From 865c5dcc2a0d27ded9135acf7fd1066f55acf5ca Mon Sep 17 00:00:00 2001 From: oharboe Date: Fri, 19 Dec 2008 14:48:00 +0000 Subject: Dick Hollenbeck better comments git-svn-id: svn://svn.berlios.de/openocd/trunk@1261 b42882b7-edfa-0310-969c-e2dbd0fdcd60 --- src/helper/types.h | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'src/helper/types.h') diff --git a/src/helper/types.h b/src/helper/types.h index e4b37a42..82368a92 100644 --- a/src/helper/types.h +++ b/src/helper/types.h @@ -46,18 +46,22 @@ typedef unsigned long long u64; typedef struct jtag_tap_s jtag_tap_t; -/* DANGER!!!! here be dragons! - * +/* DANGER!!!! here be dragons! + * * Leave these fn's as byte accesses because it is safe * across architectures. Clever usage of 32 bit access * will create problems on some hosts. - * - * Note that the pointer in memory might be unaligned. - * - * On some CPU's, i.e. ARM7, the 2 lsb are ignored for 32 - * bit access, on others it will cause an exception and - * on e.g. x86, it works the same as if aligned. - * + * + * Note that the "buf" pointer in memory is probably unaligned. + * + * Were these functions to be re-written to take a 32 bit wide or 16 bit wide + * memory access shortcut, then on some CPU's, i.e. ARM7, the 2 lsbytes of the address are + * ignored for 32 bit access, whereas on other CPU's a 32 bit wide unaligned memory access + * will cause an exception, and lastly on x86, an unaligned "greater than bytewide" + * memory access works as if aligned. So what follows below will work for all + * platforms and gives the compiler leeway to do its own platform specific optimizations. + * + * Again, note that the "buf" pointer in memory is probably unaligned. */ -- cgit v1.2.3