The previous wording "top of PSRAM" was ambiguous: the carve-out is
actually mapped at the highest physical addresses of PSRAM (after the
rodata, text, and main heap mappings). Update the Kconfig help text for
SPIRAM_ENC_EXEMPT and SPIRAM_ENC_EXEMPT_SIZE, the External RAM
documentation, and the internal layout comment to say "upper end of PSRAM
(highest physical addresses)" instead.
Drivers that allocate from the unencrypted PSRAM carve-out via
MALLOC_CAP_SPIRAM_NO_ENC currently have no way to verify after the fact
which pool a buffer came from. This is particularly relevant for callers
using heap_caps_malloc_prefer(MALLOC_CAP_SPIRAM_NO_ENC, MALLOC_CAP_SPIRAM),
where a silent fallback to encrypted PSRAM would still pass the typical
esp_ptr_external_ram() check.
Expose esp_psram_ptr_is_no_enc() in the public esp_psram.h header. It
performs a range check against the carve-out's virtual-address window and
returns false when PSRAM is not initialized or CONFIG_SPIRAM_ENC_EXEMPT is
disabled, so callers do not need to guard the call site with #if.
Also reference the helper from the External RAM documentation alongside
the heap_caps_malloc(MALLOC_CAP_SPIRAM_NO_ENC) usage example.
If the virtual-address pool is exhausted when reserving the unencrypted
PSRAM carve-out (the warning at L388 may already have fired for the main
mapping), esp_mmu_map_reserve_block_with_caps() returns an error rather
than aborting. Convert the previous assert() into a logged fallback that
disables the carve-out for this boot, mirroring the SPIRAM_ENC_EXEMPT_SIZE
>= psram_available_size path.
Also extend esp_psram_extram_test() to run the standard memory test on
the carve-out region when CONFIG_SPIRAM_ENC_EXEMPT is enabled, so the
unencrypted mapping is exercised on startup like the other PSRAM regions.
Extends the External RAM encryption section to describe
CONFIG_SPIRAM_ENC_EXEMPT and the MALLOC_CAP_SPIRAM_NO_ENC heap
capability, including a security warning and a typical DMA-alignment
use case. Mirrors the change in zh_CN.
Adds CONFIG_SPIRAM_ENC_EXEMPT, available on chips that support per-page
PSRAM encryption configuration (esp32c5, esp32c61, esp32p4). When
enabled, esp_psram carves CONFIG_SPIRAM_ENC_EXEMPT_SIZE off the top of
PSRAM and maps it via the new mmu_hal_map_region_no_enc() helper, which
writes MMU entries without the SENSITIVE bit. The region is registered
as a separate heap pool reachable only through the new
MALLOC_CAP_SPIRAM_NO_ENC capability bit, so default SPIRAM allocations
cannot accidentally land there.
PSRAM encryption imposes alignment constraints that some DMA engines
(e.g. 2D-DMA) cannot satisfy. This option lets such workloads place
their buffers in unencrypted PSRAM while keeping the rest of PSRAM
(and flash) encrypted. Default disabled; security implications are
documented in the Kconfig help text.
A typical scenario is: when XIP on PSRAM enabled, compiler optimization level is Os. Under certain binary layout, boot hangs and backtrace points to `esp_sleep_config_gpio_isolate`.
The root cause is that, during PSRAM initialization, it calls esp_gpio_reserve, which happens to place before the reported function. However, after call, there is no barrier before the clock adjustment in `mspi_timing_enter_low_speed_mode`. The clock gets changed when the cache is still fetching data, resulting in the corrupted data in the end of the cache line.
This commits add spi_flash_disable_cache as a barrier to make sure the cache transactions is finished before the clock switch.
Clarify that MALLOC_CAP_DEFAULT describes a memory capability
rather than the malloc() placement policy, so PSRAM-backed
capability allocations are documented correctly when malloc()
remains internal-only by default.
Closes https://github.com/espressif/esp-idf/issues/18391
Made-with: Cursor
- Removed conditional definitions for various RCC_ATOMIC macros across
multiple files, replacing them with a unified PERIPH_RCC_ATOMIC() macro.
- Updated instances where specific RCC_ATOMIC macros were used to ensure
consistent usage of PERIPH_RCC_ATOMIC().
- Deleted unused uart_share_hw_ctrl.h file as its functionality is now
integrated into the new structure.
