On Mon, May 30, 2016 at 11:37:47AM -0700, Steve Rae wrote: > Hi Tom, > > On Mon, May 30, 2016 at 11:14 AM, Tom Rini <tr...@konsulko.com> wrote: > > > > On Mon, May 30, 2016 at 09:51:22AM -0700, Steve Rae wrote: > > > > > From: Andre Przywara <andre.przyw...@arm.com> > > > > > > Some SPL loaders (like Allwinner's boot0, and Broadcom's boot0) > > > require a header before the actual U-Boot binary to both check its > > > validity and to find other data to load. Sometimes this header may > > > only be a few bytes of information, and sometimes this might simply > > > be space that needs to be reserved for a post-processing tool. > > > > > > Introduce a config option to allow assembler preprocessor commands > > > to be inserted into the code at the appropriate location; typical > > > preprocessor commands might be: > > > .space 1000 > > > .word 0x12345678 > > > etc. > > > Please note that the current code: > > > start.S (arm64) and > > > vectors.S (arm) > > > already jumps over some portion of data already, so this option basically > > > just increases the size of this region (and the resulting binary). > > > > > > For use with Allwinner's boot0 blob there is a tool called boot0img[1], > > > which fills the header to allow booting A64 based boards. > > > For the Pine64 we need a 1536 byte header (including the branch > > > instruction) at the moment, so we add this to the defconfig. > > > > > > Signed-off-by: Andre Przywara <andre.przyw...@arm.com> > > > Signed-off-by: Steve Rae <s...@broadcom.com> > > > > I think this is a step in the right direction. > Thanks.... > > > > > [snip] > > > diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S > > > index e933021..9202889 100644 > > > --- a/arch/arm/cpu/armv8/start.S > > > +++ b/arch/arm/cpu/armv8/start.S > > > @@ -21,6 +21,10 @@ > > > _start: > > > b reset > > > > > > +#ifdef CONFIG_BOOT0_CODE > > > +CONFIG_BOOT0_CODE > > > +#endif > > > + > > > .align 3 > > > > I don't like adding things to the CONFIG name space that we can't > > control the contents of via Kconfig. So I think we need to change the > > BOOT0_CODE portion to something like ARMV8_SOC_BOOT0_HOOK. And if > > there's some part of the ARMv8 docs we can reference that explains why > > it's boot0 and at least 2 different SoCs have done this, we can use a > > better name here. > > > OK, I follow your logic -- but this is not ARMV8 specific... > In this commit: > - Allwinner is arm64, but > - Broadcom is arm (armv7l) > so maybe just: > SOC_BOOT0_HOOK ? > And I don't know where the "BOOT0" terminology started - maybe it is > in ARM/ARMV8 documentation; I just don't know....
OK. Yes, lets call it ARM_SOC_BOOT0_HOOK until/unless someone chimes in with a better still name. > > Then.. > > > diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig > > > index c1ae6f5..d2678c9 100644 > > > --- a/board/sunxi/Kconfig > > > +++ b/board/sunxi/Kconfig > > > @@ -15,6 +15,13 @@ config SUNXI_GEN_SUN6I > > > separate ahb reset control registers, custom pmic bus, new style > > > watchdog, etc. > > > > > > +config SUNXI_BOOT0 > > > + bool "prepare for boot0 header" > > > + ---help--- > > > + If U-Boot is loaded from the Allwinner provided boot0 blob, it > > > + expects a header area filled with magic values. > > > + This option will add some space at the beginning of the image to > > > + let a tool later on fill in this header with sensible data. > > > > This becomes something like ENABLE_ARMV8_SOC_BOOT0_HOOK and generic the > > text a bit more here and mention the Allwinner and Broadcom examples. > OK for the Allwinner... > But I don't think the Broadcom boards are going to define SUNXI_BOOT0 ?!?!?! Right. But it should become ENABLE_ARM_SOC_BOOT0_HOOK and both platforms (and other future ones probably) would enable it. > > > diff --git a/include/configs/bcm28155_ap.h b/include/configs/bcm28155_ap.h > > > index 889e5db..515552b 100644 > > > --- a/include/configs/bcm28155_ap.h > > > +++ b/include/configs/bcm28155_ap.h > > > @@ -137,4 +137,8 @@ > > > #define CONFIG_USB_GADGET_BCM_UDC_OTG_PHY > > > #define CONFIG_USBID_ADDR 0x34052c46 > > > > > > +#define CONFIG_BOOT0_CODE \ > > > + .word 0xbabeface; \ > > > + .word _end - _start > > > + > > > > Then this goes into arch/arm/include/asm/arch-bcm281xx/boot0.h or > > similar? > OK - I get that it shouldn't be in the (deprecated) include/configs > file(s).... > However, I didn't really want to add more #include lines to: > arch/arm/cpu/armv8/start.S or > arch/arm/lib/vectors.S > So, if I add your suggested filename, will it get "picked up" through > the existing > #include <config.h> > ? No, you would need to make both S files include <asm/arch/boot0.h> but I think that's a logical thing to do. I would be: #ifdef CONFIG_ENABLE_ARM_SOC_BOOT0_HOOK #include <asm/arch/boot0.h> /* * Various SoCs need something special and SoC-specific up front in * order to boot, allow them to set that in their boot0.h file and then * use it here. */ aRM_SOC_BOOT0_HOOK #endif -- Tom
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