| Message ID | 1425394982-16196-5-git-send-email-sjg@chromium.org |
|---|---|
| State | Accepted |
| Delegated to: | Tom Rini |
| Headers | show |
On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > At present SPL uses a single stack, either CONFIG_SPL_STACK or > CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > point into SDRAM. They then set up SDRAM very early, before board_init_f(), > so that the larger stack can be used. > > This is an abuse of lowlevel_init(). That function should only be used for > essential start-up code which cannot be delayed. An example of a valid use is > when only part of the SPL code is visible/executable, and the SoC must be set > up so that board_init_f() can be reached. It should not be used for SDRAM > init, console init, etc. > > Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > address before board_init_r() is called in SPL. > > The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > > Signed-off-by: Simon Glass <sjg@chromium.org> > For version 1: > Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> > Reviewed-by: Stefan Roese <sr@denx.de> > Tested-by: Bo Shen <voice.shen@atmel.com> > Acked-by: Bo Shen <voice.shen@atmel.com> > Acked-by: Heiko Schocher <hs@denx.de> > Tested-by: Heiko Schocher <hs@denx.de> > --- > > Changes in v6: None > Changes in v5: > - Rebase to master > > Changes in v4: > - Adjust README to mention that lowlevel_init() should have no stack > > Changes in v3: None > Changes in v2: > - Move docs to top-level README file and expand them to cover U-Boot proper > - Add Kconfig settings > > Kconfig | 18 ++++++++++++++ > README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > arch/arm/lib/crt0.S | 13 +++++++--- > common/spl/spl.c | 35 +++++++++++++++++++++++++++ > 4 files changed, 132 insertions(+), 3 deletions(-) [snip] > diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S > index 22df3e5..7939ced 100644 > --- a/arch/arm/lib/crt0.S > +++ b/arch/arm/lib/crt0.S > @@ -113,7 +113,14 @@ here: > /* Set up final (full) environment */ > > bl c_runtime_cpu_setup /* we still call old routine here */ > - > +#endif > +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) > +# ifdef CONFIG_SPL_BUILD > + /* Use a DRAM stack for the rest of SPL, if requested */ > + bl spl_relocate_stack_gd > + cmp r0, #0 > + movne sp, r0 > +# endif > ldr r0, =__bss_start /* this is auto-relocated! */ > ldr r1, =__bss_end /* this is auto-relocated! */ > > @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > addlo r0, r0, #4 /* move to next */ > blo clbss_l > > +#if ! defined(CONFIG_SPL_BUILD) > bl coloured_LED_init > bl red_led_on > - > +#endif > /* call board_init_r(gd_t *id, ulong dest_addr) */ > mov r0, r9 /* gd_t */ > ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ > @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > ldr pc, =board_init_r /* this is auto-relocated! */ > > /* we should not return here. */ > - > #endif > > ENDPROC(_main) > diff --git a/common/spl/spl.c b/common/spl/spl.c > index ded0f30..cd75bbc 100644 > --- a/common/spl/spl.c > +++ b/common/spl/spl.c > @@ -281,3 +281,38 @@ void preloader_console_init(void) > spl_display_print(); > #endif > } > + > +/** > + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution > + * > + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM > + * for the main board_init_r() execution. This is typically because we need > + * more stack space for things like the MMC sub-system. > + * > + * This function calculates the stack position, copies the global_data into > + * place and returns the new stack position. The caller is responsible for > + * setting up the sp register. > + * > + * @return new stack location, or 0 to use the same stack > + */ > +ulong spl_relocate_stack_gd(void) > +{ > +#ifdef CONFIG_SPL_STACK_R > + gd_t *new_gd; > + ulong ptr; > + > + /* Get stack position: use 8-byte alignment for ABI compliance */ > + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); > + ptr &= ~7; > + new_gd = (gd_t *)ptr; > + memcpy(new_gd, (void *)gd, sizeof(gd_t)); > + gd = new_gd; > + > + /* Clear the BSS. */ > + memset(__bss_start, 0, __bss_end - __bss_start); > + > + return ptr; > +#else > + return 0; > +#endif > +} All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so the big use case (am335x_boneblack for example where CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow the area for stack.
