--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/Config-vars	Tue Jul 24 04:22:51 2018 +0000
@@ -0,0 +1,143 @@
+The following Bourne shell variables can be set on the ./configure.sh command
+line to tweak the firmware build configuration:
+
+ALLOW_CSIM_GSM
+
+	Per TI's original design, the AT+CSIM command does not allow GSM APDUs
+	of class 0xA0.  Openmoko found some need for them, and they patched
+	their modem fw to allow these APDUs with AT+CSIM.  With our new hybrid
+	modem fw this policy setting is configurable at build time; the default
+	is ALLOW_CSIM_GSM=1 (GSM APDUs allowed).
+
+DISABLE_SLEEP
+
+	The general default is DISABLE_SLEEP=0, and the firmware automatically
+	enables all of the chipset's available sleep modes on boot.  Setting
+	DISABLE_SLEEP=1 causes all sleep modes to be disabled by default on
+	boot (they can still be enabled with the AT%SLEEP command); this
+	setting is needed for FCDEV3B V1 boards that have a hardware bug that
+	causes breakage when sleep modes are enabled.
+
+DSAMPLE_FULL_COLOR
+
+	When the firmware's R2D component (normally present only in UI-enabled
+	builds) is built for any target other than c139, one of TI's D-Sample
+	framebuffer drivers is enabled: either color or B&W.  (The actual
+	hardware pokes are omitted when the build target is anything other than
+	dsample, but the framebuffer is still maintained in RAM.)  By default
+	the color framebuffer driver is enabled; setting DSAMPLE_FULL_COLOR=0
+	switches to the B&W framebuffer driver.
+
+L1_DYN_DSP_DWNLD
+
+	This setting enables TI's dynamic DSP patch download mechanism.  When
+	the firmware is built for a Calypso target with DSP ROM version 36 in
+	the silicon (all FreeCalypso-made hw and most of the supported legacy
+	targets), L1_DYN_DSP_DWNLD is enabled by default and needs to be kept
+	enabled for correct operation: the patch code we got from TI for this
+	ROM is the dynamic download version, and the ARM-side L1 code expects
+	all of these patches to be present, both the static part and the
+	dynamic parts.  However, one can build our fw with L1_DYN_DSP_DWNLD=0
+	for experimental testing, to see what breaks when the dynamic patches
+	are omitted.
+
+L1_VOICE_MEMO_AMR
+
+	This setting enables or disables support in L1 and in the RiViera Audio
+	Service for AMR voice memo recording and playback.  This code has not
+	been properly studied yet and no test AT commands are provided for it,
+	but it is enabled by default like in TI's original TCS211 fw.
+
+MELODY_E2
+
+	This setting enables or disables support in L1 and in the RiViera Audio
+	Service for playing E2-format melodies.  The default is MELODY_E2=1
+	like in TI's original TCS211 fw.  Note that Melody E1 support is always
+	enabled; setting MELODY_E2=0 disables only Melody E2, but not E1.
+
+SERIAL_DYNAMIC_SWITCH
+
+	TI's TCS211 fw includes a provision (only for Bluetooth-enabled fw in
+	TI's original) to switch one UART between the AT command interface and
+	RVTMUX while the other UART is fixed for Bluetooth.  In FreeCalypso we
+	have changed this code to work without Bluetooth, for the purpose of
+	switching the user-facing MODEM UART between AT commands and RVTMUX,
+	but the mechanism does not work properly yet and is disabled by default.
+	Enable it with SERIAL_DYNAMIC_SWITCH=1 if you would like to play with
+	it.
+
+SPEECH_RECO
+
+	This setting enables or disables support in L1 and in the RiViera Audio
+	Service for TI's speech recognition mechanism.  This code and the
+	underlying DSP facility itself have not been properly studied yet and
+	no test AT commands are provided for it, but it is enabled by default
+	like in TI's original TCS211 fw.
+
+SUFFIX
+
+	This setting is solely for configuration management.  If you make a
+	build with any of the settings described in this document changed from
+	the default, you should also pass a SUFFIX=-xxx argument so your special
+	build will be appropriately identified in the build directory name and
+	in the firmware version ID string compiled into the image.  The naming
+	of suffixes is up to you, but here are some examples:
+
+	DSAMPLE_FULL_COLOR=0 UI_CONFIG=bigbw SUFFIX=-bw
+	L1_DYN_DSP_DWNLD=0 SUFFIX=-nodyn
+	MELODY_E2=0 SUFFIX=-noe2
+	SERIAL_DYNAMIC_SWITCH=1 SUFFIX=-sds
+	SPEECH_RECO=0 SUFFIX=-nosr
+	TR_BAUD_CONFIG=TR_BAUD_812500 SUFFIX=-812500
+	USE_STR2IND=1 SUFFIX=-s2i
+
+TR_BAUD_CONFIG
+
+	The value of this symbol is an alphanumeric keyword of the form
+	TR_BAUD_xxxxxx; the default is TR_BAUD_115200.  See
+	src/cs/drivers/drv_core/uart/traceswitch.h for the available baud rate
+	choices; the most practical use is setting TR_BAUD_CONFIG=TR_BAUD_812500
+	when you need to run the RVTMUX serial channel at the maximum possible
+	baud rate.
+
+UI_CONFIG
+
+	The 3 allowed values for this setting are bigcolor, bigbw and 84x48,
+	selecting one of the 3 UI configurations supported by TI's code.  The
+	default is 84x48 when the firmware is built for target c11x or c139,
+	and bigcolor otherwise.
+
+USE_STR2IND
+
+	Unlike TI's original firmwares, we build without str2ind by default.
+	You can enable str2ind with USE_STR2IND=1, but the time to build the fw
+	will be significantly longer as the compiler has to be run twice for
+	each C source file, with str2ind sandwiched in between.
+
+The following Bourne shell variables are used inside the build system in the
+individual component build recipes (components/*) but cannot be set on the
+./configure.sh line because they are fixed in the overall fw build recipes
+(configs/*):
+
+GPRS
+
+	Self-explanatory: enables or disables GPRS.
+
+MMI
+
+	TI's original config variable: MMI=0 for the AT-command-controlled
+	modem configuration or MMI=2 for the UI-enabled configuration with
+	BMI and MFW.
+
+SRVC
+
+	TI's original config variable, selects the presence or absence of data
+	services other than GPRS as follows:
+
+	SRVC=0: voice and SMS only
+	SRVC=1: CSD and fax enabled
+	SRVC=2: CSD enabled, but not fax
+
+Finally, CHIPSET, DSP, RF and AMR variables reflect the physical configuration
+of the selected target hw that no amount of software hacking can change.
+(The AMR variable indicates the presence or absence of AMR support in the DSP.)