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. >> #ifdef CONFIG_TRACE >> trace_early_init, >> #endif >> -- Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot