[PATCH v1 0/4] k3: migrate SPL_TEXT_BASE to new address

[Nishanth Menon]

On 19:18-20250416, Anshul Dalal wrote:
> On Wed Apr 16, 2025 at 4:54 PM IST, Nishanth Menon wrote:
> > On 13:00-20250416, Anshul Dalal wrote:
> >> The change to ATF's PRELOADED_BL33_BASE[1] requires respective changes to
> >> SPL_TEXT_BASE on u-boot side. This is necessary to allow the ATF to jump
> >> directly to linux kernel (like in falcon mode) which requires a 2MiB aligned
> >> load address[2]. The current address ATF jumps to is 0x80080000 which is not
> >> 2MiB aligned.
> >> 
> >> Therefore in parallel to the ATF change, this patch set makes the corresponding
> >> changes to u-boot. To maintain backwards compatibility with older ATF builds
> >> (that still use older address of 0x80080000), the patch set also adds a
> >> jump-stub which modifies the execution as follows:
> >> 
> >> Old ATF -> 0x80080000 -> 0x822000000 (Main domain SPL or kernel image)
> >>            jump stub    SPL_TEXT_BASE
> >> 
> >> With the following instructions loaded by the jump-stub:
> >> ADDR       | Instruction
> >> 0x80080000 |   mov x15, CONFIG_SPL_TEXT_BASE (0x822000000)
> >> 0x80080004 |   br x15
> >> 
> >> Depends on:
> >>  * [PATCH v3] configs: set SPL_TEXT_BASE by default for k3 platforms
> >>    https://lore.kernel.org/u-boot/20250415095028.446254-1-anshuld@ti.com/
> >> 
> >> [1]:
> >> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/37447
> >> [2]:
> >> "The Image must be placed text_offset bytes from a 2MB aligned base
> >> address anywhere in usable system RAM and called there."
> >> - Documentation/arch/arm64/booting.rst (linux kernel)
> >> 
> >> Anshul Dalal (4):
> >>   spl: Kconfig: k3: set SPL_TEXT_BASE to 0x82200000
> >>   mach-k3: add a jump stub to support older ATF builds
> >>   binman: k3: add jump-stub to tispl.bin
> >>   binman: k3: add jump-stub as loadable
> >
> >
> > 	How about u-boot documentation?
> 
> I will update that in the next revision along with any feedback I
> receive on this patch.

IMHO, This change is too intrusive and impacts downstream customers
including inflight production devices.

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D