> We are using Freescale i.Mx31 which is an ARM11 chip. > The problem happens when a 2-byte aligned address is assigned to > pointer which requires 4-byte aligned. For example, in lan92xx_send() > in if_lan92xx.c, one code line is as below, > ---------- > unsigned int data, *pdata; > pdata = (unsigned int *)sg_list[i].buf; > ----------- > Here sg_list[i].buf is 2-byte aligned while pdata needs 4-byte aligned. > Then following code will hang the system > ---------- > data = *pdata; > --------- > In fconfig.c, the problem is similar. Val_ptr is of "void *" type and > it is pointed to a char in a long string (for command processing). It > is not guaranteed to be 4-byte aligned. Then when setting IP address, > following code will fail > ---------- > lp += diag_sprintf(lp, "%s", inet_ntoa((in_addr_t *)val_ptr)); > --------- > Because (in_addr_t *) in function inet_ntoa expects val_ptr to be 4- > byte aligned. > > Do you think there is a way to work around this issue without code > modification?
Hi Karl, The ARM11 requires 32 bit accesses to be word aligned unless you have CP15 c1 set to allow unaligned access. I am suspicious that this is what may be happening based off of what you're saying. See chapter 4 of http://infocenter.arm.com/help/topic/com.arm.doc.ddi0211j/DDI0211J_arm1136_r1 p5_trm.pdf --Chris
