emBLOD is Marcus Jansson's second-stage boot loader for AVR32UC3A
parts as used in the EVK1100 and Mizar32 boards, designed to allow
firmware images larger than the on-chip flash memory by loading the
eLua binary from SD card into SDRAM and executing it there.
The source for the emBLOD loader is here https://github.com/cmp1084/emBLOD
When compilation option bootloader=emblod is given to scons, a special
version is compiled that
- locates the program at the start of SDRAM
- doesn't initialize the system clocks and SDRAM controller, as these
are already set up by emBLOD.
If the bootloader= option is not given, eLua is compiled exactly as before.
The changes I've made to Marcus' originally posted patches are to put
DATA and BSS in internal static RAM, the same as before, since in the
best case (memcpy) the SDRAM is three times slower than access to
static RAM
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=80657
This also has an impact on code speed: the interpreter runs 9 times
slower in external SDRAM than it does in internal flash.
Tested and working on Mizar32
- add basic (no clock support) ADC implementation for AVR32, works on EVK1100
- add avr32-unknown-none-gcc to new lua-based build system to support crosstools-ng avr32 toolchain
The files that will be compiled to link an eLua image are now found automatically,
there's no need to specify them explicitly anymore. This applies only to the main
'build_elua.lua' build file, each target's 'conf.lua' still needs to specify them
explicitly (but can use the same automatic source file finding as the main build file).
$ lua build_elua.lua board=et-stm32 burn /dev/ttyUSB0
will invoke stm32ld (the default for stm32's platform 'burn' target) on port /dev/ttyUSB0.
I really have to document all this stuff somewhere. Don't panic though, for now you can use the old build system exactly like you used it before :)
- added support for per-backend targets. avr32 now has a 'burn' target (besides the regular 'prog') that can be used to build the image and burn it to the board (lua build_elua.lua board=atevk1100 burn). It is created in 'conf.lua'
- other fixes and improvements to the build system