Hi Tom, On 3 March 2015 at 10:49, Tom Rini <trini@konsulko.com> wrote: > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > >> At present SPL uses a single stack, either CONFIG_SPL_STACK or >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), >> so that the larger stack can be used. >> >> This is an abuse of lowlevel_init(). That function should only be used for >> essential start-up code which cannot be delayed. An example of a valid use is >> when only part of the SPL code is visible/executable, and the SoC must be set >> up so that board_init_f() can be reached. It should not be used for SDRAM >> init, console init, etc. >> >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new >> address before board_init_r() is called in SPL. >> >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. >> >> Signed-off-by: Simon Glass <sjg@chromium.org> >> For version 1: >> Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> >> Reviewed-by: Stefan Roese <sr@denx.de> >> Tested-by: Bo Shen <voice.shen@atmel.com> >> Acked-by: Bo Shen <voice.shen@atmel.com> >> Acked-by: Heiko Schocher <hs@denx.de> >> Tested-by: Heiko Schocher <hs@denx.de> >> --- >> >> Changes in v6: None >> Changes in v5: >> - Rebase to master >> >> Changes in v4: >> - Adjust README to mention that lowlevel_init() should have no stack >> >> Changes in v3: None >> Changes in v2: >> - Move docs to top-level README file and expand them to cover U-Boot proper >> - Add Kconfig settings >> >> Kconfig | 18 ++++++++++++++ >> README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ >> arch/arm/lib/crt0.S | 13 +++++++--- >> common/spl/spl.c | 35 +++++++++++++++++++++++++++ >> 4 files changed, 132 insertions(+), 3 deletions(-) > [snip] >> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S >> index 22df3e5..7939ced 100644 >> --- a/arch/arm/lib/crt0.S >> +++ b/arch/arm/lib/crt0.S >> @@ -113,7 +113,14 @@ here: >> /* Set up final (full) environment */ >> >> bl c_runtime_cpu_setup /* we still call old routine here */ >> - >> +#endif >> +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) >> +# ifdef CONFIG_SPL_BUILD >> + /* Use a DRAM stack for the rest of SPL, if requested */ >> + bl spl_relocate_stack_gd >> + cmp r0, #0 >> + movne sp, r0 >> +# endif >> ldr r0, =__bss_start /* this is auto-relocated! */ >> ldr r1, =__bss_end /* this is auto-relocated! */ >> >> @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ >> addlo r0, r0, #4 /* move to next */ >> blo clbss_l >> >> +#if ! defined(CONFIG_SPL_BUILD) >> bl coloured_LED_init >> bl red_led_on >> - >> +#endif >> /* call board_init_r(gd_t *id, ulong dest_addr) */ >> mov r0, r9 /* gd_t */ >> ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ >> @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ >> ldr pc, =board_init_r /* this is auto-relocated! */ >> >> /* we should not return here. */ >> - >> #endif >> >> ENDPROC(_main) >> diff --git a/common/spl/spl.c b/common/spl/spl.c >> index ded0f30..cd75bbc 100644 >> --- a/common/spl/spl.c >> +++ b/common/spl/spl.c >> @@ -281,3 +281,38 @@ void preloader_console_init(void) >> spl_display_print(); >> #endif >> } >> + >> +/** >> + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution >> + * >> + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM >> + * for the main board_init_r() execution. This is typically because we need >> + * more stack space for things like the MMC sub-system. >> + * >> + * This function calculates the stack position, copies the global_data into >> + * place and returns the new stack position. The caller is responsible for >> + * setting up the sp register. >> + * >> + * @return new stack location, or 0 to use the same stack >> + */ >> +ulong spl_relocate_stack_gd(void) >> +{ >> +#ifdef CONFIG_SPL_STACK_R >> + gd_t *new_gd; >> + ulong ptr; >> + >> + /* Get stack position: use 8-byte alignment for ABI compliance */ >> + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); >> + ptr &= ~7; >> + new_gd = (gd_t *)ptr; >> + memcpy(new_gd, (void *)gd, sizeof(gd_t)); >> + gd = new_gd; >> + >> + /* Clear the BSS. */ >> + memset(__bss_start, 0, __bss_end - __bss_start); >> + >> + return ptr; >> +#else >> + return 0; >> +#endif >> +} > > All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It > does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so > the big use case (am335x_boneblack for example where > CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow > the area for stack. OK I'll have to test more. What sort of problem should i see? The return value from spl_relocate_stack_gd() should be shoved into sp. Does that not happen? Regards, Simon
On Tue, Mar 03, 2015 at 12:04:16PM -0700, Simon Glass wrote: > Hi Tom, > > On 3 March 2015 at 10:49, Tom Rini <trini@konsulko.com> wrote: > > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > > > >> At present SPL uses a single stack, either CONFIG_SPL_STACK or > >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), > >> so that the larger stack can be used. > >> > >> This is an abuse of lowlevel_init(). That function should only be used for > >> essential start-up code which cannot be delayed. An example of a valid use is > >> when only part of the SPL code is visible/executable, and the SoC must be set > >> up so that board_init_f() can be reached. It should not be used for SDRAM > >> init, console init, etc. > >> > >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > >> address before board_init_r() is called in SPL. > >> > >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > >> > >> Signed-off-by: Simon Glass <sjg@chromium.org> > >> For version 1: > >> Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> > >> Reviewed-by: Stefan Roese <sr@denx.de> > >> Tested-by: Bo Shen <voice.shen@atmel.com> > >> Acked-by: Bo Shen <voice.shen@atmel.com> > >> Acked-by: Heiko Schocher <hs@denx.de> > >> Tested-by: Heiko Schocher <hs@denx.de> > >> --- > >> > >> Changes in v6: None > >> Changes in v5: > >> - Rebase to master > >> > >> Changes in v4: > >> - Adjust README to mention that lowlevel_init() should have no stack > >> > >> Changes in v3: None > >> Changes in v2: > >> - Move docs to top-level README file and expand them to cover U-Boot proper > >> - Add Kconfig settings > >> > >> Kconfig | 18 ++++++++++++++ > >> README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> arch/arm/lib/crt0.S | 13 +++++++--- > >> common/spl/spl.c | 35 +++++++++++++++++++++++++++ > >> 4 files changed, 132 insertions(+), 3 deletions(-) > > [snip] > >> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S > >> index 22df3e5..7939ced 100644 > >> --- a/arch/arm/lib/crt0.S > >> +++ b/arch/arm/lib/crt0.S > >> @@ -113,7 +113,14 @@ here: > >> /* Set up final (full) environment */ > >> > >> bl c_runtime_cpu_setup /* we still call old routine here */ > >> - > >> +#endif > >> +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) > >> +# ifdef CONFIG_SPL_BUILD > >> + /* Use a DRAM stack for the rest of SPL, if requested */ > >> + bl spl_relocate_stack_gd > >> + cmp r0, #0 > >> + movne sp, r0 > >> +# endif > >> ldr r0, =__bss_start /* this is auto-relocated! */ > >> ldr r1, =__bss_end /* this is auto-relocated! */ > >> > >> @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > >> addlo r0, r0, #4 /* move to next */ > >> blo clbss_l > >> > >> +#if ! defined(CONFIG_SPL_BUILD) > >> bl coloured_LED_init > >> bl red_led_on > >> - > >> +#endif > >> /* call board_init_r(gd_t *id, ulong dest_addr) */ > >> mov r0, r9 /* gd_t */ > >> ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ > >> @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > >> ldr pc, =board_init_r /* this is auto-relocated! */ > >> > >> /* we should not return here. */ > >> - > >> #endif > >> > >> ENDPROC(_main) > >> diff --git a/common/spl/spl.c b/common/spl/spl.c > >> index ded0f30..cd75bbc 100644 > >> --- a/common/spl/spl.c > >> +++ b/common/spl/spl.c > >> @@ -281,3 +281,38 @@ void preloader_console_init(void) > >> spl_display_print(); > >> #endif > >> } > >> + > >> +/** > >> + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution > >> + * > >> + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM > >> + * for the main board_init_r() execution. This is typically because we need > >> + * more stack space for things like the MMC sub-system. > >> + * > >> + * This function calculates the stack position, copies the global_data into > >> + * place and returns the new stack position. The caller is responsible for > >> + * setting up the sp register. > >> + * > >> + * @return new stack location, or 0 to use the same stack > >> + */ > >> +ulong spl_relocate_stack_gd(void) > >> +{ > >> +#ifdef CONFIG_SPL_STACK_R > >> + gd_t *new_gd; > >> + ulong ptr; > >> + > >> + /* Get stack position: use 8-byte alignment for ABI compliance */ > >> + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); > >> + ptr &= ~7; > >> + new_gd = (gd_t *)ptr; > >> + memcpy(new_gd, (void *)gd, sizeof(gd_t)); > >> + gd = new_gd; > >> + > >> + /* Clear the BSS. */ > >> + memset(__bss_start, 0, __bss_end - __bss_start); > >> + > >> + return ptr; > >> +#else > >> + return 0; > >> +#endif > >> +} > > > > All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It > > does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so > > the big use case (am335x_boneblack for example where > > CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow > > the area for stack. > > OK I'll have to test more. What sort of problem should i see? We hang on entering env_reloc_spec() which is what puts some big sized variables on the stack. > The return value from spl_relocate_stack_gd() should be shoved into > sp. Does that not happen? It doesn't appear to be. I hadn't broken out the BBB with JTAG tho.
Hi Tom, On 3 March 2015 at 13:14, Tom Rini <trini@konsulko.com> wrote: > On Tue, Mar 03, 2015 at 12:04:16PM -0700, Simon Glass wrote: >> Hi Tom, >> >> On 3 March 2015 at 10:49, Tom Rini <trini@konsulko.com> wrote: >> > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: >> > >> >> At present SPL uses a single stack, either CONFIG_SPL_STACK or >> >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and >> >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to >> >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), >> >> so that the larger stack can be used. >> >> >> >> This is an abuse of lowlevel_init(). That function should only be used for >> >> essential start-up code which cannot be delayed. An example of a valid use is >> >> when only part of the SPL code is visible/executable, and the SoC must be set >> >> up so that board_init_f() can be reached. It should not be used for SDRAM >> >> init, console init, etc. >> >> >> >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new >> >> address before board_init_r() is called in SPL. >> >> >> >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. >> >> >> >> Signed-off-by: Simon Glass <sjg@chromium.org> >> >> For version 1: >> >> Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> >> >> Reviewed-by: Stefan Roese <sr@denx.de> >> >> Tested-by: Bo Shen <voice.shen@atmel.com> >> >> Acked-by: Bo Shen <voice.shen@atmel.com> >> >> Acked-by: Heiko Schocher <hs@denx.de> >> >> Tested-by: Heiko Schocher <hs@denx.de> >> >> --- >> >> >> >> Changes in v6: None >> >> Changes in v5: >> >> - Rebase to master >> >> >> >> Changes in v4: >> >> - Adjust README to mention that lowlevel_init() should