops. But on big-endian systems, they are actually doing something, which might involve calling a function, causing build failures, such as: ffs-test.c:48:25: error: initializer element is not constant #define cpu_to_le32(x) htole32(x) ^~~~~~~ ffs-test.c:128:12: note: in expansion of macro ‘cpu_to_le32’ .magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2), ^~~~~~~~~~~ To solve this, we code cpu_to_le16/32 in a way that allows them to be used when initializing structures. This fix was imported from meta-openembedded/android-tools/fix-big-endian-build.patch written by Thomas Petazzoni . CC: Thomas Petazzoni Signed-off-by: Peter Senna Tschudin Signed-off-by: Felipe Balbi --- tools/usb/ffs-test.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/tools/usb/ffs-test.c b/tools/usb/ffs-test.c index 95dd14648ba5..0f395dfb7774 100644 --- a/tools/usb/ffs-test.c +++ b/tools/usb/ffs-test.c @@ -44,12 +44,25 @@ /******************** Little Endian Handling ********************************/ -#define cpu_to_le16(x) htole16(x) -#define cpu_to_le32(x) htole32(x) +/* + * cpu_to_le16/32 are used when initializing structures, a context where a + * function call is not allowed. To solve this, we code cpu_to_le16/32 in a way + * that allows them to be used when initializing structures. + */ + +#if __BYTE_ORDER == __LITTLE_ENDIAN +#define cpu_to_le16(x) (x) +#define cpu_to_le32(x) (x) +#else +#define cpu_to_le16(x) ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)) +#define cpu_to_le32(x) \ + ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \ + (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24)) +#endif + #define le32_to_cpu(x) le32toh(x) #define le16_to_cpu(x) le16toh(x) - /******************** Messages and Errors ***********************************/ static const char argv0[] = "ffs-test";