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author | Gregory Nutt <gnutt@nuttx.org> | 2015-04-13 07:39:56 -0600 |
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committer | Gregory Nutt <gnutt@nuttx.org> | 2015-04-13 07:39:56 -0600 |
commit | dac105b64ee0c2544d14cbb7733c6861fb53a314 (patch) | |
tree | 837d89df3c8d2a996c1d9e442ce56e6563f7b25f /nuttx | |
parent | ddd9938f87309a69b1aeffc3b2f5455aff27fb7a (diff) | |
download | px4-nuttx-dac105b64ee0c2544d14cbb7733c6861fb53a314.tar.gz px4-nuttx-dac105b64ee0c2544d14cbb7733c6861fb53a314.tar.bz2 px4-nuttx-dac105b64ee0c2544d14cbb7733c6861fb53a314.zip |
Update some comments
Diffstat (limited to 'nuttx')
-rw-r--r-- | nuttx/fs/fat/fs_fat32util.c | 26 | ||||
-rw-r--r-- | nuttx/libc/Kconfig | 7 |
2 files changed, 20 insertions, 13 deletions
diff --git a/nuttx/fs/fat/fs_fat32util.c b/nuttx/fs/fat/fs_fat32util.c index a0f6b0ebf..ac2f53365 100644 --- a/nuttx/fs/fat/fs_fat32util.c +++ b/nuttx/fs/fat/fs_fat32util.c @@ -296,7 +296,10 @@ static int fat_checkbootrecord(struct fat_mountpt_s *fs) uint16_t fat_getuint16(uint8_t *ptr) { - /* Byte-by-byte transfer is still necessary if the address is un-aligned */ + /* NOTE that (1) this operation is independent of endian-ness and that (2) + * byte-by-byte transfer is necessary in any case because the address may be + * unaligned. + */ return ((uint16_t)ptr[1] << 8) | ptr[0]; } @@ -307,7 +310,10 @@ uint16_t fat_getuint16(uint8_t *ptr) uint32_t fat_getuint32(uint8_t *ptr) { - /* Byte-by-byte transfer is still necessary if the address is un-aligned */ + /* NOTE that (1) this operation is independent of endian-ness and that (2) + * byte-by-byte transfer is necessary in any case because the address may be + * unaligned. + */ return ((uint32_t)fat_getuint16(&ptr[2]) << 16) | fat_getuint16(&ptr[0]); } @@ -321,13 +327,17 @@ void fat_putuint16(uint8_t *ptr, uint16_t value16) uint8_t *val = (uint8_t*)&value16; #ifdef CONFIG_ENDIAN_BIG - /* The bytes always have to be swapped if the target is big-endian */ + /* If the target is big-endian then the bytes always have to be swapped so + * that the representation is litle endian in the file system. + */ ptr[0] = val[1]; ptr[1] = val[0]; #else - /* Byte-by-byte transfer is still necessary if the address is un-aligned */ + /* Byte-by-byte transfer is still necessary because the address may be + * un-aligned. + */ ptr[0] = val[0]; ptr[1] = val[1]; @@ -343,13 +353,17 @@ void fat_putuint32(uint8_t *ptr, uint32_t value32) uint16_t *val = (uint16_t*)&value32; #ifdef CONFIG_ENDIAN_BIG - /* The bytes always have to be swapped if the target is big-endian */ + /* If the target is big-endian then the bytes always have to be swapped so + * that the representation is litle endian in the file system. + */ fat_putuint16(&ptr[0], val[1]); fat_putuint16(&ptr[2], val[0]); #else - /* Byte-by-byte transfer is still necessary if the address is un-aligned */ + /* Byte-by-byte transfer is still necessary because the address may be + * un-aligned. + */ fat_putuint16(&ptr[0], val[0]); fat_putuint16(&ptr[2], val[1]); diff --git a/nuttx/libc/Kconfig b/nuttx/libc/Kconfig index 0a7a732ca..e4da4d61d 100644 --- a/nuttx/libc/Kconfig +++ b/nuttx/libc/Kconfig @@ -274,13 +274,6 @@ config LIBC_LOCALTIME timezone file is required for any another time zone and the environment variable TZ must be set to the name of that file. - There is an issue with mktime being called very early in initialization - by the OS before there are any file systems available. - - And finally, the times presented by the NSH date command are wrong when - this logic is enabled. I assume that this is due to some inconsistency - between the NuttX timing logic and the localtime timing logic. - if LIBC_LOCALTIME config LIBC_TZ_MAX_TIMES |