1. Modify esp_bt_controller_mem_release() to release BTDM BSS and Data to heap if
ESP_BT_MODE_BTDM mode is passed to it
2. Add a new API esp_bt_mem_release() which internally calls
esp_bt_controller_mem_release() with the provided mode and then if mode
is ESP_BT_MODE_BTDM, releases BT BSS and Data to heap.
Background:
For Wi-Fi and BT/BLE applications, for e.g. the usecase is like when
Bluetooth is used for provisioning and once the device is connected to the Wi-Fi
AP, we can turn off Bluetooth completely. In such scenarios, it should be possible to
reclaim all the memory of Bluetooth. Although, currently this does not
happen.
Experiment:
Made the following modifications to examples/bluetooth/gatt_server :
1. Added support of simple_wifi to it
2. Moved all the bluetooth related code under CONFIG_BT_ENABLED config
option
3. Calculated the free heap in 2 similar scenarios:
i. Disabled BT (CONFIG_BT_ENABLED undefined) and checked the free
heap after STA connected
ii. Kept BT enabled and disabled it after STA connected and checked
the free heap
Ideally, the numbers for i., ii. above should have been similar. But
there was a delta of almost 30-31K. (i. > ii.)
4. Through make size-components checked the common BSS for libbta.a and libbtdm_app.a
and found it to be almost 30K. Data is around 1K
Solution:
1. Modified the linker script to mark the BSS and Data for these libraries and
free it when ESP_BT_MODE_BTDM mode is passed to mem release APIs.
2. Verified that the free heap is comparable for i. and ii. above.
Note: It is known that once this is done, Bluetooth can only be used
again post reboot.
Signed-off-by: Hrishikesh Dhayagude <hrishi@espressif.com>
This change removes the earlier limitation of 1984 bytes for storing data-blobs.
Blobs larger than the sector size are split and stored on multiple sectors.
For this purpose, two new datatypes (multi-page index and multi-page data) are
added for entries stored in the sectors. The underlying read, write, erase and find
operations are modified to support these large blobs. The change is transparent
to users of the library and no special APIs need to be used to store these large
blobs.
* Fixes some "noreturn" functions in bootloader utils which did return (causing fatal CPU
exceptions).
* Marks bootloader entry as "noreturn", preventing "user code done" from stalling boot
Partial fix for https://github.com/espressif/esp-idf/issues/1814 TW20016
(Comprehensive fix for this issue will be enabling WDT during bootloader, coming shortly.)
Because address space is mapped in 64KB pages, it was possible for unauthenticated data after the
app .bin to become mapped into the flash cache address space.
This problem is solved by 2 changes:
* "esptool elf2image --secure-pad" will pad the image so that the signature block ends close to the
64KB boundary. Due to alignment constraints it will be 12 bytes too short after signing (but
with flash encryption, these 12 bytes are still encrypted as part of the last block and can't be
arbitrarily changed).
* By default, secure boot now requires all app partitions to be a multiple of 64KB in size.
