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? > + > 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? > #ifdef CONFIG_TRACE > trace_early_init, > #endif > -- > 1.8.2.1 > Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot