On 16 December 2013 23:40, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote:
> On Thu, Nov 28, 2013 at 01:33:21PM +0000, Peter Maydell wrote:
>> From: "Mian M. Hamayun" <m.hamayun@xxxxxxxxxxxxxxxxxxxxxx>
>>
>> This commit adds support for booting a single AArch64 CPU by setting
>> appropriate registers. The bootloader includes placehoders for Board-ID
>> that are used to implement uniform indexing across different bootloaders.
>>
>> Signed-off-by: Mian M. Hamayun <m.hamayun@xxxxxxxxxxxxxxxxxxxxxx>
>> [PMM:
>> * updated to use ARMInsnFixup style bootloader fragments
>> * dropped virt.c additions
>> * use runtime checks for "is this an AArch64 core" rather than ifdefs
>> * drop some unnecessary setting of registers in reset hook
>> ]
>> Signed-off-by: Peter Maydell <peter.maydell@xxxxxxxxxx>
>> ---
>> hw/arm/boot.c | 40 +++++++++++++++++++++++++++++++++++-----
>> 1 file changed, 35 insertions(+), 5 deletions(-)
>>
>> diff --git a/hw/arm/boot.c b/hw/arm/boot.c
>> index 77d29a8..b6b04b7 100644
>> --- a/hw/arm/boot.c
>> +++ b/hw/arm/boot.c
>> @@ -19,6 +19,8 @@
>>
>> #define KERNEL_ARGS_ADDR 0x100
>> #define KERNEL_LOAD_ADDR 0x00010000
>> +/* The AArch64 kernel boot protocol specifies a different preferred address */
>> +#define KERNEL64_LOAD_ADDR 0x00080000
>
> I assume you referring to Documentation/arm/Booting and
> Documentation/arm64/booting.txt here? Perhaps it would be nicer to
> refer to that and state how we reach the address for the two archs
> instead of having the aarch64 specific note here, e.g. "The kernel
> recommends booting at offset 0x80000 from system RAM" or something like
> that...
Yeah, we could put the references to the document names in.
I don't see the point repeating the 0x80000 figure in the comment though.
>>
>> typedef enum {
>> FIXUP_NONE = 0, /* do nothing */
>> @@ -37,6 +39,20 @@ typedef struct ARMInsnFixup {
>> FixupType fixup;
>> } ARMInsnFixup;
>>
>> +static const ARMInsnFixup bootloader_aarch64[] = {
>> + { 0x580000c0 }, /* ldr x0, 18 ; Load the lower 32-bits of DTB */
>
> so by 18 you mean the label 0x18 assuming the instruction above has the
> label 0 or something like that? Is this an accepted/familiar notation
> or shoudl we do something like the arm32 bootloaders and "define a
> label in the comments"...?
referring down to a label or something would be better. This is probably
just a copy of output from a disassembler of a binary blob with assumed
offset zero.
thanks
-- PMM
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