Pullreq FAT improvements
* NuttX: Add CONFIG_FAT_LFN_ALIAS_HASH to speed up creating long filenames.
Long filenames on FAT filesystems have associated 8.3 character alias
short filenames. The traditional form of these is FILENA~1.EXT with
a running count of the number of similar names. However creating this
unique count can take several seconds if there are many similarly named
files in the directory. Enabling FAT_LFN_ALIAS_HASH uses an alternative
format of FI0123~1.TXT where the four digits are a hash of the original
filename. This method is similar to what is used by Windows 2000 and
later.
* NuttX: Add CONFIG_FAT_LFN_ALIAS_TRAILCHARS alternative format for 8.3 filenames.
Traditional format for long filename 8.3 aliases takes first 6
characters of long filename. If this option is set to N > 0,
NuttX will instead take first 6-N and last N characters to form
the short name. This is useful for filenames like "datafile12.txt"
where the first characters would always remain the same.
* NuttX: FAT32: Fix file date corruption in fat_truncate().
* NuttX: if SD card wait seems to be a long one, give time for other threads to run.
Approved-by: GregoryN <gnutt@nuttx.org>
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
This commit backs out most of commit b4747286b1. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point.
In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable.
In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable.
sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post().
sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy().
libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
and this one https://www.sdcard.org/downloads/pls/simplified_specs/part1_410.pdf) shows that ACMD23
must be preceeded with CMD55 command as any other ACMD commands.
Also, after the block reading wait loop must be inserted before writing the next block of data to
the sd card
From Dmitry Nikolaev via Jussi Kivilinna
