currently esp32 protected mode requires a patched bootloader.
it's a bit cumbersome to build the bootloader for that purpose.
this commit attempts to remove the need of the patched bootloader
by applying the changes by ourselves using esp hal.
64-by-32-bit divisions are prominent in the NuttX, even on 32-bit
machines. Luckily, many of them use a constant divisor that allows
for a much faster multiplication by the divisor's reciprocal.
The compiler already performs this optimization when compiling a 32-by-32
division with a constant divisor. Unfortunately, on 32-bit machines, gcc
does not optimize 64-by-32 divisions in that case, except for constant
divisors that happen to be a power of 2.
Let's avoid the slow path whenever the divisor is constant by manually
computing the reciprocal ourselves and performing the multiplication
inline. In most cases, this improves performance of 64-by-32 divisions
by about two orders of magnitude compared to the __div64_32() fallback,
especially on architectures lacking a native div instruction.
Signed-off-by: ligd <liguiding1@xiaomi.com>
CID 1266677: (#2 of 2): Use 32-bit time_t (Y2K38_SAFETY)
1. declaration_with_small_time_t: Declare use of time_t, which is defined as 32 bits wide on this platform, while the minimum safe width is 64.
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
Signed-off-by: ligd <liguiding1@xiaomi.com>
Using the ts/tick conversion functions provided in clock.h
Do this caused we want speed up the time calculation, so change:
clock_time2ticks, clock_ticks2time, clock_timespec_add,
clock_timespec_compare, clock_timespec_subtract... to MACRO
Signed-off-by: ligd <liguiding1@xiaomi.com>
enable debug messages for PCI configuration in qemu-intel64
so we know exactly what happen during execution
Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
Enforcing the default 48-bit VA for everyone also implies a 4 page table
translation system. However, if less than 40 bits are needed, a full
translation table level can be dropped, making the translations faster.
Thus, make this into a configurable option, instead of enforcing the same
address widht for everyone.
Attempt to service all interrupts pending in the PLIC's claim register. Ideally, this is more efficient than switching context for each interrupt received.
Provides two implementations:
- CSR_CYCLE: Cores which implement hardware performance monitoring.
- CSR_TIME: Uses the machine time registers.
Using the up_perf_xx bindings directory is more efficient than performing a nanosecond conversion on every gettime event.
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
1 Only the idle task can have the flag TCB_FLAG_CPU_LOCKED.
According to the code logic, btcb cannot be an idle task, so this check can be removed.
2 Optimized the preemption logic check and removed the call to nxsched_add_prioritized.
3 Speed up the scheduling time while avoiding the potential for
tasks to be moved multiple times between g_assignedtasks and g_readytorun.
Configuring NuttX and compile:
$ ./tools/configure.sh -l qemu-armv8a:nsh_smp
$ make
Running with qemu
$ qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic \
-machine virt,virtualization=on,gic-version=3 \
-net none -chardev stdio,id=con,mux=on -serial chardev:con \
-mon chardev=con,mode=readline -kernel ./nuttx
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
There is a tiny possibility that when a process is started a trap is
taken which causes a context switch. This moves the kernel stack
unexpectedly and the task start logic no longer works.
Fix this by recording the initial context location, and use that to
trampoline into the user process with interrupts disabled. This ensures
the context stays intact AND the kernel stack is fully unwound before
the user process starts.
This patch unifies the extended context save/restore for RISC-V,
allowing the customized context save/restore to be used, for example,
the extended context in rv32m1.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
After these wdog refactor:
We conducted a latency measurement using the rt-tests/cyclictest (commit cadd661) on an x86_64 NUC12 equipped with an i7-1255U processor and 16GB of LPDDR5 memory. The specific command used for this microbenchmark was cyclictest -q -l 100000 -h 30000, which is designed to assess the responsiveness of the cyclic timer.
The findings from our benchmark are summarized below, highlighting the minimum, median, and maximum latency values for each operating system tested:
Operating System Minimum Latency (us) Median Latency (us) Maximum Latency (us)
Linux 48 53 410
PreemptRT 6 57 148
Xenomai 53 53 64
NuttX 64 626 1212
NuttX (refactor) 1 1 3
In this table, "Min" indicates the shortest latency observed, "Median" represents the middle value of the latency distribution, and "Max" denotes the longest latency encountered.
The systems tested were as follows:
Linux: ACRN version 6.1.80 (commit f528146)
PreemptRT: Linux kernel 5.4.251 with the 5.4.254-rt85 patch applied
Xenomai: Linux kernel 5.4.251 patched with ipipe-core-5.4.239-x86-13
These results clearly demonstrate the varying performance of different operating systems in terms of timer latency, the refactored NuttX showing particularly low latency values.
Signed-off-by: ligd <liguiding1@xiaomi.com>
Now we have CONFIG_USEC_PER_TICK, and for our timer system, all the calculation used 'tick'.
And all the timespec should change to 'tick' before use wd_start(), so USEC2TICK() can NOT be avoided.
Then there must be an 'less then one tick' loss.
One resolution:
ticks++ anyway when wd_start(). But this will caused time expired more a tick.
Another resolution:
Change the testcase, and allow the following logic:
t1 = current_time();
sleep(3);
t2 = current_time();
allow: t2 - t1 >= 3;
(original test must be: t2- t1 > 3)
The original test think the time must be elapse-ing, and the (t2 - t1) must bigger then 3,
but in our system, we use 'tick' as the minimal wdog unit, then there must a precision loss.
Now we choose first resolution.
Signed-off-by: ligd <liguiding1@xiaomi.com>
