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How can I install a list?

How can I install a list in a ARM controller?

typedef struct {
        volatile unsigned int *p_NextHdr;                       volatile unsigned int *p_PrevHdr;                       volatile unsigned int *p_data;
}*Hdr;

*p_NextHdr: ptr to the next list element
*p_PrevHdr: ptr to the previous list element
*p_data: ptr to the buffer (for this list element)

Hdr HdrPtr;

// ptr to the struct

At the beginning:

*p_NextHdr = *p_PrevHdr = *p_data = NULL;

But how can I install a few list elements? Could you tell me the next steps I have to do? How can I allocate storage for the struct?

best regards
Ingo

Parents

0 Ingo Schulz over 17 years ago in reply to Ingo Schulz

number of list elements with the struct data:

struct data *Header[NB_ETH_RX_PACKETS];

ptr to the tail and the start of the list

struct data *HdrEnd;
struct RxData *HdrBegin;

struct data

typedef struct data {
        volatile unsigned int Data;
        struct RxData *p_NextHdr;
        struct RxData *p_PrevHdr;
} *Hdr;

Hdr p_HdrLisPtr;

init pointers at the beginning:

HdrBegin->p_PrevHdr = HdrEnd->p_PrevHdr = HdrBegin;                  /* */
        HdrBegin->p_NextHdr = HdrEnd->p_NextHdr = HdrBufEnd;                  /* */
        p_HdrLisPtr = HdrBegin;

so now I should be able to install some list elements in a for-loop (for i=0; i<8; i++)

Header[i]->Data = i;


                // element in liste eintragen
                Header[i]->p_PrevHdr = p_HdrLisPtr;                                                          /* */
                Header[i]->p_NextHdr = p_HdrLisPtr->p_NextHdr;                                    /* */
                p_HdrLisPtr->p_NextHdr->p_PrevHdr = Header[i];                                    /* */
                p_HdrLisPtr->p_NextHdr = Header[i];

Are there any mistakes?

Ingo

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