Hi Tom,
On Mon, May 30, 2016 at 11:14 AM, Tom Rini trini@konsulko.com wrote:
On Mon, May 30, 2016 at 09:51:22AM -0700, Steve Rae wrote:
From: Andre Przywara andre.przywara@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.przywara@arm.com Signed-off-by: Steve Rae srae@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 3I 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....
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, itexpects a header area filled with magic values.This option will add some space at the beginning of the image tolet 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 ?!?!?!
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 - _startThen 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> ?
Thanks, Steve
#endif /* __BCM28155_AP_H */ diff --git a/include/configs/sun50i.h b/include/configs/sun50i.h index 0fdb4c7..fe9624b 100644 --- a/include/configs/sun50i.h +++ b/include/configs/sun50i.h @@ -17,6 +17,11 @@ #define GICD_BASE 0x1c81000 #define GICC_BASE 0x1c82000
+#ifdef CONFIG_SUNXI_BOOT0 +#define CONFIG_BOOT0_CODE \
.space 1532+#endif
and .../arch-sunxi/boot0.h
-- Tom