All complaints fixed except for those that were not possible to fix:
- Used of Mixed case identifier in ESP32 files. These are references to Expressif ROM functions which are outside of the scope of NuttX.
- Remove per-thread errno from the TCB structure (pterrno)
- Remove get_errno() and set_errno() as functions. The macros are still available as stubs and will be needed in the future if we need to access the errno from a different address environment (KERNEL mode).
- Add errno value to the tls_info_s structure definitions
- Move sched/errno to libs/libc/errno. Replace old TCB access to the errno with TLS access to the errno.
Mac OS X was renamed to macOS at some point. Update references to
OSX, OS X, Mac OS X, Mac OSX, and other permutations, to macOS,
in README files and in comments of other files.
lpc2148_spi1.c:142:24: warning: initialization of 'uint32_t (*)(struct spi_dev_s *, uint32_t)' {aka 'unsigned int (*)(struct spi_dev_s *, unsigned int)'} from incompatible pointer type 'uint16_t (*)(struct spi_dev_s *, uint16_t)' {aka 'short unsigned int (*)(struct spi_dev_s *, short unsigned int)'} [-Wincompatible-pointer-types]
142 | .send = spi_send,
| ^~~~~~~~
lpc2148_spi1.c:142:24: note: (near initialization for 'g_spiops.send')
In file included from ieee802154/mac802154_bind.c:49:
ieee802154/mac802154_internal.h: In function 'mac802154_setdevmode':
ieee802154/mac802154_internal.h:788:42: warning: converting a packed 'enum ieee802154_devmode_e' pointer (alignment 1) to a 'const union ieee802154_attr_u' pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
788 | (FAR const union ieee802154_attr_u *)&mode);
| ^~~~~~~~~~~~~~~~~
chip/stm32_hciuart.c: In function 'hciuart_read':
chip/stm32_hciuart.c:2104:30: warning: statement with no effect [-Wunused-value]
2104 | ntotal == (ssize_t)ret;
| ~~~~~~~^~~~~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/bcmf_driver.c: In function 'bcmf_wl_auth_event_handler':
wireless/ieee80211/bcm43xxx/bcmf_driver.c:579:23: warning: taking address of packed member of 'struct bcmf_event_s' may result in an unaligned pointer value [-Waddress-of-packed-member]
579 | type = bcmf_getle32(&event->type);
| ^~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/bcmf_driver.c:580:25: warning: taking address of packed member of 'struct bcmf_event_s' may result in an unaligned pointer value [-Waddress-of-packed-member]
580 | status = bcmf_getle32(&event->status);
| ^~~~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/bcmf_driver.c: In function 'bcmf_wl_scan_event_handler':
wireless/ieee80211/bcm43xxx/bcmf_driver.c:619:25: warning: taking address of packed member of 'struct bcmf_event_s' may result in an unaligned pointer value [-Waddress-of-packed-member]
619 | status = bcmf_getle32(&event->status);
| ^~~~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/bcmf_driver.c:620:35: warning: taking address of packed member of 'struct bcmf_event_s' may result in an unaligned pointer value [-Waddress-of-packed-member]
620 | escan_result_len = bcmf_getle32(&event->len);
| ^~~~~~~~~~~
wireless/ieee80211/bcm43xxx/bcmf_bdc.c: In function 'bcmf_bdc_process_event_frame':
wireless/ieee80211/bcm43xxx/bcmf_bdc.c:166:27: warning: taking address of packed member of 'struct bcmf_event_s' may result in an unaligned pointer value [-Waddress-of-packed-member]
166 | event_id = bcmf_getle32(&event_msg->event.type);
| ^~~~~~~~~~~~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c: In function 'sdio_io_rw_direct':
wireless/ieee80211/bcm43xxx/mmc_sdio.c:157:3: warning: converting a packed 'struct sdio_resp_R5' pointer (alignment 1) to a 'uint32_t' {aka 'unsigned int'} pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
157 | ret = SDIO_RECVR5(dev, SD_ACMD52, (uint32_t *)&resp);
| ^~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:79:28: note: defined here
79 | begin_packed_struct struct sdio_resp_R5
| ^~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c: In function 'sdio_io_rw_extended':
wireless/ieee80211/bcm43xxx/mmc_sdio.c:239:11: warning: converting a packed 'struct sdio_resp_R5' pointer (alignment 1) to a 'uint32_t' {aka 'unsigned int'} pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
239 | ret = SDIO_RECVR5(dev, SD_ACMD53, (uint32_t *)&resp);
| ^~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:79:28: note: defined here
79 | begin_packed_struct struct sdio_resp_R5
| ^~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:244:11: warning: converting a packed 'struct sdio_resp_R5' pointer (alignment 1) to a 'uint32_t' {aka 'unsigned int'} pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
244 | ret = SDIO_RECVR5(dev, SD_ACMD53, (uint32_t *)&resp);
| ^~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:79:28: note: defined here
79 | begin_packed_struct struct sdio_resp_R5
| ^~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:257:7: warning: converting a packed 'struct sdio_resp_R5' pointer (alignment 1) to a 'uint32_t' {aka 'unsigned int'} pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
257 | ret = SDIO_RECVR5(dev, SD_ACMD53, (uint32_t *)&resp);
| ^~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:79:28: note: defined here
79 | begin_packed_struct struct sdio_resp_R5
| ^~~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:265:3: warning: converting a packed 'struct sdio_resp_R5' pointer (alignment 1) to a 'uint32_t' {aka 'unsigned int'} pointer (alignment 4) may result in an unaligned pointer value [-Waddress-of-packed-member]
265 | SDIO_RECVR1(dev, SD_ACMD52ABRT, (uint32_t *)&resp);
| ^~~~~~~~~~~
wireless/ieee80211/bcm43xxx/mmc_sdio.c:79:28: note: defined here
79 | begin_packed_struct struct sdio_resp_R5
| ^~~~~~~~~~~~
chip/stm32_adc.c: In function 'adc_reset':
chip/stm32_adc.c:2860:7: warning: unused variable 'ret' [-Wunused-variable]
2860 | int ret;
| ^~~
chip/stm32_adc.c: In function 'adc_shutdown':
chip/stm32_adc.c:3044:7: warning: unused variable 'ret' [-Wunused-variable]
3044 | int ret;
| ^~~
chip/stm32_i2c.c:722:12: warning: 'stm32_i2c_sem_wait_noncancelable' defined but not used [-Wunused-function]
722 | static int stm32_i2c_sem_wait_noncancelable(FAR struct i2c_master_s *dev)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wireless/gs2200m.c: In function 'gs2200m_read':
wireless/gs2200m.c:727:20: warning: passing argument 1 of 'nxsem_wait' from incompatible pointer type [-Wincompatible-pointer-types]
727 | ret = nxsem_wait(dev);
| ^~~
| |
| struct gs2200m_dev_s *
.config:1207:warning: symbol value '' invalid for TESTING_OSTEST_FPUSIZE
platform/audio/cxd56_audio_analog.c:69:13: warning: inline function 'cxd56_audio_clock_is_enabled' declared but never defined
69 | inline bool cxd56_audio_clock_is_enabled(void);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
platform/audio/cxd56_audio_analog.c:68:13: warning: inline function 'cxd56_audio_clock_disable' declared but never defined
68 | inline void cxd56_audio_clock_disable(void);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
platform/audio/cxd56_audio_analog.c:67:13: warning: inline function 'cxd56_audio_clock_enable' declared but never defined
67 | inline void cxd56_audio_clock_enable(uint32_t clk, uint32_t div);
| ^~~~~~~~~~~~~~~~~~~~~~~~
chip/stm32_adc.c: In function 'adc_reset':
chip/stm32_adc.c:1348:7: warning: unused variable 'ret' [-Wunused-variable]
1348 | int ret;
| ^~~
chip/stm32_adc.c: In function 'adc_shutdown':
chip/stm32_adc.c:1496:7: warning: unused variable 'ret' [-Wunused-variable]
1496 | int ret;
| ^~~
chip/stm32_i2c.c:729:12: warning: 'stm32_i2c_sem_wait_uninterruptble' defined but not used [-Wunused-function]
729 | static int stm32_i2c_sem_wait_uninterruptble(FAR struct i2c_master_s *dev)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wireless/lpwan/sx127x/sx127x.c:147:52: warning: missing terminating ' character
147 | # warning OOK support is not complete, RX+TX doesn't work yet!
