Framebuffer access consumes a lot of SDRAM bandwidth.
Moving it to AXI SRAM should be a big improvement as
it's around 8x faster (2x clock speed, 4x bus width).
Also take advantage of explicitly assigning sections
to the special :NONE segment, which means they will
not appear in any ELF program header and thus aren't
visible to the bootloader. They can then overlap
areas used by the bootloader -- by the time they're
written, the bootloader will be long gone -- making
it easier to make efficient use of SRAM.
Change-Id: I2392fd23b17472cc08dc5fe4556f6def3cc186ed
To avoid problems with SDMMC DMA not being able to
access all SRAMs equally, the ELF binary is loaded
at the top of SDRAM and then copied into place.
Change-Id: Icf16d02bc15605539cbe781dd27709225abca8f9
Note that USB current limiting is more or less wishful
thinking; only the charge current is limited, but the
system could easily draw more than 100 mA by itself.
Change-Id: I1083b015f0abea5a39a602ca8d7b142d3613b46b
Enable high speed USB for the Echo R1. Includes reasonably
complete support for full speed USB on the STM32H743 since
that was necessary to debug why it wasn't working at first
(which turned out to be a bug in memcpy, not a hardware or
driver issue).
Change-Id: Ie713195b22ba88c79b9b0d6eb289cb9ccd2763c2
Enable pullups on SDMMC CMD/DATx lines and set output
speed to medium. Using HIGH and VERYHIGH speeds seems
to cause data corruption, with frequent CRC failures.
Change-Id: I732d19e03a2a857453755b68b6749497eafaef70
The Echo R1 is a new open-hardware music player design, based
on the STM32H743 microcontroller. Schematics and hardware
documentation for it can be found here:
- https://github.com/amachronic/echoplayer
This is an incomplete port. The bootloader can be loaded using
OpenOCD and it can draw to the LCD using SPI. SDRAM is working
but hasn't been extensively tested.
Change-Id: Ifd2bee15c49868fbc989683d3ca14dce48bf3e18
