FreeCalypso > hg > freecalypso-tools

comparison doc/Target-boot-control @ 582:deda54106c0e

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
doc/Target-boot-control: first draft
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 03 Feb 2020 01:25:31 +0000
parents
children d3e2b23ebf1d
comparison
equal deleted inserted replaced
581:d43dc6dfb44c 582:deda54106c0e
1 There is a new feature in loadtools (fc-loadtool & friends) and rvinterf as of
2 fc-host-tools-r12: target boot control. In a typical development environment
3 where FC host tools run on a general-purpose PC or laptop and communicate with
4 various Calypso targets via general-purpose serial or USB-serial ports, adapters
5 and cables, there is generally no way for the host computer running FC host
6 tools to directly command the Calypso target to power on and/or reboot - instead
7 such control must be performed "out of band" by the operator pressing the PWON
8 or RESET button on the target device; some targets may even require complex
9 battery manipulations. However, there may be more elaborate (less casual)
10 setups where FC host tools run on a special kind of host system which does have
11 some means to directly control power and reset to an associated Calypso target:
12
13 * The Mother has a plan to produce a special FreeCalypso UART+JTAG Adapter, or
14 FC-UJA. This FC-UJA will be a special FT2232D adapter whose Channel A will
15 operate in MPSSE mode, connecting to the Calypso target's JTAG and nTESTRESET
16 signals, whereas Channel B will act as a standard UART, i.e., a ttyUSB device.
17 This FC-UJA needs to be built as a prerequisite before embarking on the
18 ambitious HSMBP (Handset Motherboard Prototype) project, as the special
19 adapter will be required for working with the HSMBP in development. When
20 FC-UJA becomes a reality, FC host tools running on a development host with
21 this adapter will need to be given the ability to issue nTESTRESET pulses to
22 the target through the adapter's MPSSE+GPIO channel; this nTESTRESET pulse
23 will cause the Calypso target to deep-reset, power on and boot.
24
25 * FC host tools (particularly fc-loadtool) may run on the application processor
26 of a smartphone such as Openmoko GTA02. In such environments the AP will have
27 special ad hoc control signals (typically GPIOs) to the modem, at the minimum
28 controlling the modem's PWON line. OM GTA02 added an overriding control of
29 overall power to the modem; other designs may reasonably add control of the
30 modem's RESET line.
31
32 * There may be special commercial applications in which one or more Calypso
33 modems are subservient to a control processor that acts similarly to the AP
34 of a smartphone, with that control processor not only communicating with its
35 slave modems via UARTs, but also controlling their power and reset.
36
37 Where does the desire for target boot control in loadtools and rvinterf come
38 from? Consider the conventional usage model where no target boot control
39 exists: you first run fc-loadtool or fc-iram or fc-xram or rvinterf on your
40 target /dev/ttyXXX, then press the PWON or RESET button on the target. Now
41 suppose that the finger-actuated button has been replaced with some magic
42 command that can be executed on the host system to produce the same effect -
43 now what? If the usage model stays the same, then you have to first run your
44 fc-loadtool or fc-iram or fc-xram or rvinterf command same as before, then as
45 it sits there waiting for the target to boot, you have to open another terminal
46 window, get another ssh session into the system or whatever, and run the magic
47 command that replaces the manual button press. Very cumbersome, hence the
48 desire for a better way.
49
50 Support for target boot control in FC host tools consists of a new -P option
51 implemented in all of loadtools programs and in rvinterf, as well as a special
52 configuration file which needs to be manually created. The working model is as
53 follows:
54
55 * There exist one or more "magic commands": a magic command is any shell command
56 (anything that can be passed to /bin/sh -c) whose execution causes a connected
57 Calypso target device to power on and boot. Naturally these commands will be
58 very specific to your custom system; they are NOT part of FC host tools!
59
60 * These magic commands may be long, and requiring the user to include each magic
61 command in full on fc-loadtool, rvinterf etc invokation lines is undesirable.
62 To save typing, we associate a short name (which you choose yourself as you
63 see fit) with each magic command, and we have a configuration file (which you
64 need to create) that defines the mapping.
65
66 * The argument to the new -P option is the short name to be looked up in the
67 configuration file.
68
69 The configuration file needs to be created in /opt/freecalypso/bootctrl.conf;
70 let us illustrate it with some examples.
71
72 Example 1: FC-UJA
73 =================
74
75 When FC-UJA becomes a reality, there will be a program called fc-testreset that
76 will locate the attached FC-UJA by its USB ID, connect to FT2232D Channel A and
77 generate the desired reset pulse on its output. The configuration in
78 /opt/freecalypso/bootctrl.conf may look as follows:
79
80 uja fc-testreset
81
82 This configuration associates boot control name 'uja' with shell command
83 fc-testreset. A developer would then run fc-loadtool like this:
84
85 fc-loadtool -h fcfam -Puja /dev/ttyUSB0
86
87 if ttyUSB0 is where FC-UJA's UART channel ended up. fc-loadtool would run
88 normally, sending beacons to /dev/ttyUSB0 and waiting for a Calypso boot ROM
89 response, but it would also execute the fc-testreset command listed in the
90 configuration file, and if everything is connected correctly, the resulting
91 nTESTRESET pulse will cause the target to boot.
92
93 The possibility of a single host talking to multiple Calypso targets is fully
94 supported: if you have multiple FC-UJA adapters with different USB descriptor
95 serial numbers programmed in their EEPROMs connected to respective Calypso
96 targets, you could have a /opt/freecalypso/bootctrl.conf setup like this:
97
98 uja1 fc-testreset -d serial1
99 uja2 fc-testreset -d serial2
100
101 and then run fc-loadtool accordingly:
102
103 fc-loadtool -h fcfam -Puja1 /dev/ttyUSB3
104 fc-loadtool -h fcfam -Puja2 /dev/ttyUSB4