| ^
str71_spi.c:435:24: warning: initialization of 'uint32_t (*)(struct spi_dev_s *, uint32_t)' {aka 'unsigned int (*)(struct spi_dev_s *, unsigned int)'} from incompatible pointer type
'uint16_t (*)(struct spi_dev_s *, uint16_t)' {aka 'short unsigned int (*)(struct spi_dev_s *, short unsigned int)'} [-Wincompatible-pointer-types]
435 | .send = spi_send,
| ^~~~~~~~
str71_spi.c:435:24: note: (near initialization for 'g_spiops.send')
chip/pic32mx-lowconsole.c:147:24: warning: 'pic32mx_getreg' defined but not used [-Wunused-function]
static inline uint32_t pic32mx_getreg(uintptr_t uart_base,
^
chip/pic32mx-gpio.c:113:20: warning: 'pic32mx_value' defined but not used [-Wunused-function]
static inline bool pic32mx_value(uint16_t pinset)
^
chip/pic32mz-gpio.c:124:20: warning: 'pic32mz_value' defined but not used [-Wunused-function]
static inline bool pic32mz_value(pinset_t pinset)
^
chip/pic32mx-usbdev.c:3065:1: warning: 'pic32mx_epreserved' defined but not used [-Wunused-function]
pic32mx_epreserved(struct pic32mx_usbdev_s *priv, int epno)
^
mmcsd/mmcsd_spi.c: In function 'mmcsd_mediachanged':
mmcsd/mmcsd_spi.c:1938:7: warning: 'return' with a value, in function returning void
return ret;
^
In file included from partition/fs_partition.c:42:0:
partition/partition.h:66:19: warning: 'read_partition_block' defined but not used [-Wunused-function]
static inline int read_partition_block(FAR struct partition_state_s *state,
^
local/local_netpoll.c: In function 'local_pollsetup':
local/local_netpoll.c:305:1: warning: label 'pollerr' defined but not used [-Wunused-label]
pollerr:
^~~~~~~
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: If3ea8f32b878aa218072130f7c3018f0d3c1aca5
So call 'make EXTRAFLAGS=-Wno-cpp' could suppress the warnings with pre-processor
directive #warning in GCC.
Change-Id: Iaa618238924c9969bf91db22117b39e6d2fc9bb6
Signed-off-by: liuhaitao <liuhaitao@xiaomi.com>
Resolution of Issue 619 will require multiple steps, this part of the first step in that resolution: Every call to nxsem_wait_uninterruptible() must handle the return value from nxsem_wait_uninterruptible properly. This commit is for all I2C drivers under arch/.
There are cases that USE_SERIALDRIVER is defined but USE_EARLYSERIALINIT not defined in some configs. So use ifdef USE_EARLYSERIALINIT to include up_earlyserialinit anyway.
An error was introduced from:
commit f982ee43db
Author: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Tue Feb 18 09:55:04 2020 +0800
drivers/serial: Remove the lowconsole driver
Replace with the syslog console driver which has more capability than lowconsole
And remove syslog_init_e because all initialization is later now and we don't
distinguish the initialition phase anymore after ramlog don't need special
initialize.
Because we can get the same function by CONSOLE_SYSLOG/syslog_console_init.
BTW, it isn't a good choice to use g_ramlogfops as /dev/console since nsh
will read back what it send out which will surprise most people.
it doesn't make sense that iob initialization is in up_initialize
but other memory components initialization is called in nx_start
Change-Id: Id43aeaa995f340c5943f59a0067a483ff3ac34a2
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
To ensure size_t same as toolchain definition in the first place and rename CXX_NEWLONG to ARCH_SIZET_LONG. The change also check whether __SIZE_TYPE__ exist before CONFIG_ARCH_SIZET_LONG so our definition can align with toolchain(gcc/clang) definition automatically.
