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Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board
From: |
Laszlo Ersek |
Subject: |
Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board |
Date: |
Fri, 05 Dec 2014 19:53:58 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 |
On 12/05/14 19:42, Peter Maydell wrote:
> On 30 November 2014 at 16:59, Laszlo Ersek <address@hidden> wrote:
>> fw_cfg already supports exposure over MMIO (used in ppc/mac_newworld.c,
>> ppc/mac_oldworld.c, sparc/sun4m.c); we can easily add it to the "virt"
>> board.
>>
>> The mmio register block of fw_cfg is advertized in the device tree. As
>> base address we pick 0x09020000, which conforms to the comment preceding
>> "a15memmap": it falls in the miscellaneous device I/O range 128MB..256MB,
>> and it is aligned at 64KB. The DTB properties follow the documentation in
>> the Linux source file "Documentation/devicetree/bindings/arm/fw-cfg.txt".
>>
>> fw_cfg automatically exports a number of files to the guest; for example,
>> "bootorder" (see fw_cfg_machine_reset()).
>>
>> Signed-off-by: Laszlo Ersek <address@hidden>
>> ---
>>
>> Notes:
>> v2:
>> - use a single mmio region of size 0x1000
>> - set "compatible" property to "qemu,fw-cfg-mmio"
>>
>> hw/arm/virt.c | 21 +++++++++++++++++++++
>> 1 file changed, 21 insertions(+)
>>
>> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
>> index 314e55b..af794ea 100644
>> --- a/hw/arm/virt.c
>> +++ b/hw/arm/virt.c
>> @@ -68,6 +68,7 @@ enum {
>> VIRT_UART,
>> VIRT_MMIO,
>> VIRT_RTC,
>> + VIRT_FW_CFG,
>> };
>>
>> typedef struct MemMapEntry {
>> @@ -107,6 +108,7 @@ static const MemMapEntry a15memmap[] = {
>> [VIRT_GIC_CPU] = { 0x08010000, 0x00010000 },
>> [VIRT_UART] = { 0x09000000, 0x00001000 },
>> [VIRT_RTC] = { 0x09010000, 0x00001000 },
>> + [VIRT_FW_CFG] = { 0x09020000, 0x00001000 },
>
> Where does this 0x1000 size come from? It's not the size
> of the memory region the fw_cfg device exports, and it
> means we'll end up telling the f/w in the dtb that the
> accessible region is bigger than it really is.
This has been specifically requested in
http://thread.gmane.org/gmane.linux.drivers.devicetree/101173/focus=101176
See also the list of changes in
http://thread.gmane.org/gmane.linux.drivers.devicetree/101276/focus=101277
> Otherwise this patch looks good to me.
>
> -- PMM
>
Thanks
Laszlo
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Peter Maydell, 2014/12/05
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board,
Laszlo Ersek <=
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Laszlo Ersek, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Peter Maydell, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Peter Maydell, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Laszlo Ersek, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Laszlo Ersek, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Peter Maydell, 2014/12/08
- Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Laszlo Ersek, 2014/12/08
Re: [Qemu-devel] [PATCH v2] arm: add fw_cfg to "virt" board, Christopher Covington, 2014/12/08