Hi Bin,
On 3 June 2015 at 06:59, Andrew Bradford <and...@bradfordembedded.com> wrote:
> On 06/03 07:17, Bin Meng wrote:
>> Hi Andrew,
>>
>> On Wed, Jun 3, 2015 at 4:05 AM, Andrew Bradford
>> <and...@bradfordembedded.com> wrote:
>> > Hi Bin,
>> >
>> > On 06/01 20:31, Bin Meng wrote:
>> >> The call to FspInitEntry is done in arch/x86/lib/fsp/fsp_car.S so far.
>> >> It worked pretty well but looks not that good. Apart from doing too
>> >> much work than just enabling CAR, it cannot read the configuration
>> >> data from device tree at that time. Now we want to move it a little
>> >> bit later as part of init_sequence_f[] being called by board_init_f().
>> >> This way it looks and works better in the U-Boot initialization path.
>> >>
>> >> Due to FSP's design, after calling FspInitEntry it will not return to
>> >> its caller, instead it jumps to a continuation function which is given
>> >> by bootloader with a new stack in system memory. The original stack in
>> >> the CAR is gone, but its content is perserved by FSP and described by
>> >> a bootloader temporary memory HOB. Technically we can recover anything
>> >> we had before in the previous stack, but that is way too complicated.
>> >> To make life much easier, in the FSP continuation routine we just
>> >> simply call fsp_init_done() and jump back to car_init_ret() to redo
>> >> the whole board_init_f() initialization, but this time with a non-zero
>> >> HOB list pointer saved in U-Boot's global data so that we can bypass
>> >> the FspInitEntry for the second time.
>> >>
>> >> Signed-off-by: Bin Meng <bmeng...@gmail.com>
>> >>
>> >> ---
>> >>
>> >> arch/x86/cpu/start.S | 6 +++++-
>> >> arch/x86/include/asm/u-boot-x86.h | 4 ++++
>> >> arch/x86/lib/fsp/fsp_car.S | 26 +++++---------------------
>> >> arch/x86/lib/fsp/fsp_common.c | 8 ++++++++
>> >> common/board_f.c | 3 +++
>> >> 5 files changed, 25 insertions(+), 22 deletions(-)
>> >>
>> >> diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S
>> >> index 2e5f9da..00e585e 100644
>> >> --- a/arch/x86/cpu/start.S
>> >> +++ b/arch/x86/cpu/start.S
>> >> @@ -116,12 +116,16 @@ car_init_ret:
>> >> rep stosb
>> >>
>> >> #ifdef CONFIG_HAVE_FSP
>> >> + test %esi, %esi
>> >> + jz skip_hob
>> >> +
>> >> /* Store HOB list */
>> >> movl %esp, %edx
>> >> addl $GD_HOB_LIST, %edx
>> >> movl %esi, (%edx)
>> >> -#endif
>> >>
>> >> +skip_hob:
>> >> +#endif
>> >> /* Setup first parameter to setup_gdt, pointer to global_data */
>> >> movl %esp, %eax
>> >>
>> >> diff --git a/arch/x86/include/asm/u-boot-x86.h
>> >> b/arch/x86/include/asm/u-boot-x86.h
>> >> index faa5182..9ee4104 100644
>> >> --- a/arch/x86/include/asm/u-boot-x86.h
>> >> +++ b/arch/x86/include/asm/u-boot-x86.h
>> >> @@ -54,6 +54,10 @@ u32 isa_map_rom(u32 bus_addr, int size);
>> >> /* arch/x86/lib/... */
>> >> int video_bios_init(void);
>> >>
>> >> +#ifdef CONFIG_HAVE_FSP
>> >> +int x86_fsp_init(void);
>> >> +#endif
>> >> +
>> >> void board_init_f_r_trampoline(ulong) __attribute__ ((noreturn));
>> >> void board_init_f_r(void) __attribute__ ((noreturn));
>> >>
>> >> diff --git a/arch/x86/lib/fsp/fsp_car.S b/arch/x86/lib/fsp/fsp_car.S
>> >> index 5e09568..afbf3f9 100644
>> >> --- a/arch/x86/lib/fsp/fsp_car.S
>> >> +++ b/arch/x86/lib/fsp/fsp_car.S
>> >> @@ -56,28 +56,10 @@ temp_ram_init_ret:
>> >>
>> >> /* stack grows down from top of CAR */
>> >> movl %edx, %esp
>> >> + subl $4, %esp
>> >>
>> >> - /*
>> >> - * TODO:
>> >> - *
>> >> - * According to FSP architecture spec, the fsp_init() will not
>> >> return
>> >> - * to its caller, instead it requires the bootloader to provide a
>> >> - * so-called continuation function to pass into the FSP as a
>> >> parameter
>> >> - * of fsp_init, and fsp_init() will call that continuation function
>> >> - * directly.
