[U-Boot] [PATCH v2] Fix board init code to use a valid C runtime environment

board_init_f_mem() alters the C runtime environment's stack it ls actually already using. This is not a valid C runtime environment.
Split board_init_f_mem into C functions which do not alter their own stack and therefore run in a valid C runtime environment.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net --- For NIOS2, this patch hopefully contains all manual fixes by Thomas.
Changes in v2: - Fix all checkpatch issues - Fix board_init_f_malloc prototype mismatch - Fix board_init_[f_]xxx typo in NIOS2 - Fix aarch64 asm 'sub' syntax error
arch/arc/lib/start.S | 20 +++++++++++++--- arch/arm/lib/crt0.S | 10 ++++++-- arch/arm/lib/crt0_64.S | 10 ++++++-- arch/microblaze/cpu/start.S | 4 ++-- arch/nios2/cpu/start.S | 17 ++++++++++++-- arch/powerpc/cpu/ppc4xx/start.S | 18 ++++++++++---- arch/x86/cpu/start.S | 10 ++++++-- arch/x86/lib/fsp/fsp_common.c | 4 ++-- common/init/board_init.c | 31 ++++++++++++++---------- include/common.h | 52 +++++++++++++++++++++++++---------------- 10 files changed, 125 insertions(+), 51 deletions(-)
diff --git a/arch/arc/lib/start.S b/arch/arc/lib/start.S index 26a5934..d24d60b 100644 --- a/arch/arc/lib/start.S +++ b/arch/arc/lib/start.S @@ -54,14 +54,28 @@ ENTRY(_start) mov %sp, CONFIG_SYS_INIT_SP_ADDR mov %fp, %sp
- /* Allocate and zero GD, update SP */ + /* Allocate GD, update SP */ mov %r0, %sp - bl board_init_f_mem + bl board_init_f_gd_size + /* Update stack- and frame-pointers */ + sub %sp, %sp, %r0 + mov %fp, %sp + + /* Zero GD */ + mov %r0, %sp + bl board_init_f_gd
+ /* Allocate malloc, update SP */ + mov %r0, %sp + bl board_init_f_malloc_size /* Update stack- and frame-pointers */ - mov %sp, %r0 + sub %sp, %sp, %r0 mov %fp, %sp
+ /* update GD with malloc base */ + mov %r0, %sp + bl board_init_f_malloc + /* Zero the one and only argument of "board_init_f" */ mov_s %r0, 0 j board_init_f diff --git a/arch/arm/lib/crt0.S b/arch/arm/lib/crt0.S index 80548eb..26abab7 100644 --- a/arch/arm/lib/crt0.S +++ b/arch/arm/lib/crt0.S @@ -82,9 +82,15 @@ ENTRY(_main) #else bic sp, sp, #7 /* 8-byte alignment for ABI compliance */ #endif + bl board_init_f_gd_size + sub sp, r0 mov r0, sp - bl board_init_f_mem - mov sp, r0 + mov r9, r0 + bl board_init_f_gd + bl board_init_f_malloc_size + sub sp, r0 + mov r0, sp + bl board_init_f_malloc
mov r0, #0 bl board_init_f diff --git a/arch/arm/lib/crt0_64.S b/arch/arm/lib/crt0_64.S index cef1c71..00cef36 100644 --- a/arch/arm/lib/crt0_64.S +++ b/arch/arm/lib/crt0_64.S @@ -75,8 +75,14 @@ ENTRY(_main) ldr x0, =(CONFIG_SYS_INIT_SP_ADDR) #endif bic sp, x0, #0xf /* 16-byte alignment for ABI compliance */ - bl board_init_f_mem - mov sp, x0 + bl board_init_f_gd_size + sub sp, sp, x0 + mov x0, sp + bl board_init_f_gd + bl board_init_f_malloc_size + sub sp, sp, x0 + mov x0, sp + bl board_init_f_malloc
mov x0, #0 bl board_init_f diff --git a/arch/microblaze/cpu/start.S b/arch/microblaze/cpu/start.S index 14f46a8..206be3e 100644 --- a/arch/microblaze/cpu/start.S +++ b/arch/microblaze/cpu/start.S @@ -25,7 +25,7 @@ _start:
addi r8, r0, __end mts rslr, r8 - /* TODO: Redo this code to call board_init_f_mem() */ + /* TODO: Redo this code to call board_init_f_*() */ #if defined(CONFIG_SPL_BUILD) addi r1, r0, CONFIG_SPL_STACK_ADDR mts rshr, r1 @@ -142,7 +142,7 @@ _start: ori r12, r12, 0x1a0 mts rmsr, r12
