[Xen-devel] C Macros and Xen RING Macros Questions

[Daniel Castro <evil.dani@xxxxxxxxx>]

hello All,

I am still working on the PV Drivers for SeaBIOS using upstream qemu.
And, I have two questions.
1.
Here is the location of all relevant data structs:
blkfront_info:0x000fd620 shared_ring:0x0009a000 private_ring:0x0009b000
DEBUG Read op private ring at 0x0009b000-0x000ab000, idx 63478
Here is my problem, when I do:
        ring_req =
GLOBALFLAT2GLOBAL(RING_GET_REQUEST(GET_GLOBALFLAT(bi->private),GLOBALFLAT2GLOBAL(GET_GLOBALFLAT(bi->private)->req_prod_pvt)));
 //please ignore the MACROS for now, or read further down.
I get:
After RING_GET_REQUEST operation ring request is at 0xe18ea40f id:0
But I have the feeling that the request should be between
0x0009b000-0x000ab000. Right?

2.
As you can see in the above code I use some SeaBIOS macros to access
32Bit addresses in 16Bit code. My second questions is: How the memory
access macros affect the RING macros? Do I need to rewrite the ring
macros to use the memory macros inside, for example:
/* How big is this ring? */
#define RING_SIZE(_r)                                                   \
    ((_r)->nr_ents)

Should be instead:
/* How big is this ring? */
#define RING_SIZE(_r)                                                   \
    (GET_GLOBAL((_r)->nr_ents))

SeaBIOS macros need to be around ALL memory accesses.

This is a short message for something that might be to complex to
explain briefly, so please ask any questions that you deem necessary
to understand. Right now, I am developing the first stage of boot when
the BIOS requests address 7c00 to get the Boot sector. Once I get this
working we should have a working prototype for PV-drivers in seabios.

Thank you all for your interest,

Daniel

-- 
+-=====---------------------------+
| +---------------------------------+ | This space intentionally blank
for notetaking.
| |   | Daniel Castro,                |
| |   | Consultant/Programmer.|
| |   | U Andes                         |
+-------------------------------------+

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel