Add a 'make start' target which starts Rockbox using a
debugger. This only works to load the main binary, but
makes it much faster to test changes that don't affect
plugins/codecs.
Because SDRAM isn't accessible at reset and the main
binary is usually too big to fit in SRAM, the bootloader
must be flashed first before Rockbox can be loaded in
this way.
The boot protocol involves GDB writing a check pattern
to SRAM while the CPU is held in reset. The bootloader
detects the pattern and takes a breakpoint, by which
time SDRAM is accessible; GDB can then upload a binary
ELF image (copied as a raw file, since the ELF will be
loaded using RB's ELF loader) and leave the breakpoint
to continue booting.
From there the bootloader can load the ELF binary from
memory, exactly like a normal SD card boot.
Change-Id: I4eb971b4162ea422e38660455cfa0958cefaa18d
This replaces the gdb & openocd config in utils/stm32tools
and is easier to use. Remove the srst workaround; it seems
this was caused by the D1/D3 domains not being powered up
while the CPU was in sleep mode.
Change-Id: I28cc0273b3004c6e3146bb2447f0655cad8bb1c2