>> >> - *
>> >> - * The call to fsp_init() may need to be moved out of the car_init()
>> >> - * to cpu_init_f() with the help of some inline assembly codes.
>> >> - * Note there is another issue that fsp_init() will setup another
>> >> stack
>> >> - * using the fsp_init parameter stack_top after DRAM is initialized,
>> >> - * which means any data on the previous stack (on the CAR) gets lost
>> >> - * (ie: U-Boot global_data). FSP is supposed to support such
>> >> scenario,
>> >> - * however it does not work. This should be revisited in the future.
>> >> - */
>> >> - movl $CONFIG_FSP_TEMP_RAM_ADDR, %eax
>> >> - xorl %edx, %edx
>> >> - xorl %ecx, %ecx
>> >> - call fsp_init
>> >> + xor %esi, %esi
>> >> + jmp car_init_done
>> >>
>> >> .global fsp_init_done
>> >> fsp_init_done:
>> >> @@ -86,6 +68,8 @@ fsp_init_done:
>> >> * Save eax to esi temporarily.
>> >> */
>> >> movl %eax, %esi
>> >> +
>> >> +car_init_done:
>> >> /*
>> >> * Re-initialize the ebp (BIST) to zero, as we already reach here
>> >> * which means we passed BIST testing before.
>> >> diff --git a/arch/x86/lib/fsp/fsp_common.c b/arch/x86/lib/fsp/fsp_common.c
>> >> index 001494d..5b25632 100644
>> >> --- a/arch/x86/lib/fsp/fsp_common.c
>> >> +++ b/arch/x86/lib/fsp/fsp_common.c
>> >> @@ -46,3 +46,11 @@ void board_final_cleanup(void)
>> >>
>> >> return;
>> >> }
>> >> +
>> >> +int x86_fsp_init(void)
>> >> +{
>> >> + if (!gd->arch.hob_list)
>> >> + fsp_init(CONFIG_FSP_TEMP_RAM_ADDR, BOOT_FULL_CONFIG, NULL);
>> >> +
>> >> + return 0;
>> >> +}
>> >> diff --git a/common/board_f.c b/common/board_f.c
>> >> index fbbad1b..21be26f 100644
>> >> --- a/common/board_f.c
>> >> +++ b/common/board_f.c
>> >> @@ -753,6 +753,9 @@ static init_fnc_t init_sequence_f[] = {
>> >> #ifdef CONFIG_OF_CONTROL
>> >> fdtdec_setup,
>> >> #endif
>> >> +#if defined(CONFIG_X86) && defined(CONFIG_HAVE_FSP)
>> >> + x86_fsp_init,
>> >> +#endif
>> >> #ifdef CONFIG_TRACE
>> >> trace_early_init,
>> >> #endif
>> >
>> > Overall, I like the idea of these two patches!
>> >
>> > In my quick testing on my Valley Island, I now appear to have access to
>> > the gd and device tree blob prior to calling the fsp to setup SDRAM.
>>
>> Yes, that's expected. Besides the device tree access, are you able to
>> boot the Valley Island successfully with these two patches?
>
> Yes! :)
>
> I'm able to boot and to extract data from the device tree prior to
> calling into the FSP. So with a patchset like this one that you've
> proposed I could then implement moving the fsp_config vpd data into
> device tree to much more easily support additional baytrail boards.
>
> Tested-by: Andrew Bradford <andrew.bradf...@kodakalaris.com>
>
> Thanks!
> -Andrew
This is a big step forward - congrats on getting this running!
I feel that ultimately the FSP init fits better in dram_init(), but by
that time we have emitted serial output and the 'second pass' logic
gets a lot more messy. So let's go with what you have for now.
Acked-by: Simon Glass <s...@chromium.org>
Regards,
Simon
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