i am working on a serial bootloader for which i dont have the original source code but i can debug it in Codewarrior with USBBDM.
The problem is when it reaches a certain point in the code. In sort it loads 0xF at GPAGE and then it stores a word or byte at the specified location.
On the GSTD or GSTAB instruction the cpu resets. So i have to start from the beginning. Here is the code in assemble language.
ORCC #0X10 LDAB 0x10 PSHB MOVB #0xF, 0x0010 LDX 0x300E LDD 0x3010 GSTD 0x0, X PULB STAB 0x10 ANDCC #0xEF RTS
The cpu resets at the GSTD instruction.
A sort explanation on what the above code does is this,
Store 0xF to GPAGE
Load target address in X and word in D
Save word D at 0xF_xxxx.
Can someone suggest something or have an idea on what is going wrong here?
I would expect that the 0xF_3000 is the "global" ram location which is the same as the "logical" ram location which is at 0x3000.