Reorganize the and optimize the code to avoid redundant code and thus
reduce code size, while making sure to zero-initialize the used areas
on the SD card. These are the "clean" part of this change.
The "dirty" part:
Optimize the FAT16 export code further by introducing small deviations
from the FAT16 specification. These deviations should not be harmful
at all, unless the SD card is used for something requiring the jump
instruction and/or boot code in the boot sector to be valid. This is
typically only required when booting off the filesystem.
After these changes, a considerable reduction in code size can be
observed for sys_controller.elf and sys_onchip_memory2_0.bin:
sys_controller.elf:
text data bss dec hex filename
32392 2936 2652 37980 945c sys_controller.elf
sys_onchip_memory2_0.bin:
size: 35328 bytes
This reduces the cost of the FAT16 export feature to 446 bytes.
The behavior of the menu option was all over the place, and would
easily leave the OSD in a weird state, requiring the user to blindly
do something that completely redraws the OSD.
Fix this by making the behavior similar to that of the userdata import
feature, with the difference of giving a more specific error message
when something goes wrong.
A very simple implementation, as we are very short on remaining
block RAM. Simply blindly copies the entire userdata area to the
SD card. This may subject the SD card to some extra wear, as well
as potentially read-disturb some Flash memory pages, but this would
require more code.
* replace all clock muxes with a single cycloneive_clkctrl to minimize skew
* use a single dynamically configured PLL to comply with cycloneive_clkctrl
* Disable 480p scanlines in auto mode
* Remove inoperable 3x/4x processing modes from 1080i list
* Add 640x512 mode to 480p group and limit 480p sampler option to 525-line modes
* Fix occasional pixel repetion issue after HDMI<->DVI TX switch
* Add "Allow upsample2x" option
* Add comments to some unclear sections
* workaround for phase shift issue on optimized modes
* add hscale option for 256x240 opt Line3x mode
* distribute video modes to groups and allow passthru for all modes
