Contiki sometimes fails to boot correctly and locks up in
random_init()
This problem only manifests itself for specific versions
of the arm-gcc toolchain and then again only for specific
levels of optimisation (-Os vs -O2, depending on the
value of the SMALL make variable)
The lockup is caused when we write an RFCORE XREG before
the RF clock ungating has taken effect, which in turn
only occurs depending on the assembly generated for those
two instructions:
REG(SYS_CTRL_RCGCRFC) = 1;
REG(RFCORE_XREG_FRMCTRL0) = 0x00000008;
This commit makes the RNG wait for the ungating to take
effect before attempting to write the register
The following problems were present in the existing DCO calibration algorithm:
Problem #1. In function msp430_quick_synch_dco(), the "for(i=0; i < 1000; i++) { .. }" loop is optimized away by the compiler, as i is not volatile. Making i volatile would improve the results, but would not be sufficient: see the next point.
Problem #2. According to MSP430F2617 Device Erratasheet, bug BCL12 precludes a naive implementations of "fast" calibration altogether. The bug is present on all MCU revisions up to date.
The description of the bug:
"After switching RSELx bits (located in register BCSCTL1) from a value of >13 to a value of <12 OR from a value of <12 to a value of >13, the resulting clock delivered by the DCO can stop before the new clock frequency is applied. This dead time is approximately 20 us. In some instances, the DCO may completely stop, requiring a power cycle.
Furthermore, if all of the RSELx bits in the BSCTL1 register are set, modifying the DCOCTL register to change the DCOx or the MODx bits could also result in DCO dead time or DCO hang up."
In Contiki code for msp430f2xxx @ 8MHz, the RSEL search currently typically goes from 15 down to 11, thus violating the rules.
Step-by-step RSEL change is proposed as the best possible workaround:
"[..] more reliable method can be implemented by changing the RSEL bits step by step in order to guarantee safe function without any dead time of the DCO."
Problem #3. The old Contiki code started from the highest possible calibration values: RSEL=15, DCOx=7. According to MSP430F2617
datasheet, this means that the DCO frequency is set to 26 MHz. For one, Vcc under 3V is not supported for this frequency, so this means that battery-powered nodes have a big problem. The minimal operating voltages are:
- 1.8V for RSEL <= 13
- 2.2V for RSEL = 14
- 3.0V for RSEL = 15
So the correct way is to always start calibration from RSEL <= 13, unless explicityly pre-calibred values are present.
Problem #4. Timer B should be turned off after the calibration, following the "Principles for Low-Power Applications" in MSP430 user's Guide.
The patch fixes these issues by performing step-by-step calibration and turning off Timer B afterwards. As opposed to MSP430F1xxx calibration, this algorithm does not change the ACLK divider beforehand; attempts to make calibration more precise would lead to looping in some cases, as the calibration step granularity at larger frequencies is quite big.
Additionally, the patch improves DCOSYNCH_CONF_ENABLED behavior, allowing the resynchronization to correct for more than one step.
The CC2538 currently has two addressing options: a hardcoded address set
at compile time or the address stored in primary address section of the
info page. This commit adds the option to choose the secondary location
of the ieee address from the info page, or any memory address.
To use, define `IEEE_ADDR_CONF_USE_SECONDARY_LOCATION` in `project-conf.h`
or similar.
For example:
#define IEEE_ADDR_CONF_USE_SECONDARY_LOCATION 1
Some CFLAGS and LDFLAGS previously only enabled with SMALL=1 have
now been enabled for all builds, regardless of the value of SMALL.
Therefore, from now on, SMALL only chooses between -Os and -O2
As discussed in #503, -Os was broken with one of the toolchains
recommended in the platform's README and for that reason we were
using -O2 by default.
This commit sets the default to -Os and updates the README to no
longer recommend the toolchain in question
lpm.c needs to #include lpm.h in order to get the definition of
lpm_periph_permit_pm1_func_t, which made the replacement macros conflict with
the function definitions for the LPM_CONF_ENABLE == 0 case. This change fixes
this issue by #if-ing out the code in lpm.c in that case. Also, the replacement
macro for lpm_register_peripheral() was missing in that case, which is fixed
here.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
If a project needs to use some libraries at link stage, then the corresponding
linker options (e.g. '-lm') have to be passed after any .o file depending on
these libraries. Hence, LDFLAGS cannot be used to add such options when invoking
$(LD) in Makefile.cc2538, or it should be moved to the correct location.
Instead, this change adds TARGET_LIBFILES to the correct location, like most
other Contiki targets.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
- The default mouse driver is now always named 'contiki.mou'.
- Alternative mouse drivers are present in the disk images.
