AVR uses Hardward architecture with separate address space for program
memory (flash) and data memory (RAM). Normal program flow can only
access data memory which means that all variables - including const
variables - have to be copied into RAM to be accessible. (This happens
automatically during startup.)
It is possible to work around this limitation in software but that
can have severe impact on performance and/or API complexity. It is hardly
feasible to change NuttX interfaces in a way that would allow to make use
of this workaround.
On newer AVR families, there is an alternative option enabled by this patch.
These chips map part of their program memory (a 32kB window) into data
memory address space. This patch leverages this feature and adds support
for placing const variables into the mapped window. No copy to RAM is done
for them.
Const variables are therefore loaded directly from flash (not consuming
RAM) while still being available to be used by any NuttX interface.
Linker script of breadxavr board is changed to make use of these changes.
Tested by verifying string addresses - parameters in printf call
in a custom application (and also by running the application and verifying
its output.)
Documentation tested by build.
Signed-off-by: Kerogit <kr.git@kerogit.eu>
This patch adds a document that describes why const variables need to be
copied into the RAM in AVR architecture for normal program flow in NuttX.
It then describes options of accessing them directly from the flash without
need to do any copying.
Patch was tested by building the documentation.
Signed-off-by: Kerogit <kr.git@kerogit.eu>
This commit removes the termios dependency of the command to set fix
rate. It makes the MINMEA dependency present in the Kconfig options for
the driver, and it also adds a retry limit to the boot message
verification of 3 times. The documentation has been updated to reflect
the correct signature for the registration function and fix some
formatting.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
This commit adds SD card support to the WeAct STM32H743 board configuration.
The implementation enables the board to interface with SD cards through the
SDMMC peripheral, allowing file system operations and data storage capabilities.
Signed-off-by: Jorge Guzman <jorge.gzm@gmail.com>
This commit makes it clear how to use the refresh.sh script to
update board configs showing differents usages cenarios.
Signed-off-by: Alan C. Assis <acassis@gmail.com>
This commit adds the lowerhalf driver support for the I2C Slave.
While not currently ideal, it is compatible with the upperhalf i2c slave driver.
A workqueue can be used to delegate the isr work to the upperhalf driver.
But keep in mind wq introduces a lot of delay and in certain scenarios,
it is better to write your own better upperhalf driver.
Signed-off-by: Stepan Pressl <pressl.stepan@gmail.com>
follow up this change:
commit 84dc88730c
Author: Xiang Xiao <xiaoxiang@xiaomi.com>
Date: Mon Jun 9 14:39:03 2025 +0800
libc: Move stream printf/scanf from libc/stdio to libc/stream
to keep all related code in one place
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
The documentation for `syslogd` is now updated to reflect its use of
`posix_spawn` to run the daemon in the background.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
Introduces two documentation additions. First, the RFC 5424 support is
documented on the main syslog documentation page, with information about
how to use it effectively. Second is the application documentation for
the `syslogd` application addition, which enables easy use of the new
RFC 5424 support.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
Add a page in the documentation listing supported and unsupported POSIX options.
This is the first step to support POSIX Application Environment Profiles.
Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
Rewrite parts of the two ELF guides to use scripts included in the
export archive and modernize some deprecated tools and Bash idioms.
Also add the new sphinx_collapse extension to the docs build config.
Signed-off-by: Niccolò Maggioni <nicco.maggioni+nuttx@gmail.com>
Introduces a commit message template with instructions in the
contributing documentation about how to set it up. This way users are
reminded of what makes a "good" NuttX commit as they write their commit,
and don't need to re-consult the documentation every time.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
Add `nuttx_versions` back into the `html_context` variable after it was
re-defined in #16440 to include more options. This fixes the failing
Pphinx autobuild.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
This commit adds the missing documentation for the ioctl command ANIOC_ADS1115_READ_CHANNEL.
Signed-off-by: Tony Lin <99093620+justapotato213@users.noreply.github.com>
This commit changed the type of the delay ticks to the unsigned, which can reduce the useless branch conditions
Besides, this commit added max delay tick limitation to fix incorrect timing behavior if we delay SCLOCK_MAX in the SMP build.
Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
This enables the use of the cryptographic accelerator within
the ESP32. The support algorithms are: SHA1, SHA256, SHA384
and SHA512.
Signed-off-by: Vlad Pruteanu <pruteanuvlad1611@yahoo.com>
Migrated teensy 2.0 README.txt to RST format. Moved common tool-chain
information to the chip page and provided back-link.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
This implements an interrupt-based SPI driver for the BCM2711 SPI
interfaces (excluding auxiliary SPI interfaces). Only tested on SPI0
since proprietary firmware does not initialize any other SPI interfaces,
and doing so will require reverse engineering.
