Linux on NCD/HMX
Network Computing Device's HMX model X-terminals use a 64-bit R4600 processor (rev. 1.7). Linux has not yet been ported. However there is a Linux on Explora project. The Explora model X-terms use a PowerPC processors. However the systems are very similar.
If you want to port Linux to the HMX, the following information will be useful :
The boot image is checksummed. To get past the CRC check, you must poke 0x20 at offset 0x1000f in Xncdhmx. For more details, see the PPC boot code in the Explora project.
The terminal will gently run any ELF executable, provided it's physical loading address is 0, virtual address is 0x40020000, and it has a header like this :
start: b .continue nop nop dc.w $20 ; this value is important ! dc.b "XncdHMX", 0 dc.w 0 dc.w 0 dc.w .return, 0 .return: jr r31 .continue: nop
At boot (640x480) the frame buffer is at 0x80000800 (8 bpp, black is 0xff, white is 0x00). The ROM is at 0xfc000000.
You can get the ROM here.