diff --git a/configs/esp32-core/README.txt b/configs/esp32-core/README.txt index 6d7e09c4b6..75fcf9442a 100644 --- a/configs/esp32-core/README.txt +++ b/configs/esp32-core/README.txt @@ -149,10 +149,10 @@ Memory Map FLASH: 0x400d0018 0x40400018 RX iram0_2_seg (actually FLASH) RTC slow memory: 0x50000000 0x50001000 RW rtc_slow_seg (NOTE 3) - NOTE 1: Linker script will reserved space at the beginning of the segment + NOTE 1: Linker script will reserve space at the beginning of the segment for BT and at the end for trace memory. NOTE 2: Heap enads at the top of dram0_0_seg - NOTE 3: Linker script will reserved space at the beginning of the segment + NOTE 3: Linker script will reserve space at the beginning of the segment for co-processor reserve memory and at the end for ULP coprocessor reserve memory. @@ -330,10 +330,12 @@ Things to Do ============ 1. There is no support for an interrupt stack yet. + 2. There is no clock intialization logic in place. This depends on logic in Expressif libriaries. The board comes up using that basic 40 Mhz crystal for clocking. Getting to 80 MHz will require clocking initialization in esp32_clockconfig.c. + 3. I did not implement the lazy co-processor save logic supported by Xtensa. That logic works like this: @@ -344,7 +346,9 @@ Things to Do c. The co-processor exception handler re-enables the co-processor. Instead, the NuttX logic saves and restores CPENABLE on each context - switch. + switch. This has disadvantages in that (1) co-processor context will + be saved and restored even if the co-processor was never used, and (2) + tasks must explicitly enable and disable co-processors. 4. Currently the Xtensa port copies register state save information from the stack into the TCB. A more efficient alternative would be to just