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
This change improves build consistency across external projects integrated
through CMake by ensuring that compiler flags defined in configuration files
are passed correctly to the toolchain. It covers the majority of use cases,
as external projects are typically also CMake-based. For projects that use
a custom build system, users will still need to specify the required flags
manually.
This reverts earlier commit d2858847 and thereby making SPIRAM_USE_MEMMAP
available for all targets.
This config option has no direct usage but just avoids adding the PSRAM
to heap but still keeps it memory mapped.
Closes https://github.com/espressif/esp-idf/issues/17764
feat(esp_psram): Fix late PSRAM init and add some wasted XIP PSRAM memory in heap
Closes IDF-11463 and IDF-10555
See merge request espressif/esp-idf!37116
In case of ESP32-P4, if SPIRAM memory initialisations are not performed during
boot-up, XIP PSRAM can be setup because of different virtual range of PSRAM and Flash
