No idea if you find this information useful, started learning ARM architecture and assembly 2 days ago in turbo-mode, if this info seems to be nonsense, please ignore it. ;D
Bootloader level Modem_BootingStart procedure (as ELF headers says), no idea for what it is initialized in bootloading stage and if it is correct, commented as "DRV_Modem_Reset" by samsung debugstrings.
used procedures:
GPIO_Set_Config
GPIO_Set_Data
GPIO_Set_DrvStrength
GPIO_Set_PudPdn
PWM_Drv_Delay
pin 0x9B data 1
pin 0x9B config 1
pin 0xB3 data 1
pin 0xB3 config 1
delay 10000 (decimal, no idea about unit, most likely nanoseconds)
pin 0xAA drvStrength 3 (? )
pin 0xAA data 0
pin 0xAA config 1
delay 100000
pin 0xAA config 0
pin 0xAA PudPdn 0 (?)
delay 10000
pin B1 data 1
pin 0xB1 config 1
delay 100000
pin 0xB1 data 1
here comes loading whole dbl.mbn from 0x200000 NAND to RAM
haven't identified the rest enough to write it, it is call to "process_packets" (what packets?) and then UploadReset
I can only imagine what GPIO_Set_Data does. Totally no idea about set_config and driverstrength. I assume that Drv_Delay is just pausing execution and let Qualcomm chipset send&receive data, and unpause execution after timeout (10000 in this case) or getting ready-flag.
Admiting again i have almost no idea about how does it works, all i know that we've got like 78 General Purpose I/O pins which are physically connected to externals like radio, just trying to learn something and be helpful. Still reading about it as much as i can.
//edit: I assume that set_data prepare signal to be send, set_config turns on/off sending, then bootloader is waiting to make sure modem gets it.
Next assumption is that after reset regular transmission is being executed between Qualcomm+CPU behind and Modem, sending data stored in dbl.mbn to modem, maybe comparing reset-procedure to modem datasheet (any1 got it?) you can figure out those 4 pins atleast?
Probably mijoma will visit forum soon and get a heart attack after he read what bull**** I wrote, cuz i figured everything wrong or what. xP
//modem reset procedure looks equals in S8530, only dbl.mbn is written under 0x400000 instead of 0x200000.
