RISC-V permits myriad extensions to the ISA, any of which may imply
additional context that must be saved and restored on ISR entry and
exit. The current in-tree example is the Pulpino core, which has extra
registers used by ISA extensions for running loops that shouldn't get
clobbered by an ISR.
This is currently supported by including pulpino-specific definitions
in the generic architecture code. This works, but it's a bit inelegant
and is something of a layering violation. A more generic mechanism is
required to support other RISC-V SoCs with similar requirements
without cluttering the arch code too much.
Provide that by extending the semantics of the existing
CONFIG_RISCV_SOC_CONTEXT_SAVE option to allow other SoCs to allocate
space for saving and restoring their own state, promoting the
currently pulpino-specific __soc_save_context / __soc_restore_context
routines to a RISC-V arch API.
The cost of making this generic is two more instructions in each ISR
to pass the SoC specific context to these routines in a0 rather than
just assuming the stack points to the right place. This is minimal,
and should have been done anyway to keep with the ABI.
As a first (and currently only in-tree) customer, convert the Pulpino
SoC code to this new mechanism.
Signed-off-by: Marti Bolivar <marti@foundries.io>
These changes were obtained by running a script created by
Ulf Magnusson <Ulf.Magnusson@nordicsemi.no> for the following
specification:
1. Read the contents of all dts_fixup.h files in Zephyr
2. Check the left-hand side of the #define macros (i.e. the X in
#define X Y)
3. Check if that name is also the name of a Kconfig option
3.a If it is, then do nothing
3.b If it is not, then replace CONFIG_ with DT_ or add DT_ if it
has neither of these two prefixes
4. Replace the use of the changed #define in the code itself
(.c, .h, .ld)
Additionally, some tweaks had to be added to this script to catch some
of the macros used in the code in a parameterized form, e.g.:
- CONFIG_GPIO_STM32_GPIO##__SUFFIX##_BASE_ADDRESS
- CONFIG_UART_##idx##_TX_PIN
- I2C_SBCON_##_num##_BASE_ADDR
and to prevent adding DT_ prefix to the following symbols:
- FLASH_START
- FLASH_SIZE
- SRAM_START
- SRAM_SIZE
- _ROM_ADDR
- _ROM_SIZE
- _RAM_ADDR
- _RAM_SIZE
which are surprisingly also defined in some dts_fixup.h files.
Finally, some manual corrections had to be done as well:
- name##_IRQ -> DT_##name##_IRQ in uart_stm32.c
Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
All labels containing "_<8-hex-digits>_" or "16550_<3or6-hex-digits>_"
in their names, assumed to be generated by the extracting script,
are updated with the DT_ prefix, to reflect the recent changes made
to the script.
Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
Update the uart_miv driver to get params like name, addr, baud-rate,
clock freq from DTS generated defines. Fixup related board and soc code
as needed.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Add minimal DTS support for the m2gl025_miv. The dts just has the core,
SoC, PLIC, and UART described. We still get memory related info from
Kconfig.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
The Zephyr configuration system uses many different files in many
different formats. It makes it a lot easier for users to understand
what these files do if when we use the correct file extensions.
To this end we rename the dts.fixup files to the correct file
extension '.h'.
This is a breaking change for out-of-tree fixup files. Such files will
be detected and given an appropriate error message.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
The dts.fixup for the hifive1 board was not board specific but related
to the SoC. Move the dts.fixup into the SoC dir so any other boards
using this same SoC will take advantage of it.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Add the needed bits to get device tree support for the GPIO controller
on the Zedboard-Pulpino. This will allow us to move LED & button info
into the board.dts.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Add simple device tree support for the Pulpino SoC and Zedboard-Pulpino
board port. This gets the UART info from device tree instead of soc.h
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Move the SoC outside of the architecture tree and put them at the same
level as boards and architectures allowing both SoCs and boards to be
maintained outside the tree.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Marti Bolivar