nuttx/arch
Lourens Naude bc44441f9d arch/arm/src/imxrt: Add an RPTUN backend for the RT1170 CM4.
The i.MX RT1176 pairs the Cortex-M7 with a Cortex-M4 that NuttX left
in ROM-held reset.  This backend lets NuttX on the CM7 run the CM4 as
an RPTUN remote.  The loader writes the CM4 ELF through the LMEM
backdoor window, the boot vector goes into IOMUXC_LPSR_GPR0/1 as the
backdoor alias of the code TCM (the CM4-native address does not boot,
which NXP's MCMGR also assumes), and SRC releases the core.

A released slice cannot be held in reset again: a software reset is a
pulse after which the core restarts from the boot vector.  Stop
therefore parks the core in a wfi loop written over the start of its
image, and the next start reloads the image.

Virtqueue kicks travel on MU-A channel 0.  A kick into a full mailbox
is coalesced, because the remote rescans every virtqueue on any kick.
SRC_SRMR is set so a CM4 lockup resets only the CM4 instead of the
whole chip.

The board supplies the remote name, the ELF path, the address
environment, the boot vector and the autostart choice through
imxrt_rptun_init().  Gated by IMXRT_HAVE_CM4, which only the
MIMXRT1176 selects; selects DEV_SIMPLE_ADDRENV for libmetal.

Assisted-by: Claude:claude-fable-5-1
Signed-off-by: Lourens Naude <lourens@bearmetal.eu>
2026-10-10 02:12:26 +08:00
..
arm arch/arm/src/imxrt: Add an RPTUN backend for the RT1170 CM4. 2026-10-10 02:12:26 +08:00
arm64 arch/arm64: Map a region that does not start at a page table boundary. 2026-10-09 11:20:33 -03:00
avr arch, boards, cmake: Build C++ ELF modules without __cxa_atexit. 2026-09-04 15:44:24 -03:00
ceva arch/atomic: remove up_testset in spinlock 2026-09-08 08:58:54 +08:00
dummy
hc tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
mips arch/mips/pic32mz: support GPIO interrupts on the PIC32MZ-W1. 2026-10-09 17:55:25 +08:00
misoc arch, boards, cmake: Build C++ ELF modules without __cxa_atexit. 2026-09-04 15:44:24 -03:00
or1k arch, boards, cmake: Build C++ ELF modules without __cxa_atexit. 2026-09-04 15:44:24 -03:00
renesas nuttx/libc: refine the atomic related Kconfig 2026-08-24 13:20:45 +08:00
risc-v arch: Let pgalloc() extend the selected address environment. 2026-10-09 06:10:52 -03:00
sim arch/sim/src/sim/posix/sim_tapdev.c: drop the frame on a TAP write error. 2026-10-09 15:04:22 -03:00
sparc arch/atomic: remove up_testset in spinlock 2026-09-08 08:58:54 +08:00
tricore arch/atomic: remove up_testset in spinlock 2026-09-08 08:58:54 +08:00
x86 arch/x86: Add -P to CPP to suppress linemarkers. 2026-09-17 16:21:59 +08:00
x86_64 arch/x86_64/intel64: attach shared vector handlers only once. 2026-10-09 22:39:22 +08:00
xtensa arch/xtensa/esp32s3: Make SPI CS, MOSI and MISO pins signed. 2026-10-09 18:29:04 +08:00
z16 tools: fix stale archive members surviving a Kconfig-driven CSRCS change 2026-07-28 21:26:03 -03:00
z80
CMakeLists.txt cmake: Use NUTTX(_DIR/_BIN_DIR) instead CMAKE(_SRC_DIR/_BIN_DIR) 2026-08-09 11:13:08 -03:00
Kconfig arch/arm64: Implement up_addrenv_fork() and provide POSIX fork(). 2026-10-08 09:35:07 -03:00