Hi Bin, On 5 June 2015 at 09:57, Bin Meng <bmeng...@gmail.com> wrote: > Hi Simon, > > On Fri, Jun 5, 2015 at 11:34 PM, Simon Glass <s...@chromium.org> wrote: >> On 4 June 2015 at 04:28, Bin Meng <bmeng...@gmail.com> 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> >>> Acked-by: Simon Glass <s...@chromium.org> >>> Tested-by: Andrew Bradford <andrew.bradf...@kodakalaris.com> >>> >> >> Tested on Minnowboard MAX: >> Tested-by: Simon Glass <s...@chromium.org> >> >>> --- >>> >>> Changes in v2: None >>> >>> 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 67c0098..5d8a96d 100644 >>> --- a/arch/x86/include/asm/u-boot-x86.h >>> +++ b/arch/x86/include/asm/u-boot-x86.h >>> @@ -52,6 +52,10 @@ 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 >> >> Can we drop the #ifdef here? > > Yes, in v3. > >>> + >>> 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 >> >> Would it be possible to put this into arch_cpu_init()? Or do you think >> it is better to have a separate call? >> > > I was thinking to do that in arch_cpu_init previously, but I changed > my idea mainly for: > - I need modify every cpu codes which uses FSP. So far there are two, > not a big deal :) > - Since x86_fsp_init() will jump back to call board_init_f() again, I > feel putting it as early as possible right after fdtdec_setup() could > save some boot time, like no need to execute trace_early_init() and > initf_malloc() which are meaningless, while still could gain access to > device tree.
OK, then let's leave it as it is. I have added a CPU uclass and perhaps we can try to remove some of the arch-specific init that way. E.g. we could have an fsp_init() method. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot