REing an arm asm function...

sub_203A0A4.c

#if 0
sub_203A0A4:
LDR     R3, [R1,#4]
CMP     R3, #0
LDRNE   R2, [R1]
STRNE   R2, [R3]
LDR     R2, [R1]
CMP     R2, #0
LDREQ   R0, [R1,#4]
LDRNE   R1, [R1,#4]
STRNE   R1, [R2,#4]
BX      LR
#endif

// =>

int *sub_203A0A4(int *R0, int **R1) {
    if(R1[1])
        R1[1][0] = R1[0];

    if(R1[0])
        R1[0][1] = R1[1];
    else
        return R1[1];

    return R0;
}

// => (guessing...)

typedef struct list list;
struct list {
    list *prev;
    list *next;

    // void *data ?
};

// drop an element from a list
// returns the new start of the list
list *list_drop(list *start, list *el) {
    if(el->next)
        el->next->prev = el->prev;

    if(el->prev)
        el->prev->next = el->next;
    else
        return el->next;

    return start;
}

sub_203A0CC.c

#if 0
sub_203A0CC:
STR     R0, [R1,#4]
MOV     R2, #0
STR     R2, [R1]
CMP     R0, #0
STRNE   R1, [R0]
MOV     R0, R1
BX      LR
#endif

// => (see sub_203A0A4.c)

// add a new element in a list from the start
// returns the new start of the list
list *list_prepend(list *start, list *new) {
    new->next = start;
    new->prev = NULL;

    if(start)
        start->prev = new;

    return new;
}