Garmin eTREX 20 working as an eTREX 30

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Originally Posted by kunix [Only registered and activated users can see links. Click Here To Register...]

I've written a new disasm script. I think it's better than the previous one I posted in this topic. It works by treating all the 4-bytes aligned 4-byte integers as pointers and judging if each one points to a function. Also smart_disasm requires that the firmware entry point is named "fw_base".

Code:

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...........
static smart_disasm_check_func(ptr,min,max)
{
............................
        if((ptr % 2) == 1 && max - addr >= 2 && (Word(addr) & 0xFF00) == 0xB500)
        .............................

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I think that this row have to be changed as
if((ptr % 2) == 0 && ...........

and also
addr = Dword(p);

i think that return program code at address p, not the address in p, as seems used in script ...

(ptr % 2) == 1 checks if the least significant bit of the pointer is set (i.e. if the pointer points to a THUMB function).
addr = Dword(p) reads 4 bytes which are treated then as a pointer to an ARM or THUMB function.
So those two places work as I wanted, no mistakes here :)
There are other mistakes, however.
All integers are signed in IDA script, so for(p = (min + 3) & (~3); max >= p && max - p >= 4; p = p + 4) is going to end too early if (unsigned)max>=0x80000000 and (unsigned)min<0x80000000.

Hi,

Quote:

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Originally Posted by haute [Only registered and activated users can see links. Click Here To Register...]

Update to 4.10

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I'm trying to update eTrex20 with eTrex20_30_Webupdater__410_20to30_jnx_Patched but it stops on screen Software Loader Ready.

Version 3.80 works ok.

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Quote:

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Originally Posted by pelsta [Only registered and activated users can see links. Click Here To Register...]

Version 3.80 works ok.

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^^ This... ;)