Multi-core

In Zephyr 3.2.0 see `zephyr/include/zephyr/drivers/ipm.h` for some starting points to understand inter-processor messaging.

• https://ostconf.com/system/attachments/files/000/001/688/original/Brodkin_Linux_Piter_presentation.pdf?1570035188

One of two or three Zephyr 3.2.0 sample apps which touch on multi-core firmware design:

• ./subsys/ipc/openamp/boards/lpcxpresso55s69_cpu0.overlay

^ Zephyr sys init run levels

Likely for another local article, excerpt from `zephyr/include/zephyr/init.h`:

 18 /*
 19  * System initialization levels. The PRE_KERNEL_1 and PRE_KERNEL_2 levels are
 20  * executed in the kernel's initialization context, which uses the interrupt
 21  * stack. The remaining levels are executed in the kernel's main task.
 22  */
 23 
 24 #define _SYS_INIT_LEVEL_PRE_KERNEL_1    0
 25 #define _SYS_INIT_LEVEL_PRE_KERNEL_2    1
 26 #define _SYS_INIT_LEVEL_POST_KERNEL     2
 27 #define _SYS_INIT_LEVEL_APPLICATION     3
 28 
 29 #ifdef CONFIG_SMP
 30 #define _SYS_INIT_LEVEL_SMP             4
 31 #endif

^ General MCU bring-up

NXP LPC55S69 system clock settings HAL source file:

$ vi ./hal/nxp/mcux/mcux-sdk/devices/LPC55S69/drivers/fsl_clock.h

^ NXP mailbox HAL files

modules/hal/nxp/mcux/mcux-sdk/drivers/mailbox/fsl_mailbox.h

Size of data block which mailbox can send:

$ grep -nr MCUX_IPM_DATA_REGS ./*
./nexus-gateway-firmware/samples/ipm_mcux/build/zephyr/zephyr.lst:8385:	return MCUX_IPM_DATA_REGS*sizeof(uint32_t);
./nexus-gateway-firmware/samples/ipm_mcux/build/zephyr/zephyr.lst:8433:	if (size > MCUX_IPM_DATA_REGS * sizeof(uint32_t)) {
./nexus-gateway-firmware/samples/ipm_mcux/build/ipm_mcux_remote-prefix/src/ipm_mcux_remote-build/zephyr/zephyr.lst:6266:	return MCUX_IPM_DATA_REGS*sizeof(uint32_t);
./nexus-gateway-firmware/samples/ipm_mcux/build/ipm_mcux_remote-prefix/src/ipm_mcux_remote-build/zephyr/zephyr.lst:6314:	if (size > MCUX_IPM_DATA_REGS * sizeof(uint32_t)) {
./tags:6361980:MCUX_IPM_DATA_REGS	zephyr/drivers/ipm/ipm_mcux.c	16;"	d	file:
./zephyr/drivers/ipm/ipm_mcux.c:16:#define MCUX_IPM_DATA_REGS 1
./zephyr/drivers/ipm/ipm_mcux.c:82:	uint32_t data32[MCUX_IPM_DATA_REGS]; /* Until we change API
./zephyr/drivers/ipm/ipm_mcux.c:94:	if (size > MCUX_IPM_DATA_REGS * sizeof(uint32_t)) {
./zephyr/drivers/ipm/ipm_mcux.c:117:	return MCUX_IPM_DATA_REGS*sizeof(uint32_t);
Binary file ./zephyr/drivers/ipm/.ipm_mcux.c.swp matches
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