have no stack >> >> >> >> Changes in v3: None >> >> Changes in v2: >> >> - Move docs to top-level README file and expand them to cover U-Boot proper >> >> - Add Kconfig settings >> >> >> >> Kconfig | 18 ++++++++++++++ >> >> README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ >> >> arch/arm/lib/crt0.S | 13 +++++++--- >> >> common/spl/spl.c | 35 +++++++++++++++++++++++++++ >> >> 4 files changed, 132 insertions(+), 3 deletions(-) >> > [snip] >> >> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S >> >> index 22df3e5..7939ced 100644 >> >> --- a/arch/arm/lib/crt0.S >> >> +++ b/arch/arm/lib/crt0.S >> >> @@ -113,7 +113,14 @@ here: >> >> /* Set up final (full) environment */ >> >> >> >> bl c_runtime_cpu_setup /* we still call old routine here */ >> >> - >> >> +#endif >> >> +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) >> >> +# ifdef CONFIG_SPL_BUILD >> >> + /* Use a DRAM stack for the rest of SPL, if requested */ >> >> + bl spl_relocate_stack_gd >> >> + cmp r0, #0 >> >> + movne sp, r0 >> >> +# endif >> >> ldr r0, =__bss_start /* this is auto-relocated! */ >> >> ldr r1, =__bss_end /* this is auto-relocated! */ >> >> >> >> @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ >> >> addlo r0, r0, #4 /* move to next */ >> >> blo clbss_l >> >> >> >> +#if ! defined(CONFIG_SPL_BUILD) >> >> bl coloured_LED_init >> >> bl red_led_on >> >> - >> >> +#endif >> >> /* call board_init_r(gd_t *id, ulong dest_addr) */ >> >> mov r0, r9 /* gd_t */ >> >> ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ >> >> @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ >> >> ldr pc, =board_init_r /* this is auto-relocated! */ >> >> >> >> /* we should not return here. */ >> >> - >> >> #endif >> >> >> >> ENDPROC(_main) >> >> diff --git a/common/spl/spl.c b/common/spl/spl.c >> >> index ded0f30..cd75bbc 100644 >> >> --- a/common/spl/spl.c >> >> +++ b/common/spl/spl.c >> >> @@ -281,3 +281,38 @@ void preloader_console_init(void) >> >> spl_display_print(); >> >> #endif >> >> } >> >> + >> >> +/** >> >> + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution >> >> + * >> >> + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM >> >> + * for the main board_init_r() execution. This is typically because we need >> >> + * more stack space for things like the MMC sub-system. >> >> + * >> >> + * This function calculates the stack position, copies the global_data into >> >> + * place and returns the new stack position. The caller is responsible for >> >> + * setting up the sp register. >> >> + * >> >> + * @return new stack location, or 0 to use the same stack >> >> + */ >> >> +ulong spl_relocate_stack_gd(void) >> >> +{ >> >> +#ifdef CONFIG_SPL_STACK_R >> >> + gd_t *new_gd; >> >> + ulong ptr; >> >> + >> >> + /* Get stack position: use 8-byte alignment for ABI compliance */ >> >> + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); >> >> + ptr &= ~7; >> >> + new_gd = (gd_t *)ptr; >> >> + memcpy(new_gd, (void *)gd, sizeof(gd_t)); >> >> + gd = new_gd; >> >> + >> >> + /* Clear the BSS. */ >> >> + memset(__bss_start, 0, __bss_end - __bss_start); >> >> + >> >> + return ptr; >> >> +#else >> >> + return 0; >> >> +#endif >> >> +} >> > >> > All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It >> > does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so >> > the big use case (am335x_boneblack for example where >> > CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow >> > the area for stack. >> >> OK I'll have to test more. What sort of problem should i see? > > We hang on entering env_reloc_spec() which is what puts some big sized > variables on the stack. > >> The return value from spl_relocate_stack_gd() should be shoved into >> sp. Does that not happen? > > It doesn't appear to be. I hadn't broken out the BBB with JTAG tho. I printed out the stack in board_init_r() and it looks right: 32MB above the base of SDRAM. Also I don't seem to get a crash in SPL. How do I make that happen? If I define CONFIG_SPL_USBETH_SUPPORT I get an error about the .data section not fitin in .sram for u-boot-spl. Regards, Simon
On Tue, Mar 03, 2015 at 08:23:23PM -0700, Simon Glass wrote: > Hi Tom, > > On 3 March 2015 at 13:14, Tom Rini <trini@konsulko.com> wrote: > > On Tue, Mar 03, 2015 at 12:04:16PM -0700, Simon Glass wrote: > >> Hi Tom, > >> > >> On 3 March 2015 at 10:49, Tom Rini <trini@konsulko.com> wrote: > >> > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > >> > > >> >> At present SPL uses a single stack, either CONFIG_SPL_STACK or > >> >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > >> >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > >> >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), > >> >> so that the larger stack can be used. > >> >> > >> >> This is an abuse of lowlevel_init(). That function should only be used for > >> >> essential start-up code which cannot be delayed. An example of a valid use is > >> >> when only part of the SPL code is visible/executable, and the SoC must be set > >> >> up so that board_init_f() can be reached. It should not be used for SDRAM > >> >> init, console init, etc. > >> >> > >> >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > >> >> address before board_init_r() is called in SPL. > >> >> > >> >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > >> >> > >> >> Signed-off-by: Simon Glass <sjg@chromium.org> > >> >> For version 1: > >> >> Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> > >> >> Reviewed-by: Stefan Roese <sr@denx.de> > >> >> Tested-by: Bo Shen <voice.shen@atmel.com> > >> >> Acked-by: Bo Shen <voice.shen@atmel.com> > >> >> Acked-by: Heiko Schocher <hs@denx.de> > >> >> Tested-by: Heiko Schocher <hs@denx.de> > >> >> --- > >> >> > >> >> Changes in v6: None > >> >> Changes in v5: > >> >> - Rebase to master > >> >> > >> >> Changes in v4: > >> >> - Adjust README to mention that lowlevel_init() should have no stack > >> >> > >> >> Changes in v3: None > >> >> Changes in v2: > >> >> - Move docs to top-level README file and expand them to cover U-Boot proper > >> >> - Add Kconfig settings > >> >> > >> >> Kconfig | 18 ++++++++++++++ > >> >> README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> >> arch/arm/lib/crt0.S | 13 +++++++--- > >> >> common/spl/spl.c | 35 +++++++++++++++++++++++++++ > >> >> 4 files changed, 132 insertions(+), 3 deletions(-) > >> > [snip] > >> >> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S > >> >> index 22df3e5..7939ced 100644 > >> >> --- a/arch/arm/lib/crt0.S > >> >> +++ b/arch/arm/lib/crt0.S > >> >> @@ -113,7 +113,14 @@ here: > >> >> /* Set up final (full) environment */ > >> >> > >> >> bl c_runtime_cpu_setup /* we still call old routine here */ > >> >> - > >> >> +#endif > >> >> +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) > >> >> +# ifdef CONFIG_SPL_BUILD > >> >> + /* Use a DRAM stack for the rest of SPL, if requested */ > >> >> + bl spl_relocate_stack_gd > >> >> + cmp r0, #0 > >> >> + movne sp, r0 > >> >> +# endif > >> >> ldr r0, =__bss_start /* this is auto-relocated! */ > >> >> ldr r1, =__bss_end /* this is auto-relocated! */ > >> >> > >> >> @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > >> >> addlo r0, r0, #4 /* move to next */ > >> >> blo clbss_l > >> >> > >> >> +#if ! defined(CONFIG_SPL_BUILD) > >> >> bl coloured_LED_init > >> >> bl red_led_on > >> >> - > >> >> +#endif > >> >> /* call board_init_r(gd_t *id, ulong dest_addr) */ > >> >> mov r0, r9 /* gd_t */ > >> >> ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ > >> >> @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > >> >> ldr pc, =board_init_r /* this is auto-relocated! */ > >> >> > >> >> /* we should not return here. */ > >> >> - > >> >> #endif > >> >> > >> >> ENDPROC(_main) > >> >> diff --git a/common/spl/spl.c b/common/spl/spl.c > >> >> index ded0f30..cd75bbc 100644 > >> >> --- a/common/spl/spl.c > >> >> +++ b/common/spl/spl.c > >> >> @@ -281,3 +281,38 @@ void preloader_console_init(void) > >> >> spl_display_print(); > >> >> #endif > >> >> } > >> >> + > >> >> +/** > >> >> + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution > >> >> + * > >> >> + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM > >> >> + * for the main board_init_r() execution. This is typically because we need > >> >> + * more stack space for things like the MMC sub-system. > >> >> + * > >> >> + * This function calculates the stack position, copies the global_data into > >> >> + * place and returns the new stack position. The caller is responsible for > >> >> + * setting up the sp register. > >> >> + * > >> >> + * @return new stack location, or 0 to use the same stack > >> >> + */ > >> >> +ulong spl_relocate_stack_gd(void) > >> >> +{ > >> >> +#ifdef CONFIG_SPL_STACK_R > >> >> + gd_t *new_gd; > >> >> + ulong ptr; > >> >> + > >> >> + /* Get stack position: use 8-byte alignment for ABI compliance */ > >> >> + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); > >> >> + ptr &= ~7; > >> >> + new_gd = (gd_t *)ptr; > >> >> + memcpy(new_gd, (void *)gd, sizeof(gd_t)); > >> >> + gd = new_gd; > >> >> + > >> >> + /* Clear the BSS. */ > >> >> + memset(__bss_start, 0, __bss_end - __bss_start); > >> >> + > >> >> + return ptr; > >> >> +#else > >> >> + return 0; > >> >> +#endif > >> >> +} > >> > > >> > All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It > >> > does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so > >> > the big use case (am335x_boneblack for example where > >> > CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow > >> > the area for stack. > >> > >> OK I'll have to test more. What sort of problem should i see? > > > > We hang on entering env_reloc_spec() which is what puts some big sized > > variables on the stack. > > > >> The return value from spl_relocate_stack_gd() should be shoved into > >> sp. Does that not happen? > > > > It doesn't appear to be. I hadn't broken out the BBB with JTAG tho. > > I printed out the stack in board_init_r() and it looks right: 32MB > above the base of SDRAM. > > Also I don't seem to get a crash in SPL. How do I make that happen? If > I define CONFIG_SPL_USBETH_SUPPORT I get an error about the .data > section not fitin in .sram for u-boot-spl. With v5 at least, am335x_boneblack_config running on a BBB does it. I'll try v6 this morning and see what's going on..
On Wed, Mar 04, 2015 at 08:38:33AM -0500, Tom Rini wrote: > On Tue, Mar 03, 2015 at 08:23:23PM -0700, Simon Glass wrote: > > Hi Tom, > > > > On 3 March 2015 at 13:14, Tom Rini <trini@konsulko.com> wrote: > > > On Tue, Mar 03, 2015 at 12:04:16PM -0700, Simon Glass wrote: > > >> Hi Tom, > > >> > > >> On 3 March 2015 at 10:49, Tom Rini <trini@konsulko.com> wrote: > > >> > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > > >> > > > >> >> At present SPL uses a single stack, either CONFIG_SPL_STACK or > > >> >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > > >> >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > > >> >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), > > >> >> so that the larger stack can be used. > > >> >> > > >> >> This is an abuse of lowlevel_init(). That function should only be used for > > >> >> essential start-up code which cannot be delayed. An example of a valid use is > > >> >> when only part of the SPL code is visible/executable, and the SoC must be set > > >> >> up so that board_init_f() can be reached. It should not be used