- /* TODO: Redo this code to call board_init_f_mem() */ + /* TODO: Redo this code to call board_init_f_*() */ clear_bss: /* clear BSS segments */ addi r5, r0, __bss_start diff --git a/arch/nios2/cpu/start.S b/arch/nios2/cpu/start.S index 54787c5..c163ce1 100644 --- a/arch/nios2/cpu/start.S +++ b/arch/nios2/cpu/start.S @@ -107,9 +107,22 @@ _reloc: mov fp, sp
/* Allocate and zero GD, update SP */ + movhi r2, %hi(board_init_f_gd_size@h) + ori r2, r2, %lo(board_init_f_gd_size@h) + callr r2 + sub sp, sp, r4 + mov r4, sp + movhi r2, %hi(board_init_f_gd@h) + ori r2, r2, %lo(board_init_f_gd@h) + callr r2 + /* Allocate malloc arena, update SP */ + movhi r2, %hi(board_init_f_malloc_size@h) + ori r2, r2, %lo(board_init_f_malloc_size@h) + callr r2 + sub sp, sp, r4 mov r4, sp - movhi r2, %hi(board_init_f_mem@h) - ori r2, r2, %lo(board_init_f_mem@h) + movhi r2, %hi(board_init_f_malloc@h) + ori r2, r2, %lo(board_init_f_malloc@h) callr r2
/* Update stack- and frame-pointers */ diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S index 77d4040..c827c95 100644 --- a/arch/powerpc/cpu/ppc4xx/start.S +++ b/arch/powerpc/cpu/ppc4xx/start.S @@ -761,9 +761,14 @@ _start:
bl cpu_init_f /* run low-level CPU init code (from Flash) */ #ifdef CONFIG_SYS_GENERIC_BOARD + bl board_init_f_gd_size + sub r1, r1, r3 mr r3, r1 - bl board_init_f_mem - mr r1, r3 + bl board_init_f_gd + bl board_init_f_malloc_size + sub r1, r1, r3 + mr r3, r1 + bl board_init_f_malloc li r0,0 stwu r0, -4(r1) stwu r0, -4(r1) @@ -1037,9 +1042,14 @@ _start:
bl cpu_init_f /* run low-level CPU init code (from Flash) */ #ifdef CONFIG_SYS_GENERIC_BOARD + bl board_init_f_gd_size + sub r1, r1, r3 + mr r3, r1 + bl board_init_f_gd + bl board_init_f_malloc_size + sub r1, r1, r3 mr r3, r1 - bl board_init_f_mem - mr r1, r3 + bl board_init_f_malloc stwu r0, -4(r1) stwu r0, -4(r1) #endif diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index 5b4ee79..25ac286 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -122,9 +122,15 @@ car_init_ret: */ #endif /* Set up global data */ + call board_init_f_gd_size + subl %esp, %eax mov %esp, %eax - call board_init_f_mem - mov %eax, %esp + call board_init_f_gd + /* Set up malloc arena */ + call board_init_f_malloc_size + subl %esp, %eax + mov %esp, %eax + call board_init_f_malloc
#ifdef CONFIG_DEBUG_UART call debug_uart_init diff --git a/arch/x86/lib/fsp/fsp_common.c b/arch/x86/lib/fsp/fsp_common.c index c78df94..5249455 100644 --- a/arch/x86/lib/fsp/fsp_common.c +++ b/arch/x86/lib/fsp/fsp_common.c @@ -95,8 +95,8 @@ int x86_fsp_init(void) /* * The second time we enter here, adjust the size of malloc() * pool before relocation. Given gd->malloc_base was adjusted - * after the call to board_init_f_mem() in arch/x86/cpu/start.S, - * we should fix up gd->malloc_limit here. + * after the call to board_init_f_malloc() in arch/x86/cpu/ + * start.S, we should fix up gd->malloc_limit here. */ gd->malloc_limit += CONFIG_FSP_SYS_MALLOC_F_LEN; } diff --git a/common/init/board_init.c b/common/init/board_init.c index e74b63b..8839a4a 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -29,32 +29,39 @@ __weak void arch_setup_gd(struct global_data *gd_ptr) } #endif /* !CONFIG_X86 */
-ulong board_init_f_mem(ulong top) +ulong board_init_f_gd_size(void) +{ + return roundup(sizeof(struct global_data), 16); +} + +void board_init_f_gd(struct global_data *gd_ptr) { - struct global_data *gd_ptr; #ifndef _USE_MEMCPY int *ptr; #endif
- /* Leave space for the stack we are running with now */ - top -= 0x40; - - top -= sizeof(struct global_data); - top = ALIGN(top, 16); - gd_ptr = (struct global_data *)top; #ifdef _USE_MEMCPY memset(gd_ptr, '\0', sizeof(*gd)); #else for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif - arch_setup_gd(gd_ptr); +}