- Users can select their mouse driver by renaming the files.
The leds API did not work in some cases. E.g. with the following sequence:
leds_off(LEDS_ALL);
leds_toggle(LEDS_GREEN);
leds_off(LEDS_ALL);
the green LED was remaining on after the last call.
This was caused by the toggle feature made synonymous with the invert feature,
although it is unrelated. leds_toggle() is indeed supposed to toggle an LED,
while leds_invert() is supposed to change the active level of an LED. However,
all users of leds_invert() actually meant leds_toggle(), and the invert feature
does not make sense in this module because it is not handy due to successive
calls to leds_invert() changing the intended behavior, and hardware active
levels should be managed in leds_arch_set() (e.g. by XORing the passed value
with a hardware-specific constant before setting the output levels of the pins).
Consequently, this change:
- removes the leds_invert() function,
- makes leds_toggle() behave as expected relatively to leds_off() / leds_on(),
- sanitizes the code in the leds module.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Some SoC data requires huge alignments. E.g., the µDMA channel control table has
to be 1024-byte aligned. This table was simply aligned to 1024 bytes in the C
code, which had the following consequences, wasting a lot of RAM:
- As this table could be placed anywhere in .bss, there could be an alignment
gap of up to 1023 bytes between the preceding data and this table.
- The size of this table was also aligned to 1024 bytes, regardless of
UDMA_CONF_MAX_CHANNEL, making this configuration option supposed to save RAM
just useless.
- .bss was also aligned to at least 1024 bytes, creating a huge alignment gap
between .data and .bss.
Instead of relying on the compiler to force this alignment, and on the linker to
automatically place data, this change places carefully such SoC data in RAM
using the linker script. A dedicated section is created to place such SoC data
requiring huge alignments, and it is put at the beginning of the SRAM in order
to ensure a maximal alignment without any gap. In this way, the alignment of
.bss also remains normal, and the size of this table is not constrained by its
alignment, but only by its contents (i.e. by UDMA_CONF_MAX_CHANNEL).
In the case of the µDMA channel control table, the data is still zeroed by
udma_init() (instead of also being zeroed as part of .bss).
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Normally, the linker does not sort files and sections matched by wildcards, so
they are placed in the order in which they are seen during link. If numerous
objects with different alignments are mixed, or if objects with unusually large
alignments are present, this very likely leads to a lot of space being wasted
because of accumulated alignment gaps.
This commit forces input sections to be sorted by alignment (unless this is
overridden by the linker script), which decreases the number and the size of
alignment gaps, thus saving space.
For a typical Contiki project, this change saves nearly 1 kiB, mainly in .bss.
Note that this behavior is only enabled if the SMALL make variable is set to 1,
because this makes more sense for a size optimization.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
The .nrdata section is volatile, so its initialization must be controlled by the
application, and not be automatically done by the startup code. It should
neither be zeroed like .bss, nor be initialized from data in flash memory like
.data. This was already supposed to be the case, but the output section type of
.nrdata was not set to NOLOAD, causing the generated ELF .nrdata section header
to be of type PROGBITS instead of NOBITS, i.e. load data was generated to be
programmed in RAM, thus producing huge unprogrammable .bin files.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
CFS_WRITE implies O_TRUNC which is implemented on CBM DOS by deleting an
exsisting file. Hoewever this succeeds only if the CBM DOS filetype matches.
We need a working O_TRUNC in order to be able to overwrite the contiki.cfg
configuration file.
Note: Now it has be clarified why overwriting the configuration file started to
fail the CBM PFS (platform file system) can be activated for the recently added
ethconfig program.
The clock adjustments made when waking up from PM1/2 were very inaccurate. If
relying on ContikiMAC's rtimer to sleep, this led to Contiki's software clock
time, seconds and etimers to be 2.5 s slower after each min, i.e. 1 hour slower
after each day, which is a show stopper issue for most real-life applications.
This was caused by a lack of accuracy in several pieces of code during sleep
entry and wake-up:
- It was difficult to synchronize the calls to RTIMER_NOW() before and after
sleep with the deactivation and activation of the SysTick peripheral caused
by PM1/2. This caused an inaccuracy in the corrective number of ticks passed
to clock_adjust().
- The value passed to clock_adjust() was truncated from an rtimer_clock_t
value, but the accumulated error caused by these truncated bits was ignored.
- The SysTick peripheral had to be stopped during the call to clock_adjust().
