Hi Vichy,
To q1,
I think the memory contents should be (on Linux):
0 34
1 ef
2 cd
3 00
4 .
To q2,
If both of the i/o address and i/o value are ints, I think the final value
should be like these on Linux:
i/o value 0xdfef4523
i/o value 0x00000102
To q3,
The large value should be (on any system):
0x00AA36AB..F5
_____
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of vichy
Sent: Wednesday, January 23, 2008 3:48 PM
To: kernelnewbies@nl.linux.org
Subject: Question about Endian Order
Dear all:
While studying the kernel source code, I always confused with the Endian
Order.
I have studied the article about Endian order on the net.
Usually they gave an example as below:
A 4 byte LongInt
0xabcdefgh
will be arranged in memory as follows:
Base Address+0 gh
Base Address+1 ef
Base Address+2 cd
Base Address+3 ab
But what is the correct unit I should take to interpret the content of
memory?
I purposely use data not 4-bytes alignment in the following questions.
Question 1:
What does the memory arrangement look like as the value is 0xcdef34?
Will it be
Base Address+0 34
Base Address+1 ef
Base Address+2 cd
Question 2:
if the answer of Q1 is right and some document tells me that
offset 0 i/o address
offset 3 i/o value
and I got the memory content as
Base Address+0 23
Base Address+1 45
Base Address+2 ef
Base Address+3 df
Base Address+4 02
Base Address+5 01
Does that mean the i/o address is 0xef4523 and i/o value is 0x0102df?
Question 3:
If I got a big array which represents a large number like below:
static unsigned char n[] =
"\x00\xAA\x36\xAB\xCE\x88\xAC\xFD\xFF\x55\x52\x3C\x7F\xC4\x52\x3F"
"\x90\xEF\xA0\x0D\xF3\x77\x4A\x25\x9F\x2E\x62\xB4\xC5\xD9\x9C\xB5"
"\xAD\xB3\x00\xA0\x28\x5E\x53\x01\x93\x0E\x0C\x70\xFB\x68\x76\x93"
"\x9C\xE6\x16\xCE\x62\x4A\x11\xE0\x08\x6D\x34\x1E\xBC\xAC\xA0\xA1"
"\xF5";
Should the value be 0xF5A1A0ACBc ...., from 0xn[end] ~ n[0], just like
little-endian order, or 0x00AA36AB..F5, just like big-endian order.
Or this value will be different under different machine even it is a c
source code.
Appreciate your help,
vichy
