The hardware watchdog automatically shutdown the device after 10s of
inactivity, being defined as 10s without the tick IRQ fired (aka braindead
device).
The software IRQ mechanism is more interesting: it uses a very high priority
timer setup as one-shot to trigger after 5s of inactivity (but IRQ still
enabled). When detected, it patches the running code to insert a SWI
instruction so that on interrupt return it will trigger a SWI and produce
a meaningfull backtrace to debug the deadlock. This should allow to debug
freezes in IRQ context.
Change-Id: Ic55dad01201676bfb6dd79e78e535c6707cb88e6
Many imx233 targets boot in a very low performance mode, typically cpu and
dram at 24MHz. This results in very slow boots and very unstable USB
bootloader mode. Since cpu frequency scaling is disabled in bootloader in
rockbox, always make the frequency scaling code available and boost at boot
time.
Change-Id: Ie96623c00f7c4cd9a377b84dcb14b772558cfa4d
CPU frequency scaling is basically useless without scaling the
memory frequency. On the i.MX233, the EMI (external memory
interface) and DRAM blocks are responsable for the DDR settings.
This commits implements emi frequency scaling. Only some settings
are implemented and the timings values only apply to mDDR
(extracted from Sigmatel linux port) and have been checked to
work on the Fuze+ and Zen X-Fi2/3. This feature is still disabled
by default but I expected some battery life savings by boosting
higher to 454MHz and unboosting lower to 64MHz.
Note that changing the emi frequency is particularly tricky and
to avoid writing it entirely in assembly we rely on the compiler
to not use the stack except in the prolog and epilog (because
it's in dram which is disabled when doing the change) and to put
constant pools in iram which should always be true if the
compiler isn't completely dumb and since the code itself is put
in iram. If this proves to be insufficient, one can always switch
the stack to the irq stack since interrupts are disabled during
the change.
Change-Id: If6ef5357f7ff091130ca1063e48536c6028f23ba
This does not scale the EMI frequency and keep the processor
betweel 261MHz and 454MHz. It can still be improve. The auto-slow
divisor could still be change, 8 seems reasonable for now
Change-Id: I639bb3f6b7f8efedc7dc58d08127849156eeb1b6
The icoll code now has an IRQ storm detection mechanism which
will prevent the device from hard freezing in case it happen.
Change-Id: I9861238dce61d29af1e48f9c534ec63a7f23465c
- now identity map dram uncached and have a cached and buffered virtual alias
- rework dma to handle virtual to physical pointers conversion
- fix lcd frame pointer
- implement usb detection properly
- implement bootloader usb properly
- allow the bootloader to disable MMC windowing (useful for recovery)
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30432 a1c6a512-1295-4272-9138-f99709370657
