[U-Boot] [PATCH 09/10] x86: Access the VGA ROM when needed

[Simon Glass]

Hi Bin,

On 5 January 2015 at 06:49, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Mon, Jan 5, 2015 at 9:45 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Bin,
>>
>> On 3 January 2015 at 22:54, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Hi Simon,
>>>
>>> On Tue, Dec 30, 2014 at 10:32 AM, Simon Glass <sjg at chromium.org> wrote:
>>>> Add code to the generic pci_rom file to access the VGA ROM in PCI space
>>>> when needed.
>>>>
>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>> ---
>>>>
>>>>  drivers/pci/pci_auto.c | 28 +++++++++++++++++++++++++++-
>>>>  drivers/pci/pci_rom.c  |  7 ++++++-
>>>>  include/pci.h          |  9 +++++++++
>>>>  3 files changed, 42 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/pci/pci_auto.c b/drivers/pci/pci_auto.c
>>>> index 44470fa..61bf6b4 100644
>>>> --- a/drivers/pci/pci_auto.c
>>>> +++ b/drivers/pci/pci_auto.c
>>>> @@ -11,7 +11,7 @@
>>>>   */
>>>>
>>>>  #include <common.h>
>>>> -
>>>> +#include <errno.h>
>>>>  #include <pci.h>
>>>>
>>>>  #undef DEBUG
>>>> @@ -191,6 +191,32 @@ void pciauto_setup_device(struct pci_controller *hose,
>>>>         pci_hose_write_config_byte(hose, dev, PCI_LATENCY_TIMER, 0x80);
>>>>  }
>>>>
>>>> +int pciauto_setup_rom(struct pci_controller *hose, pci_dev_t dev)
>>>> +{
>>>> +       pci_addr_t bar_value;
>>>> +       pci_size_t bar_size;
>>>> +       u32 bar_response;
>>>> +       u16 cmdstat = 0;
>>>> +
>>>> +       pci_hose_write_config_dword(hose, dev, PCI_ROM_ADDRESS, -2);
>
> I think it is better for people to understand if not writing -2.

What should we use instead?

>
>>>> +       pci_hose_read_config_dword(hose, dev, PCI_ROM_ADDRESS, &bar_response);
>>>> +       if (!bar_response)
>>>> +               return -ENOENT;
>>>> +
>>>> +       bar_size = -(bar_response & ~1);
>>>> +       DEBUGF("PCI Autoconfig: ROM, size=%#x, ", bar_size);
>>>> +       if (pciauto_region_allocate(hose->pci_mem, bar_size, &bar_value) == 0) {
>>>
>>> Should we assume pci roms are always mapped using the pci_mem region?
>>> If not, maybe we can add another parameter 'region_type' to
>>> pciauto_setup_rom()?
>>
>> I'm not sure - do you think we should support the cacheable area too?
>> Would that help?
>>
>
> I'm not sure either. I thought you might know more than me as so far I
> see pci rom is used for vga, ahci, pxe roms, and storage media for mac
> addresses on some ethernet cards. They all belong to pci_mem regions.
> Let's do it pci_mem and revisit it in the future if we see something
> different.

OK.

Regards,
Simon