Rather than creating even more complicated clock adjustment mechanisms that
would probably still have mixed results as to accuracy, this change simply uses
the Sleep Timer counter as a base value for Contiki's clock and seconds
counters. The tick from the Systick peripheral is still used as the interrupt
source to update Contiki's clocks and timers. When running, the SysTick
peripheral and the Sleep Timer are synchronized, so combining both is not an
issue, and this allows not to alter the rtimer interrupt mechanism using the
Sleep Timer. The purpose of the Sleep Timer is to be an RTC, so it is the
perfect fit for the clock module, all the more it can not be disturbed by PM1/2.
If the 32-kHz XOSC is used, the Sleep Timer is also very accurate. If the
32-kHZ RCOSC is used, it is calibrated from the 32-MHz XOSC, so it is also
accurate, and the 32753-Hz vs. 32768-Hz systematic error in that case is
negligible, all the more one would use the 32-kHz XOSC for better accuracy.
Besides fixing this time drift issue, this change has several benefits:
- clock_time(), clock_seconds() and RTIMER_NOW() start synchronized, and they
change at the same source pace.
- If clock_set_seconds() is called, then clock_seconds() indicates one more
second almost exactly one second later, then exactly each second. Before this
change, clock_seconds() was not synchronized with clock_set_seconds(), so the
value returned by the former could be incremented immediately after the call
to the latter in some cases.
- The code tied to the clock module is simpler and more robust.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Whole elapsed seconds are added to secs first, so only the remaining subsecond
ticks should then be subtracted from second_countdown in order to decide whether
secs should be incremented again.
Otherwise, secs is not correctly updated in some cases, typically if the bit 7
of ticks is 1. E.g., with ticks = 128 (i.e. exactly 1 s elapsed) and
second_countdown = 128, secs was first incremented as expected, then 128 was
subtracted from second_countdown, giving 0 and triggering an unwanted second
increment of secs. Or with ticks = 129 (i.e. 1 s + 1 tick) and
second_countdown = 1, secs was first incremented as expected, then 129 was
subtracted from second_countdown, giving 128 and missing a second increment of
secs that should have occurred because second_countdown wrapped around.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
During PM1+, the hardware timer used to implement the Contiki clock is frozen,
so clock_adjust() needs to be called when exiting those modes in order to
compensate for the clock ticks missed while the timer was frozen. Doing so
changes the Contiki clock time, so etimer_request_poll() needs to be called in
order to inform the etimer library that an etimer might have expired.
Note that waiting for the next clock ISR to call etimer_request_poll() is
unreliable because the system might go back to sleep beforehand.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
When returning from PM1/2, the sleep timer value (used by RTIMER_NOW()) is not
up-to-date until a positive edge on the 32-kHz clock has been detected after the
system clock restarted. To ensure an updated value is read, wait for a positive
transition on the 32-kHz clock by polling the SYS_CTRL_CLOCK_STA.SYNC_32K bit,
before reading the sleep timer value.
Because of this RTIMER_NOW() fixup, lpm_exit() has to be called at the very
beginning of ISRs waking up the SoC. This also ensures that all clocks and
timers are enabled at the correct frequency and updated before using them
following wake-up.
Without this fix, etimers could sometimes (randomly, depending on timings)
become ultra slow (observed from 10x to 40x slower than normal) if the system
exited PM1/2 very often. This issue occurred more often with PM1.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
As recommended by the CC2538 User's Guide, set SYS_CTRL_CLOCK_CTRL.OSC_PD to 0
before asserting WFI, and set it to 1 after the system clock is sourced from the
32-MHz XOSC following wake-up. This allows to automatically start both
oscillators upon wake-up in order to partially hide the 32-MHz XOSC startup time
by the 16-MHz RCOSC startup time.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
As a matter of precaution, always make sure that pending system clock
transitions are complete before requesting a new change of the system clock
source.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
In one of the abort cases in lpm_enter(), the energest context has previously
been set to LPM, so the abort code needs to set it back to CPU.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Create a dedicated header file with all the definitions for the flash lock bit
page and customer configuration area. This avoids duplicating those definitions
in the startup-gcc.c files of all CC2538-based platforms, and this also allows
to easily manipulate the CCA from outside startup-gcc.c (e.g. for on-the-air
firmware update).
The definitions are now complete contrary to what was in startup-gcc.c:
- Definitions have been added to select the bootloader backdoor pin and active
level if enabled.
- Definitions have been added to access the page and debug lock bits. The debug
lock bit can be used to prevent someone from reading back a programmed
firmware through JTAG if the firmware binary image has to be confidential,
which should be combined with a disabled bootloader backdoor.
- The application entry point is now tied to the beginning of the .text section
instead of to the beginning of the flash. This allows projects using custom
linker scripts to place the application entry point anywhere in the flash,
which can be useful e.g. for on-the-air firmware update.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
