Hi, On 13 May 2015 at 20:02, Simon Glass <s...@chromium.org> wrote: > Hi, > > On 13 May 2015 at 16:40, Tim Harvey <thar...@gateworks.com> wrote: >> On Wed, May 13, 2015 at 12:58 PM, Tim Harvey <thar...@gateworks.com> wrote: >>> On Tue, May 12, 2015 at 8:14 AM, Tom Rini <tr...@konsulko.com> wrote: >>>> On Mon, May 11, 2015 at 12:08:25PM -0700, Tim Harvey wrote: >>>>> On Fri, May 8, 2015 at 4:14 PM, Tom Rini <tr...@konsulko.com> wrote: >>>>> > On Sat, May 09, 2015 at 12:15:37AM +0200, Marek Vasut wrote: >>>>> >> On Friday, May 08, 2015 at 11:51:36 PM, Tim Harvey wrote: >>>>> >> > Allocating space for temporary env on the stack makes >>>>> >> > env_relocate_spec() >>>>> >> > unsuitable for SPL environments which have very little stack. >>>>> >> >>>>> >> Well yeah, but what if you don't have malloc area ? I'd expect that >>>>> >> the be the case in SPL quite often. >>>>> > >>>>> > OK, hold up. We went through this a while back which is why things are >>>>> > how they are today. First, we have things setup today such that you can >>>>> > throw stack (at the point we do env in SPL) into DDR. This means we can >>>>> > keep doing things the way they are. You can take a look at >>>>> > include/configs/am335x_evm.h and where CONFIG_EMMC_BOOT is set, that's >>>>> > how we do what it looks like you're trying to do on imx6 but on TI >>>>> > am335x. >>>>> >>>>> Yes, I'm doing this on Gateworks Ventana (board/gateworks/gw_ventana) >>>>> based on IMX6 which has a limmited stack size during SPL. I don't see >>>>> anything magic in include/configs/am335x_evm.h that catches my >>>>> attention. Do you know where the code is that lets you point the stack >>>>> to DDR? It sounds like that's what I need. >>>> >>>> Ah oops. Kconfig, we use Kconfig now :) >>>> configs/am335x_evm_defconfig:CONFIG_SPL_STACK_R=y >>>> configs/am335x_evm_defconfig:CONFIG_SPL_STACK_R_ADDR=0x82000000 >>>> >>>> That's moving stack to DDR and then grabbing 0x82000000 for stack (base >>>> + 0x02000000 which is not too high, not too low, not likely to stomp on >>>> the kernel). >>> >>> thats strange... common/spl/spl.c uses CONFIG_SPL_STACK_R as the >>> address not CONFIG_SPL_STACK_R_ADDR - how can that even compile? >>> >>> http://git.denx.de/?p=u-boot.git;a=blob;f=common/spl/spl.c;#l324 >> >> Tom, >> >> I don't really understand the CONFIG_SPL_STACK_R usage at all. The >> only thing that uses CONFIG_SPL_STACK_R is spl_relocate_stack_gd which >> is called from arch/arm/lib/crt0.S 'after' board_init_f() is called, >> which will never return for SPL because we loaded and jumped to >> u-boot.img. >> >> How is this working for the am335x stuff? > > Tom just forwarded me this thread. There is definitely something > missing upstream compared to my local branch. I'll take a look and see > what I missed.
It should say CONFIG_SPL_STACK_R_ADDR instead of CONFIG_SPL_STACK_R As to the question about why CONFIG_SPL_STACK_R does not produce a compile error, it is defined to 1 in autoconf.h, which is a valid number. With the current value it sets the stack to 0xffffff28 which seems invalid to me (it is in reserved memory). It's a little bit of a mystery as to why this works on my beaglebone black. Anyway I have sent a patch to correct it. There are instructions in the README for using CONFIG_SPL_STACK_R, and for the new board init flow. Basically you need to return normally from your SPL board_init_f(). The code in crt0.S will then change the SPL stack to CONFIG_SPL_STACK_R_ADDR which should be in SDRAM and everything should be good. So perhaps what you are missing is that board_init_f() is now expected to return. It must not load U-Boot at this stage. That is supposed to happen in board_init_r(). Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
