- Wed Sep 03, 2014 2:05 pm
#146
From "what we know so far"
if this is correct we should see the Flash startup configuration on all common boards, right?
To give you some guidance on my thoughts:
from the "esp_iot_sdk_v0.6 / include / eagle_soc.h" file we know:
GPIO15 = TDO, other pins are obvious from the (not so good) schematic.
by the looks of it, no pulling resistors on GPIOs 15, 2 and 0 are present --> internal pulling resitors are used to trigger this configuration without external components.
To boot from UART:
GPIO0 must be pulled low. ... so soldering is required here. But this should be it (besides guessing the correct baudrate for the bootloader, but the variations are finite)!
Once one has accomplished this soldering, the XTCOM_UTILITY from the VM can be used to:
*does some one know a trick to automate the writing and reading to/from windows forms like the one used in XTCOM_UTIL? would be nice to dump the internal ROM contents address by address
all this is pure speculation based on some experiences i've made so far with other ICs. feel free to correct me
Squonk wrote:From the cited document, the available bootstraps are:
- GPIO15=1 => SDCard startup
- GPIO15=0 + GPIO2=1 + GPIO0=0 => UART download
- GPIO15=0 + GPIO2=1 + GPIO0=1 => Flash startup
if this is correct we should see the Flash startup configuration on all common boards, right?
To give you some guidance on my thoughts:
from the "esp_iot_sdk_v0.6 / include / eagle_soc.h" file we know:
GPIO15 = TDO, other pins are obvious from the (not so good) schematic.
by the looks of it, no pulling resistors on GPIOs 15, 2 and 0 are present --> internal pulling resitors are used to trigger this configuration without external components.
To boot from UART:
GPIO0 must be pulled low. ... so soldering is required here. But this should be it (besides guessing the correct baudrate for the bootloader, but the variations are finite)!
Once one has accomplished this soldering, the XTCOM_UTILITY from the VM can be used to:
- program the SPI flash
- read from arbitrary adress (dumping internal ROM for later using in QEMU
)* - load application binary to ram and run it
- other options shown in the XTCOM_UTILITY
*does some one know a trick to automate the writing and reading to/from windows forms like the one used in XTCOM_UTIL? would be nice to dump the internal ROM contents address by address
all this is pure speculation based on some experiences i've made so far with other ICs. feel free to correct me
