Now we can modify the loader. I have a hardware sdhc controller (coded in verilog - I will publish it when it can run with the Propeller ) so the loader can boot directly from the sd
And here are further modifications (hub.v, hub_ram.v, ROM_$F000-$FFFF_Byte_n.spin)...
1. There is only Hub RAM (48KB) and the ROM is remapped to the RAM.
2. The ROM is only 4KB ($F000..$FFFF interpreter/booter/runner) and is loaded as 4 ROM Byte0..3 files.
Again it is tested. This takes a little more FPGA logic but permits you to use 44KB of Hub RAM (of the 48KB total memory).
Comments
These have been tested on my DE0-Nano
RR20140816d_Unscrambled_ROM.zip
Now we can modify the loader. I have a hardware sdhc controller (coded in verilog
1. There is only Hub RAM (48KB) and the ROM is remapped to the RAM.
2. The ROM is only 4KB ($F000..$FFFF interpreter/booter/runner) and is loaded as 4 ROM Byte0..3 files.
Again it is tested. This takes a little more FPGA logic but permits you to use 44KB of Hub RAM (of the 48KB total memory).
RR20140816g_ROM_$F000-$FFFF_BYTE_x.zip