for SDRAM > > >> >> init, console init, etc. > > >> >> > > >> >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > > >> >> address before board_init_r() is called in SPL. > > >> >> > > >> >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > > >> >> > > >> >> Signed-off-by: Simon Glass <sjg@chromium.org> > > >> >> For version 1: > > >> >> Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> > > >> >> Reviewed-by: Stefan Roese <sr@denx.de> > > >> >> Tested-by: Bo Shen <voice.shen@atmel.com> > > >> >> Acked-by: Bo Shen <voice.shen@atmel.com> > > >> >> Acked-by: Heiko Schocher <hs@denx.de> > > >> >> Tested-by: Heiko Schocher <hs@denx.de> > > >> >> --- > > >> >> > > >> >> Changes in v6: None > > >> >> Changes in v5: > > >> >> - Rebase to master > > >> >> > > >> >> Changes in v4: > > >> >> - Adjust README to mention that lowlevel_init() should have no stack > > >> >> > > >> >> Changes in v3: None > > >> >> Changes in v2: > > >> >> - Move docs to top-level README file and expand them to cover U-Boot proper > > >> >> - Add Kconfig settings > > >> >> > > >> >> Kconfig | 18 ++++++++++++++ > > >> >> README | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > > >> >> arch/arm/lib/crt0.S | 13 +++++++--- > > >> >> common/spl/spl.c | 35 +++++++++++++++++++++++++++ > > >> >> 4 files changed, 132 insertions(+), 3 deletions(-) > > >> > [snip] > > >> >> diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S > > >> >> index 22df3e5..7939ced 100644 > > >> >> --- a/arch/arm/lib/crt0.S > > >> >> +++ b/arch/arm/lib/crt0.S > > >> >> @@ -113,7 +113,14 @@ here: > > >> >> /* Set up final (full) environment */ > > >> >> > > >> >> bl c_runtime_cpu_setup /* we still call old routine here */ > > >> >> - > > >> >> +#endif > > >> >> +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) > > >> >> +# ifdef CONFIG_SPL_BUILD > > >> >> + /* Use a DRAM stack for the rest of SPL, if requested */ > > >> >> + bl spl_relocate_stack_gd > > >> >> + cmp r0, #0 > > >> >> + movne sp, r0 > > >> >> +# endif > > >> >> ldr r0, =__bss_start /* this is auto-relocated! */ > > >> >> ldr r1, =__bss_end /* this is auto-relocated! */ > > >> >> > > >> >> @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > > >> >> addlo r0, r0, #4 /* move to next */ > > >> >> blo clbss_l > > >> >> > > >> >> +#if ! defined(CONFIG_SPL_BUILD) > > >> >> bl coloured_LED_init > > >> >> bl red_led_on > > >> >> - > > >> >> +#endif > > >> >> /* call board_init_r(gd_t *id, ulong dest_addr) */ > > >> >> mov r0, r9 /* gd_t */ > > >> >> ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ > > >> >> @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ > > >> >> ldr pc, =board_init_r /* this is auto-relocated! */ > > >> >> > > >> >> /* we should not return here. */ > > >> >> - > > >> >> #endif > > >> >> > > >> >> ENDPROC(_main) > > >> >> diff --git a/common/spl/spl.c b/common/spl/spl.c > > >> >> index ded0f30..cd75bbc 100644 > > >> >> --- a/common/spl/spl.c > > >> >> +++ b/common/spl/spl.c > > >> >> @@ -281,3 +281,38 @@ void preloader_console_init(void) > > >> >> spl_display_print(); > > >> >> #endif > > >> >> } > > >> >> + > > >> >> +/** > > >> >> + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution > > >> >> + * > > >> >> + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM > > >> >> + * for the main board_init_r() execution. This is typically because we need > > >> >> + * more stack space for things like the MMC sub-system. > > >> >> + * > > >> >> + * This function calculates the stack position, copies the global_data into > > >> >> + * place and returns the new stack position. The caller is responsible for > > >> >> + * setting up the sp register. > > >> >> + * > > >> >> + * @return new stack location, or 0 to use the same stack > > >> >> + */ > > >> >> +ulong spl_relocate_stack_gd(void) > > >> >> +{ > > >> >> +#ifdef CONFIG_SPL_STACK_R > > >> >> + gd_t *new_gd; > > >> >> + ulong ptr; > > >> >> + > > >> >> + /* Get stack position: use 8-byte alignment for ABI compliance */ > > >> >> + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); > > >> >> + ptr &= ~7; > > >> >> + new_gd = (gd_t *)ptr; > > >> >> + memcpy(new_gd, (void *)gd, sizeof(gd_t)); > > >> >> + gd = new_gd; > > >> >> + > > >> >> + /* Clear the BSS. */ > > >> >> + memset(__bss_start, 0, __bss_end - __bss_start); > > >> >> + > > >> >> + return ptr; > > >> >> +#else > > >> >> + return 0; > > >> >> +#endif > > >> >> +} > > >> > > > >> > All of this _does_ move gd into where CONFIG_SPL_STACK_R points. It > > >> > does _not_ move the stack itself into where CONFIG_SPL_STACK_R points so > > >> > the big use case (am335x_boneblack for example where > > >> > CONFIG_SPL_ENV_SUPPORT is set) doesn't work and blows up as we overflow > > >> > the area for stack. > > >> > > >> OK I'll have to test more. What sort of problem should i see? > > > > > > We hang on entering env_reloc_spec() which is what puts some big sized > > > variables on the stack. > > > > > >> The return value from spl_relocate_stack_gd() should be shoved into > > >> sp. Does that not happen? > > > > > > It doesn't appear to be. I hadn't broken out the BBB with JTAG tho. > > > > I printed out the stack in board_init_r() and it looks right: 32MB > > above the base of SDRAM. > > > > Also I don't seem to get a crash in SPL. How do I make that happen? If > > I define CONFIG_SPL_USBETH_SUPPORT I get an error about the .data > > section not fitin in .sram for u-boot-spl. > > With v5 at least, am335x_boneblack_config running on a BBB does it. > I'll try v6 this morning and see what's going on.. With your v6 as-is, things are working. So I'll go track down what's hopefully some problem with what I was doing from here, thanks!
On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > At present SPL uses a single stack, either CONFIG_SPL_STACK or > CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > point into SDRAM. They then set up SDRAM very early, before board_init_f(), > so that the larger stack can be used. > > This is an abuse of lowlevel_init(). That function should only be used for > essential start-up code which cannot be delayed. An example of a valid use is > when only part of the SPL code is visible/executable, and the SoC must be set > up so that board_init_f() can be reached. It should not be used for SDRAM > init, console init, etc. > > Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > address before board_init_r() is called in SPL. > > The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. [snip] > diff --git a/Kconfig b/Kconfig > index 91a0618..8de731d 100644 > --- a/Kconfig > +++ b/Kconfig > @@ -96,6 +96,24 @@ config SPL > help > If you want to build SPL as well as the normal image, say Y. > > +config CONFIG_SPL_STACK_R > + depends on SPL > + bool "Enable SDRAM location for SPL stack" > + help > + SPL starts off execution in SRAM and thus typically has only a small > + stack available. Since SPL sets up DRAM while in its board_init_f() > + function, it is possible for the stack to move there before > + board_init_r() is reached. This option enables a special SDRAM > + location for the SPL stack. U-Boot SPL switches to this after > + board_init_f() completes, and before board_init_r() starts. > + > +config CONFIG_SPL_STACK_R_ADDR > + depends on CONFIG_SPL_STACK_R I found my problem! Incorrect Kconfig syntax, no CONFIG_ in 'config' or 'depends' lines only help lines. So I was right in that my stack wasn't moving because I was doing it via the defconfig and that was broken :) I'm just going to pick up 1-5 (with this fixed) and send out my own 6 after I test it on omap3 and omap4/5 which also need a similar conversion.
Hi Tom, On 4 March 2015 at 08:42, Tom Rini <trini@konsulko.com> wrote: > On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > >> At present SPL uses a single stack, either CONFIG_SPL_STACK or >> CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and >> environment) require a lot of stack, some boards set CONFIG_SPL_STACK to >> point into SDRAM. They then set up SDRAM very early, before board_init_f(), >> so that the larger stack can be used. >> >> This is an abuse of lowlevel_init(). That function should only be used for >> essential start-up code which cannot be delayed. An example of a valid use is >> when only part of the SPL code is visible/executable, and the SoC must be set >> up so that board_init_f() can be reached. It should not be used for SDRAM >> init, console init, etc. >> >> Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new >> address before board_init_r() is called in SPL. >> >> The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > [snip] >> diff --git a/Kconfig b/Kconfig >> index 91a0618..8de731d 100644 >> --- a/Kconfig >> +++ b/Kconfig >> @@ -96,6 +96,24 @@ config SPL >> help >> If you want to build SPL as well as the normal image, say Y. >> >> +config CONFIG_SPL_STACK_R >> + depends on SPL >> + bool "Enable SDRAM location for SPL stack" >> + help >> + SPL starts off execution in SRAM and thus typically has only a small >> + stack available. Since SPL sets up DRAM while in its board_init_f() >> + function, it is possible for the stack to move there before >> + board_init_r() is reached. This option enables a special SDRAM >> + location for the SPL stack. U-Boot SPL switches to this after >> + board_init_f() completes, and before board_init_r() starts. >> + >> +config CONFIG_SPL_STACK_R_ADDR >> + depends on CONFIG_SPL_STACK_R > > I found my problem! Incorrect Kconfig syntax, no CONFIG_ in 'config' or > 'depends' lines only help lines. So I was right in that my stack wasn't > moving because I was doing it via the defconfig and that was broken :) > > I'm just going to pick up 1-5 (with this fixed) and send out my own 6 > after I test it on omap3 and omap4/5 which also need a similar > conversion. Great, thanks for doing this! Regards, Simon
On Tue, Mar 03, 2015 at 08:03:00AM -0700, Simon Glass wrote: > At present SPL uses a single stack, either CONFIG_SPL_STACK or > CONFIG_SYS_INIT_SP_ADDR. Since some SPL features (such as MMC and > environment) require a lot of stack, some boards set CONFIG_SPL_STACK to > point into SDRAM. They then set up SDRAM very early, before board_init_f(), > so that the larger stack can be used. > > This is an abuse of lowlevel_init(). That function should only be used for > essential start-up code which cannot be delayed. An example of a valid use is > when only part of the SPL code is visible/executable, and the SoC must be set > up so that board_init_f() can be reached. It should not be used for SDRAM > init, console init, etc. > > Add a CONFIG_SPL_STACK_R option, which allows the stack to be moved to a new > address before board_init_r() is called in SPL. > > The expected SPL flow (for CONFIG_SPL_FRAMEWORK) is documented in the README. > > Signed-off-by: Simon Glass <sjg@chromium.org> > For version 1: > Acked-by: Albert ARIBAUD <albert.u.boot@aribaud.net> > Reviewed-by: Stefan Roese <sr@denx.de> > Tested-by: Bo Shen <voice.shen@atmel.com> > Acked-by: Bo Shen <voice.shen@atmel.com> > Acked-by: Heiko Schocher <hs@denx.de> > Tested-by: Heiko Schocher <hs@denx.de> After fixing the Kconfig part to not have 'CONFIG_' in the 'config' and 'depends' lines, applied to u-boot/master, thanks!
diff --git a/Kconfig b/Kconfig index 91a0618..8de731d 100644 --- a/Kconfig +++ b/Kconfig @@ -96,6 +96,24 @@ config SPL help If you want to build SPL as well as the normal image, say Y. +config CONFIG_SPL_STACK_R + depends on SPL + bool "Enable SDRAM location for SPL stack" + help + SPL starts off execution in SRAM and thus typically has only a small + stack available. Since SPL sets up DRAM while in its board_init_f() + function, it is possible for the stack to move there before + board_init_r() is reached. This option enables a special SDRAM + location for the SPL stack. U-Boot SPL switches to this after + board_init_f() completes, and before board_init_r() starts. + +config CONFIG_SPL_STACK_R_ADDR + depends on CONFIG_SPL_STACK_R + hex "SDRAM location for SPL stack" + help + Specify the address in SDRAM for the SPL stack. This will be set up + before board_init_r() is called. + config TPL bool depends on SPL && SUPPORT_TPL diff --git a/README b/README index febefb5..3547ead 100644 --- a/README +++ b/README @@ -273,6 +273,75 @@ run some of U-Boot's tests. See board/sandbox/README.sandbox for more details. +Board Initialisation Flow: +-------------------------- + +This is the intended start-up flow for boards. This should apply for both +SPL and U-Boot proper (i.e. they both follow the same rules). At present SPL +mostly uses a separate code path, but the funtion names and roles of each +function are the same. Some boards or architectures may not conform to this. +At least most ARM boards which use CONFIG_SPL_FRAMEWORK conform to this. + +Execution starts with start.S with three functions called during init after +that. The purpose and limitations of each is described below. + +lowlevel_init(): + - purpose: essential init to permit execution to reach board_init_f() + - no global_data or BSS + - there is no stack (ARMv7 may have one but it will soon be removed) + - must not set up SDRAM or use console + - must only do the bare minimum to allow execution to continue to + board_init_f() + - this is almost never needed + - return normally from this function + +board_init_f(): + - purpose: set up the machine ready for running board_init_r(): + i.e. SDRAM and serial UART + - global_data is available + - stack is in SRAM + - BSS is not available, so you cannot use global/static variables, + only stack variables and global_data + + Non-SPL-specific notes: + - dram_init() is called to set up DRAM. If already done in SPL this + can do nothing + + SPL-specific notes: + - you can override the entire board_init_f() function with your own + version as needed. + - preloader_console_init() can be called here in extremis + - should set up SDRAM, and anything needed to make the UART work + - these is no need to clear BSS, it will be done by crt0.S + - must return normally from this function (don't call board_init_r() + directly) + +Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at +this point the stack and global_data are relocated to below +CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of +memory. + +board_init_r(): + - purpose: main execution, common code + - global_data is available + - SDRAM is available + - BSS is available, all static/global variables can be used + - execution eventually continues to main_loop() + + Non-SPL-specific notes: + - U-Boot is relocated to the top of memory and is now running from + there. + + SPL-specific notes: + - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and + CONFIG_SPL_STACK_R_ADDR points into SDRAM + - preloader_console_init() can be called here - typically this is + done by defining CONFIG_SPL_BOARD_INIT and then supplying a + spl_board_init() function containing this call + - loads U-Boot or (in falcon mode) Linux + + + Configuration Options: ---------------------- diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index 22df3e5..7939ced 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -113,7 +113,14 @@ here: /* Set up final (full) environment */ bl c_runtime_cpu_setup /* we still call old routine here */ - +#endif +#if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_FRAMEWORK) +# ifdef CONFIG_SPL_BUILD + /* Use a DRAM stack for the rest of SPL, if requested */ + bl spl_relocate_stack_gd + cmp r0, #0 + movne sp, r0 +# endif ldr r0, =__bss_start /* this is auto-relocated! */ ldr r1, =__bss_end /* this is auto-relocated! */ @@ -124,9 +131,10 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ addlo r0, r0, #4 /* move to next */ blo clbss_l +#if ! defined(CONFIG_SPL_BUILD) bl coloured_LED_init bl red_led_on - +#endif /* call board_init_r(gd_t *id, ulong dest_addr) */ mov r0, r9 /* gd_t */ ldr r1, [r9, #GD_RELOCADDR] /* dest_addr */ @@ -134,7 +142,6 @@ clbss_l:cmp r0, r1 /* while not at end of BSS */ ldr pc, =board_init_r /* this is auto-relocated! */ /* we should not return here. */ - #endif ENDPROC(_main) diff --git a/common/spl/spl.c b/common/spl/spl.c index ded0f30..cd75bbc 100644 --- a/common/spl/spl.c +++ b/common/spl/spl.c @@ -281,3 +281,38 @@ void preloader_console_init(void) spl_display_print(); #endif } + +/** + * spl_relocate_stack_gd() - Relocate stack ready for board_init_r() execution + * + * Sometimes board_init_f() runs with a stack in SRAM but we want to use SDRAM + * for the main board_init_r() execution. This is typically because we need + * more stack space for things like the MMC sub-system. + * + * This function calculates the stack position, copies the global_data into + * place and returns the new stack position. The caller is responsible for + * setting up the sp register. + * + * @return new stack location, or 0 to use the same stack + */ +ulong spl_relocate_stack_gd(void) +{ +#ifdef CONFIG_SPL_STACK_R + gd_t *new_gd; + ulong ptr; + + /* Get stack position: use 8-byte alignment for ABI compliance */ + ptr = CONFIG_SPL_STACK_R - sizeof(gd_t); + ptr &= ~7; + new_gd = (gd_t *)ptr; + memcpy(new_gd, (void *)gd, sizeof(gd_t)); + gd = new_gd; + + /* Clear the BSS. */ + memset(__bss_start, 0, __bss_end - __bss_start); + + return ptr; +#else + return 0; +#endif +}