Call xxx_timer_initialize from clock subsystem to make timer ready for use as soon as possiblei and revert the workaround:
commit 0863e771a9
Author: Gregory Nutt <gnutt@nuttx.org>
Date: Fri Apr 26 07:24:57 2019 -0600
Revert "sched/clock/clock_initialize.c: clock_inittime() needs to be done with CONFIG_SCHED_TICKLESS and clock_initialize should skip clock_inittime() for external RTC case since the RTC isn't ready yet."
This reverts commit 2bc709d4b9.
Commit 2bc709d4b9 was intended to handle the case where up_timer_gettime may not start from zero case. However, this change has the side-effect of breaking every implementation of tickless mode: After this change the tickless timer structures are used before they are initialized in clock_inittime(). Initialization happens later when up_initialize is called() when arm_timer_initialize().
Since the tickless mode timer is very special, one solution might be to
1. Rename xxx_timer_initialize to up_timer_initialize
2 Move up_timer_initialize to include/nuttx/arch.h
3. Call it from clock subsystem instead up_initialize
Basically, this change make timer initialization almost same as rtc initialization(up_rtc_initialize).
For now, however, we just need to revert the change.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
Squashed commit of the following:
Author: Gregory Nutt <gnutt@nuttx.org>
Ran nxstyle against many of the affected files. But this job was too big for today. Many of the network drivers under arch are highly non-compiant and generate many, many faults from nxstyle. Those will have to be visited again another day.
Author: Xiang Xiao <xiaoxiang@xiaomi.com>
This effects all network drivers as well as timing related portions of net/: devif_poll_tcp_timer shouldn't be skipped in the multiple card case. devif_timer will be called multiple time in one period if the multiple card exist, the elapsed time calculated for the first callback is right, but the flowing callback in the same period is wrong(very short) because the global variable g_polltimer is used in the calculation. So let's pass the delay time to devif_timer and remove g_polltimer.
arch/mips/src: Previous commit used CP0 register definitions that were not defined in the cp0.h header file. Probably these were from the Microchip hacked up GCC toolchain but are not generally available. Fix: Add definitions to NuttX cp0.h header file.
mm/iob: Eliminate some warnings about testing the value of an undefined pre-processor variable.
libs/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
syscall/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
wireless/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
Documentation/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
include/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
drivers/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
sched/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
configs: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/xtensa: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/z80: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/x86: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/renesas and arch/risc-v: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/or1k: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/misoc: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/mips: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/avr: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/arm: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
Squashed commit of the following:
configs/: The few configurations that formerly set CONFIG_NFILE_DESCRIPTORS=0 should not default, rather they should set the number of descriptors to 3.
fs/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
tools/: Tools updates for changes to usage of CONFIG_NFILE_DESCRIPTORS.
syscall/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
libs/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
include/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
drivers/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
Documentation/: Remove all references to CONFIG_NFILE_DESCRIPTORS == 0
binfmt/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
arch/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
net/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
sched/: Remove all conditional logic based on CONFIG_NFILE_DESCRIPTORS == 0
sched/Kconfig: CONFIG_NFILE_DESCRIPTORS may no longer to set to a value less than 3
configs/: Remove all settings for CONFIG_NFILE_DESCRIPTORS < 3
sched/init/nx_bringup.c: Fix a naming collision.
sched/init: Rename os_start() to nx_start()
sched/init: Rename os_smp* to nx_smp*
sched/init: Rename os_bringup to nx_bringup
sched/init: rename all internal static functions to begin with nx_ vs os_
Squashed commit of the following:
Trivial, cosmetic
sched/, arch/, and include: Rename task_vforkstart() as nxtask_vforkstart()
sched/, arch/, and include: Rename task_vforkabort() as nxtask_vforkabort()
sched/, arch/, and include: Rename task_vforksetup() as nxtask_vfork_setup()
sched/: Rename notify_cancellation() as nxnotify_cancellation()
sched/: Rename task_recover() to nxtask_recover()
sched/task, sched/pthread/, Documentation/: Rename task_argsetup() and task_terminate() to nxtask_argsetup() and nxtask_terminate(), respectively.
sched/task: Rename task_schedsetup() to nxtask_schedsetup()
sched/ (plus some binfmt/, include/, and arch/): Rename task_start() and task_starthook() to nxtask_start() and nxtask_starthook().
arch/ and sched/: Rename task_exit() and task_exithook() to nxtask_exit() and nxtask_exithook(), respectively.
sched/task: Rename all internal, static, functions to begin with the nx prefix.
