Hi,
On Oct 22, 2015 7:22 PM, "hl" hl@rock-chips.com wrote:
Hi Simon,
On 23/10/15 09:04, Simon Glass wrote:
Hi Eddie,
On 22 October 2015 at 18:54, Eddie Cai eddie.cai@rock-chips.com wrote:
Hi Simon
2015-10-23 0:30 GMT+08:00 Simon Glass sjg@chromium.org:
Hi Eddie,
On 22 October 2015 at 10:01, Eddie Cai eddie.cai@rock-chips.com
wrote:
Hi Simon
2015-10-22 22:07 GMT+08:00 Simon Glass sjg@chromium.org:
Hi Lin,
On 20 October 2015 at 20:37, Lin Huang hl@rock-chips.com wrote: > > it may not use SPL in other rockchip SOC, so move SUPPORT_SPL and > SPL config to rk3288 configuration. > > Signed-off-by: Lin Huang hl@rock-chips.com > --- > Changes in v1: None > > arch/arm/Kconfig | 2 -- > arch/arm/mach-rockchip/Kconfig | 2 ++ > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 194fb7b..40fa741 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -831,8 +831,6 @@ config TARGET_STM32F429_DISCOVERY > > config ARCH_ROCKCHIP > bool "Support Rockchip SoCs" > - select SUPPORT_SPL > - select SPL > select OF_CONTROL > select CPU_V7 > select DM > diff --git a/arch/arm/mach-rockchip/Kconfig > b/arch/arm/mach-rockchip/Kconfig > index ab50f4e..15cd380 100644 > --- a/arch/arm/mach-rockchip/Kconfig > +++ b/arch/arm/mach-rockchip/Kconfig > @@ -2,6 +2,8 @@ if ARCH_ROCKCHIP > > config ROCKCHIP_RK3288 > bool "Support Rockchip RK3288" > + select SUPPORT_SPL > + select SPL > help > The Rockchip RK3288 is a ARM-based SoC with a quad-core > Cortex-A17 > including NEON and GPU, 1MB L2 cache, Mali-T7 graphics,
two
> -- > 1.9.1 > We should avoid little binary blobs for booting the chip. I think we can live with this as a stepping stone to having a proper SPL, but what is the plan for a proper SPL in U-Boot?
RK3036 have only 8k sram. 4k used by boot rom. The ddr initialize code is almost 4k. So i don't think we can do SPL.
How does U-Boot get loaded in this case? Does it use ROM code? If so
Yes, it use boot rom code to load U-Boot
then I think we should create an SPL that handles the DDR init and then returns to the ROM code for loading U-Boot. Also we should document how this works in the README.
It is a good news you agree we can return to boot rom from SPL. Do you
know
what size of sram a smallest SPL need?
Exynos does something a little similar - it has a jump table of ROM routines that SPL can call.
You can essentially write your own code for SPL. I very much hope you can use start.S and cro0.S, but these add up to a tiny amount of code so should not cause problems. You should be able to put all of your code into your implementation of board_init_f(), using most of the 4KB available. U-Boot's SPL framework does add some overhead, but if you leave out the board_init_r() implementation this is very small.
If you do get stuck and find the size if over 4KB we should discuss it and see what can be done.
Okay, i will reference exynos to see how to do, thank you.
One last point... U-Boot is written in C so as much as possible of this should be C, rather than assembler.
Regards, Simon