Re: [Freemint-discuss] Accessing Process Control Block (proc struct)

[Jo E. S. <jo...@on...>]

Ok, got it. This struct is protected and can not be accessed directly, you need to use Fread to access it.

Jo Even


On Thu, 10 Oct 2024 19:28:19 +0000, "Jo Even Skarstein" <jo...@on...> wrote:

>> From tos.hyp (Fcntl):
>>
>> > PPROCADDDR (0x5001):
>> >
>> > In the parameter arg a pointer to the address of the PCB (Process Control Block) is returned.
>>
>> The following code works and prints correct values (when compared with XaAES task manager and ps) when MP is disabled:
>>
>> void main(void)
>> {
>>     long f = Fopen("u:\\proc\\.11", 0); /* Same behaviour when opening .-1 too */
>>     struct PCB *p;
>>     printf("%ld\n", Fcntl((int) f, &p, 0x5001));
>>     printf("pid: %d systime: %ld usrtime: %ld\n", p->pid, p->systime, p->usrtime);
>> }
>>
>> However, if MP is enabled the same binary crashes with a bus error. Fcntl returns E_OK and the value of *p after the call looks sensible, but accessing the memory pointed to by *p results in a bus error. Am I doing something stupid here? I would assume so, since ps (the ancient one from MiNTOS/KGMD/SpareMiNT) works and I'm pretty sure it gets this information the same way.
>>
>> I have compiled it with both gcc and PureC with identical results.
>>
>> Jo Even
>>
>>
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