When MIPS port is built for microMIPS and then loaded as an application, the __start entry point is entered in microMIPS mode, but the CPU core initialization code there misses to set the config3ISAOnExc bit to 1. Subsequently, exceptions are entered in MIPS32 mode, but the code base was built for microMIPS.
This makes the user interface a little hostile. People thing of an MTU of 1500 bytes, but the corresponding packet is really 1514 bytes (including the 14 byte Ethernet header). A more friendly solution would configure the MTU (as before), but then derive the packet buffer size by adding the MAC header length. Instead, we define the packet buffer size then derive the MTU.
The MTU is not common currency in networking. On the wire, the only real issue is the MSS which is derived from MTU by subtracting the IP header and TCP header sizes (for the case of TCP). Now it is derived for the PKTSIZE by subtracting the IP header, the TCP header, and the MAC header sizes. So we should be all good and without the recurring 14 byte error in MTU's and MSS's.
Squashed commit of the following:
Trivial update to fix some spacing issues.
net/: Rename several macros containing _MTU to _PKTSIZE.
net/: Rename CONFIG_NET_SLIP_MTU to CONFIG_NET_SLIP_PKTSIZE and similarly for CONFIG_NET_TUN_MTU. These are not the MTU which does not include the size of the link layer header. These are the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename CONFIG_NET_6LOWPAN_MTU to CONFIG_NET_6LOWPAN_PKTSIZE and similarly for CONFIG_NET_TUN_MTU. These are not the MTU which does not include the size of the link layer header. These are the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename CONFIG_NET_ETH_MTU to CONFIG_NET_ETH_PKTSIZE. This is not the MTU which does not include the size of the link layer header. This is the full size of the packet buffer memory (minus any GUARD bytes).
net/: Rename the file d_mtu in the network driver structure to d_pktsize. That value saved there is not the MTU. The packetsize is the memory large enough to hold the maximum packet PLUS the size of the link layer header. The MTU does not include the link layer header.
Signal handlers maybe run with interrupts enabled or disabled, depending on how the task the received the signal was blocked. (i.e.: If sem_wait() is called, then we disable interrupts, then block the currently running task). This could be dangerous, because user code would be running with interrupts disabled.
This change forces interrupts to be enabled in up_sigdeliver() before executing the signal handler calling up_irq_enable() explicitly. This is safe because, when we return to normal execution, interrupts will be restored to their previous state when the signal handler returns.
configs/flipnclick-pic32mz: Add an nxlines configuration for use in testing the custom HiletGo Click board.
arch/mips/src/pic32mz: Correct some SPI-related typos. configs/flipnclick-pic32mz: Finishes integration of HiletGo OLED. drivers/lcd: Finish support for HiletGo OLED.
drivers/lcd: Add configuration support for HiletGo OLED. configs/flipnclick-pic32mz: Add board support for HiletGo OLED.
arch/mips/src/pic32mz: Fix some typos in debug instrumentation in pic32mz-gpio.c; fix some types releated to UART5 configuration in pic32mz-serial.c.
configs/flipnclick-pic32mz/nsh: Switch serial console to UART3. There is some problem with the UART4 RX pin documentation or configuration.
configs/flipnclick-pic32mz: Switch the serial console to UART4. Clean up some minor issues the LED options.
configs/flipnclick-pic32mz: Add support for two on-board buttons: T1 and T2.
configs/flipnclick-pic32mz: Adds basic board support for the Mikroe Flip&Click PIC32MZ board. Initial commit is just the configs/pic32mz-starterkit with some name chanages.
arch/mips/src/pic32mz: Commits the basic architecture port for the PIC32MZEF.
arch/mips/src/pic32mz: Begin adding PIC32MZEF files. Initial commit are simply PIC32MZEC files with name changes.
arch/mips/include/pic32mz: Add support for the PIC32MZEF family.
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.
Provide a user defined callback context for irq's, such that when
registering a callback users can provide a pointer that will get
passed back when the isr is called.
