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.
This commit gives basic mmu driver framework. Now it is able to maintain
mmu virtual address usage on esp32, esp32s2 and esp32s3. Usage to
external virtual address should rely on mmu functions to know which
address range is available, instead of hardcoded.
This commit also improves psram memory that is added to the heap
allocator. Now it's added to the heap, according to the memory
alignment.
Closes https://github.com/espressif/esp-idf/issues/8295
Prior to this commit, esp_psram/include/esp_private/mmu.h contains some
APIs that is used for:
- copy flash content to psram
- necessary sync APIs used by flash_mmap.c, due to above feature
This commit rename it to mmu_psram_flash.h, therefore mmu.h can be used
for real mmu related APIs.
This commit also moves above mention funcitons in `mmu.c` and
`mmu_psram.c` to `mmu_psram_flash.c`, leaving `mmu.c` to be used for
real mmu driver.
