First post, by 286developer
Hi! I'm trying to run a ROM file in Dosbox bypassing the shell.
The program was part of an old embedded system I have to emulate. It runs ok in real mode but there is a problem when switching to protected mode. It prepares correctly the memory to start running tasks but when it tries to jump to the first task, it fails.
I've been debuging the code and I've found the CPU_JMP method in the cpu.cpp file. There is a switch to test the descriptor type. The type read is 0x01 (DESC_286_TSS_A), but there is no branch for this kind of descriptor so it exits with the "JMP Illegal descriptor type" message.
Is this a missing feature in Dosbox? Which modifications should be made to make it run? How do the programs made for 80286 can run in Dosbox?
Thanks for your time