+ulong board_init_f_malloc_size(void) +{ #if defined(CONFIG_SYS_MALLOC_F) && \ (!defined(CONFIG_SPL_BUILD) || !defined(CONFIG_SYS_SPL_MALLOC_START)) - top -= CONFIG_SYS_MALLOC_F_LEN; - gd->malloc_base = top; + return CONFIG_SYS_MALLOC_F_LEN; +#else + return 0; #endif +}
- return top; +void board_init_f_malloc(ulong malloc_base) +{ +#if defined(CONFIG_SYS_MALLOC_F) && \ + (!defined(CONFIG_SPL_BUILD) || !defined(CONFIG_SYS_SPL_MALLOC_START)) + gd->malloc_base = malloc_base; +#endif } diff --git a/include/common.h b/include/common.h index 09a131d..a2d81d9 100644 --- a/include/common.h +++ b/include/common.h @@ -225,32 +225,44 @@ void board_init_f(ulong); void board_init_r(gd_t *, ulong) __attribute__ ((noreturn));
/** - * board_init_f_mem() - Allocate global data and set stack position + * board_init_f_gd_size() - Return the size of the global data * * This function is called by each architecture very early in the start-up - * code to set up the environment for board_init_f(). It allocates space for - * global_data (see include/asm-generic/global_data.h) and places the stack - * below this. + * code to allow the C runtime to reserve space for the GD on the stack. * - * This function requires a stack[1] Normally this is at @top. The function - * starts allocating space from 64 bytes below @top. First it creates space - * for global_data. Then it calls arch_setup_gd() which sets gd to point to - * the global_data space and can reserve additional bytes of space if - * required). Finally it allocates early malloc() memory - * (CONFIG_SYS_MALLOC_F_LEN). The new top of the stack is just below this, - * and it returned by this function. + * @return: GD size + */ +ulong board_init_f_gd_size(void); + +/** + * board_init_f_gd() - Initialize (zero) the global data + * + * This function is called once the C runtime has allocated the GD on + * the stack. It must initialize the GD. + * + * @gd_ptr: the pointer to the GD to initialize + */ +void board_init_f_gd(struct global_data *gd_ptr); + +/** + * board_init_f_malloc_size() - Return the size of the malloc arena + * + * This function is called once the GD is initialized, to allow the C + * runtime to allocate the malloc arena on the stack. + * + * @return: Malloc arena size + */ +ulong board_init_f_malloc_size(void); + +/** + * board_init_f_malloc() - Mark the malloc arena base in the global data * - * [1] Strictly speaking it would be possible to implement this function - * in C on many archs such that it does not require a stack. However this - * does not seem hugely important as only 64 byte are wasted. The 64 bytes - * are used to handle the calling standard which generally requires pushing - * addresses or registers onto the stack. We should be able to get away with - * less if this becomes important. + * This function is called once the malloc arena is allocated on the + * stack. It marks the malloc arena base in the global data. * - * @top: Top of available memory, also normally the top of the stack - * @return: New stack location + * @malloc_base: the base of the malloc arena */ -ulong board_init_f_mem(ulong top); +void board_init_f_malloc(ulong malloc_base);
/** * arch_setup_gd() - Set up the global_data pointer

On Tue, 10 Nov 2015 19:30:47 +0100, Albert ARIBAUD albert.u.boot@aribaud.net wrote:
board_init_f_mem() alters the C runtime environment's stack it ls actually already using. This is not a valid C runtime environment.
Split board_init_f_mem into C functions which do not alter their own stack and therefore run in a valid C runtime environment.
Additional note: tested with current u-boot/master (commit cad04990) on an OpenRD-Client board (which builds Thumb-1 code) using gcc 5.2.1 (which saves and restores r9 in just about any C function, causing arch_setup_gd to fail setting GD):
- without this patch, the board fails to boot with an undefined instruction exception.
- with this patch, the board boots and functions normally (at least dhcp, tftp, go are working as expected).
Amicalement,

Hi Albert,
On 2015年11月11日 02:30, Albert ARIBAUD wrote:
board_init_f_mem() alters the C runtime environment's stack it ls actually already using. This is not a valid C runtime environment.
Split board_init_f_mem into C functions which do not alter their own stack and therefore run in a valid C runtime environment.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net
For NIOS2, this patch hopefully contains all manual fixes by Thomas.
Changes in v2:
Fix all checkpatch issues
Fix board_init_f_malloc prototype mismatch
Fix board_init_[f_]xxx typo in NIOS2
Fix aarch64 asm 'sub' syntax error
arch/arc/lib/start.S | 20 +++++++++++++--- arch/arm/lib/crt0.S | 10 ++++++-- arch/arm/lib/crt0_64.S | 10 ++++++-- arch/microblaze/cpu/start.S | 4 ++-- arch/nios2/cpu/start.S | 17 ++++++++++++-- arch/powerpc/cpu/ppc4xx/start.S | 18 ++++++++++---- arch/x86/cpu/start.S | 10 ++++++-- arch/x86/lib/fsp/fsp_common.c | 4 ++-- common/init/board_init.c | 31 ++++++++++++++---------- include/common.h | 52 +++++++++++++++++++++++++---------------- 10 files changed, 125 insertions(+), 51 deletions(-)
Additional fixes, ------------------------------------------------------------------------ diff --git a/common/init/board_init.c b/common/init/board_init.c index 8839a4a..703e6d8 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -46,6 +46,7 @@ void board_init_f_gd(struct global_data *gd_ptr) for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif + arch_setup_gd(gd_ptr); }
ulong board_init_f_malloc_size(void) -------------------------------------------------------------------------- diff --git a/arch/nios2/cpu/start.S b/arch/nios2/cpu/start.S index c163ce1..0adff46 100644 --- a/arch/nios2/cpu/start.S +++ b/arch/nios2/cpu/start.S @@ -110,7 +110,7 @@ _reloc: movhi r2, %hi(board_init_f_gd_size@h) ori r2, r2, %lo(board_init_f_gd_size@h) callr r2 - sub sp, sp, r4 + sub sp, sp, r2 mov r4, sp movhi r2, %hi(board_init_f_gd@h) ori r2, r2, %lo(board_init_f_gd@h) @@ -119,16 +119,12 @@ _reloc: movhi r2, %hi(board_init_f_malloc_size@h) ori r2, r2, %lo(board_init_f_malloc_size@h) callr r2 - sub sp, sp, r4 + sub sp, sp, r2 mov r4, sp movhi r2, %hi(board_init_f_malloc@h) ori r2, r2, %lo(board_init_f_malloc@h) callr r2
- /* Update stack- and frame-pointers */ - mov sp, r2 - mov fp, sp - /* Call board_init_f -- never returns */ mov r4, r0 movhi r2, %hi(board_init_f@h) ---------------------------------------------------------------------------- Otherwise,
Tested-by: Thomas Chou thomas@wytron.com.tw Acked-by: Thomas Chou thomas@wytron.com.tw
Thanks.
Best regards, Thomas

Hello Thomas,
On Thu, 12 Nov 2015 13:59:28 +0800, Thomas Chou thomas@wytron.com.tw wrote:
Hi Albert,
On 2015年11月11日 02:30, Albert ARIBAUD wrote:
board_init_f_mem() alters the C runtime environment's stack it ls actually already using. This is not a valid C runtime environment.
