On Sat, Jan 18, 2020 at 10:09 AM Philippe Mathieu-Daudé <
address@hidden> wrote:
On 1/15/20 12:10 AM, Niek Linnenbank wrote:
> On Tue, Jan 14, 2020 at 12:28 AM Philippe Mathieu-Daudé
> <address@hidden <mailto:address@hidden>> wrote:
>
> On 1/8/20 9:00 PM, Niek Linnenbank wrote:
> > A real Allwinner H3 SoC contains a Boot ROM which is the
> > first code that runs right after the SoC is powered on.
> > The Boot ROM is responsible for loading user code (e.g. a bootloader)
> > from any of the supported external devices and writing the downloaded
> > code to internal SRAM. After loading the SoC begins executing the
> code
> > written to SRAM. This commits adds emulation of the Boot ROM firmware
> > setup functionality by loading user code from SD card.
> >
> > Signed-off-by: Niek Linnenbank <address@hidden
> <mailto:address@hidden>>
> > ---
> > include/hw/arm/allwinner-h3.h | 23 +++++++++++++++++++++++
> > hw/arm/allwinner-h3.c | 28 ++++++++++++++++++++++++++++
> > hw/arm/orangepi.c | 3 +++
> > 3 files changed, 54 insertions(+)
> >
> > diff --git a/include/hw/arm/allwinner-h3.h
> b/include/hw/arm/allwinner-h3.h
> > index 5d74cca28e..4b66227ac4 100644
> > --- a/include/hw/arm/allwinner-h3.h
> > +++ b/include/hw/arm/allwinner-h3.h
> > @@ -50,6 +50,7 @@
> > #include "hw/sd/allwinner-sdhost.h"
> > #include "hw/net/allwinner-sun8i-emac.h"
> > #include "target/arm/cpu.h"
> > +#include "sysemu/block-backend.h"
> >
> > /**
> > * Allwinner H3 device list
> > @@ -130,4 +131,26 @@ typedef struct AwH3State {
> > MemoryRegion sram_c;
> > } AwH3State;
> >
> > +/**
> > + * Emulate Boot ROM firmware setup functionality.
> > + *
> > + * A real Allwinner H3 SoC contains a Boot ROM
> > + * which is the first code that runs right after
> > + * the SoC is powered on. The Boot ROM is responsible
> > + * for loading user code (e.g. a bootloader) from any
> > + * of the supported external devices and writing the
> > + * downloaded code to internal SRAM. After loading the SoC
> > + * begins executing the code written to SRAM.
> > + *
> > + * This function emulates the Boot ROM by copying 32 KiB
> > + * of data from the given block device and writes it to
> > + * the start of the first internal SRAM memory.
> > + *
> > + * @s: Allwinner H3 state object pointer
> > + * @blk: Block backend device object pointer
> > + * @errp: Error object pointer for raising errors
> > + */
> > +void allwinner_h3_bootrom_setup(AwH3State *s, BlockBackend *blk,
> > + Error **errp);
> > +
> > #endif /* HW_ARM_ALLWINNER_H3_H */
> > diff --git a/hw/arm/allwinner-h3.c b/hw/arm/allwinner-h3.c
> > index e692432b4e..e7b768ad5b 100644
> > --- a/hw/arm/allwinner-h3.c
> > +++ b/hw/arm/allwinner-h3.c
> > @@ -27,6 +27,7 @@
> > #include "hw/char/serial.h"
> > #include "hw/misc/unimp.h"
> > #include "hw/usb/hcd-ehci.h"
> > +#include "hw/loader.h"
> > #include "sysemu/sysemu.h"
> > #include "hw/arm/allwinner-h3.h"
> >
> > @@ -168,6 +169,33 @@ enum {
> > AW_H3_GIC_NUM_SPI = 128
> > };
> >
> > +void allwinner_h3_bootrom_setup(AwH3State *s, BlockBackend *blk,
> Error **errp)
> > +{
> > + uint8_t *buffer;
> > + int64_t rom_size = 32 * KiB;
>
> Why restrict to 32K? The A1 SRAM is 64K.
>
>
> The reason is that the actual Boot ROM on the H3 also uses 32K:
> https://linux-sunxi.org/BROM
>
> See the 'U-Boot SPL Limitations' table at the end of the page.
>
> You can see the comment in the table there regarding the 32 KiB:
> "Sizes larger than 32 KiB are rejected by the BROM. Exactly 32 KiB is
> fine, as verified by writing a special pattern at the end of the SPL and
> checking it in the SRAM."
> Probably it would not harm to increase it to the full size of the SRAM,
> but I tried to model
> the behavior as close to the real hardware as possible.
OK, then please document this difference in the commit description -
such "While the A1 SRAM is 64K, we limit to 32K because ..." - and add a
reference to https://linux-sunxi.org/BROM#U-Boot_SPL_limitations
Agreed, I'll add this to the commit message.