CalypsoRomloader » History » Revision 8
Revision 7 (Anonymous, 02/19/2016 10:48 PM) → Revision 8/11 (Anonymous, 02/19/2016 10:48 PM)
[[PageOutline]] = CalypsoRomloader = The Romloader is a serial bootloader inside the maskrom of the Calypso/lite/plus DBB. It can be mapped to the reset-vector (0x000000) on the Calypso by pulling the nIBOOT pin to low, or via the EXTRA_CONF register, and if activated, it checks both UARTs (MODEM and IRDA) for incoming activation commands for a certain amount of time, if nothing is received, it checks if the powerbutton is still pressed, if yes it jumps to the application code in the flash memory.[[BR]] If the flash-memory is unprogrammed (checks a few flash locations for that), it stays activated and waits for incoming commands. So even on devices which use their own bootloader stored inside the flash, it could be activated by pulling nIBOOT low (but which is inaccessible on most phones). We have implemented support for interfacing this loader from our [wiki:osmocon] program. There are currently 3 known variants: == "non-secure"-Romloader on Calypso/lite == The "non-secure" variant, which is used on the Calypso/Calypso lite and which we support with osmocon. It doesn't require a "key". It is known to be used by the Motorola W220, BenQ Siemens A38, the OpenMoko devices (Neo 1973 & Freerunner), as well as on many other Calypso phones (LG, Bird). == "secure"-Romloader on Calypso/lite == This one ~~seems to be used on some newer Calypso batches~~, and is known to be used on the Alcatel VLE5 series. In order to activate it, you have to send a "key" (which seems to be the first block stored inside the flash). Basic reverse engineering is done, but nothing working yet, at least we know the "key" for the Alcatel VLE5 phones.[[BR]] '''Update:''' As it turned out, there is no secure loader on the Calypso sitting in the bootrom - Alcatel just put a slightly modified version of the Calypso plus secure loader in the flash. Thus, it's possible to load code when pulĺing nIBOOT to low, since then the regular romloader becomes active. == "secure"-Romloader on Calypso plus == This variant is very similar to the one on the Calypso, it requires a key, too, and has some different structure of the branch address. It also seems to cooperate in some way with a second loader stored inside the flash. We know the key for the Motorola C261 (which is manufactured by Compal). == Romloader support in osmocon == For downloading code to a romloader target, connect your serial cable as with the Compal devices, start osmocon with the "-m romload" switch, and push the power button shortly. Osmocon will activate the loader, download the code in blocks, submit a checksum and send a branch command to 0x820000. For instructions how anyone who wants to run try this out on an !OpenMoko OpenMoko device, see OpenMoko. use {{{ $ echo 0 >/sys/bus/platform/devices/neo1973-pm-gsm.0/power_on $ echo 1 >/sys/bus/platform/devices/neo1973-pm-gsm.0/power_on }}} to control the GSM Module. (We now have dedicated binaries for the OpenMoko devices) {{{ $ ./osmocon -p /dev/ttyUSB0 -m romload ../../target/firmware/board/gta0x/loader.osmoload.bin }}} * Push the power-on button of your phone (short push, not like a regular phone boot!) * Observe output resembling the following {{{ Sending beacon... Sending beacon... Sending beacon... Sending beacon... got 1 bytes from modem, data looks like: 3e got 1 bytes from modem, data looks like: 69 Received ident ack from phone, sending parameter sequence read_file(../../target/firmware/board/gta0x/loader.osmoload.bin): file_size=14580, hdr_len=0, dnload_len=14583 Received parameter ack from phone, starting download Used blocksize for download is 1024 bytes Preparing block 1, block checksum is 0x93 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 1 finished Received block ack from phone Preparing block 2, block checksum is 0x3b handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 2 finished Received block ack from phone Preparing block 3, block checksum is 0x79 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 3 finished Received block ack from phone Preparing block 4, block checksum is 0x83 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 4 finished Received block ack from phone Preparing block 5, block checksum is 0xe5 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 5 finished Received block ack from phone Preparing block 6, block checksum is 0x6a handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 6 finished Received block ack from phone Preparing block 7, block checksum is 0x98 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 7 finished Received block ack from phone Preparing block 8, block checksum is 0x86 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 8 finished Received block ack from phone Preparing block 9, block checksum is 0x0f handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 9 finished Received block ack from phone Preparing block 10, block checksum is 0xa1 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 10 finished Received block ack from phone Preparing block 11, block checksum is 0x07 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 11 finished Received block ack from phone Preparing block 12, block checksum is 0x5c handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 12 finished Received block ack from phone Preparing block 13, block checksum is 0x68 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 13 finished Received block ack from phone Preparing block 14, block checksum is 0x1c handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 14 finished Received block ack from phone Preparing the last block, filling 630 bytes, block checksum is 0x54 handle_write_block(): 1024 bytes (1024/1024) handle_write_block(): Block 15 finished Finished, sent 15 blocks in total Received block ack from phone Sending checksum: 0xdd Checksum on phone side matches, let's branch to your code Branching to 0x00820000 Received branch ack, your code is running now! OSMOCOM Calypso loader (revision 7025e5c-modified) ====================================================================== Running on gta0x in environment osmoload }}} == Note on OpenMoko and SHR == There is slight difference in device naming in SHR running on Neo Freerunner and Calypso chip might be more timing-sensitive so commands should be adjusted as follows: {{{ $ ./osmocon -i 13 -m romload -p /dev/ttySAC0 ../../target/firmware/board/gta0x/layer1.highram.bin }}} and {{{ echo 0 >/sys/bus/platform/devices/gta02-pm-gsm.0/power_on echo 1 >/sys/bus/platform/devices/gta02-pm-gsm.0/power_on }}} N. B. Make sure to check that nothing uses modem before executing commands above by running {{{ fuser /dev/ttySAC0 }}} AND disable ogsmd, ousaged, ophoned via /etc/frameworkd.conf fsogsmd could be prevented from accessing modem by commenting following variables in /etc/freesmartphone/conf/GTA02/fsogsmd.conf {{{ device_port modem_access }}}