Split board_init_f_mem into C functions which do not alter their own stack and therefore run in a valid C runtime environment.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net
For NIOS2, this patch hopefully contains all manual fixes by Thomas.
Changes in v2:
Fix all checkpatch issues
Fix board_init_f_malloc prototype mismatch
Fix board_init_[f_]xxx typo in NIOS2
Fix aarch64 asm 'sub' syntax error
arch/arc/lib/start.S | 20 +++++++++++++--- arch/arm/lib/crt0.S | 10 ++++++-- arch/arm/lib/crt0_64.S | 10 ++++++-- arch/microblaze/cpu/start.S | 4 ++-- arch/nios2/cpu/start.S | 17 ++++++++++++-- arch/powerpc/cpu/ppc4xx/start.S | 18 ++++++++++---- arch/x86/cpu/start.S | 10 ++++++-- arch/x86/lib/fsp/fsp_common.c | 4 ++-- common/init/board_init.c | 31 ++++++++++++++---------- include/common.h | 52 +++++++++++++++++++++++++---------------- 10 files changed, 125 insertions(+), 51 deletions(-)
Additional fixes,
diff --git a/common/init/board_init.c b/common/init/board_init.c index 8839a4a..703e6d8 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -46,6 +46,7 @@ void board_init_f_gd(struct global_data *gd_ptr) for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif
- arch_setup_gd(gd_ptr);
Correct -- in ARM (Thumb-1 at least) we cannot use arch_setup_gd() so we set GD (in r9) from within arch/arm/lib/crt0.S, but for NIOS2 it might (and apparently does) work. Where is GD stored in NIOS2?
}
ulong board_init_f_malloc_size(void)
diff --git a/arch/nios2/cpu/start.S b/arch/nios2/cpu/start.S index c163ce1..0adff46 100644 --- a/arch/nios2/cpu/start.S +++ b/arch/nios2/cpu/start.S @@ -110,7 +110,7 @@ _reloc: movhi r2, %hi(board_init_f_gd_size@h) ori r2, r2, %lo(board_init_f_gd_size@h) callr r2
- sub sp, sp, r4
- sub sp, sp, r2
Sorry, didn't know / realize the NIOS2 ABI has r2 iass the function value return register, not r4.
mov r4, sp movhi r2, %hi(board_init_f_gd@h) ori r2, r2, %lo(board_init_f_gd@h) @@ -119,16 +119,12 @@ _reloc: movhi r2, %hi(board_init_f_malloc_size@h) ori r2, r2, %lo(board_init_f_malloc_size@h) callr r2
- sub sp, sp, r4
- sub sp, sp, r2
Ditto.
mov r4, sp movhi r2, %hi(board_init_f_malloc@h) ori r2, r2, %lo(board_init_f_malloc@h) callr r2
- /* Update stack- and frame-pointers */
- mov sp, r2
- mov fp, sp
Oops.
/* Call board_init_f -- never returns */ mov r4, r0 movhi r2, %hi(board_init_f@h)
Otherwise,
Tested-by: Thomas Chou thomas@wytron.com.tw Acked-by: Thomas Chou thomas@wytron.com.tw
Thanks.
Thanks to you; Will send a v3 to account for your and Simon's comments.
Best regards, Thomas
Amicalement,

Hi Albert,
On 2015年11月12日 15:17, Albert ARIBAUD wrote:
diff --git a/common/init/board_init.c b/common/init/board_init.c index 8839a4a..703e6d8 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -46,6 +46,7 @@ void board_init_f_gd(struct global_data *gd_ptr) for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif
- arch_setup_gd(gd_ptr);
Correct -- in ARM (Thumb-1 at least) we cannot use arch_setup_gd() so we set GD (in r9) from within arch/arm/lib/crt0.S, but for NIOS2 it might (and apparently does) work. Where is GD stored in NIOS2?
It is a register, r26 "gp".
I have another question. Will it be simpler to have two calls instead of four?
1. get size of gd plus malloc.
2. init gd and malloc.
Best regards, Thomas

Hello Thomas,
On Thu, 12 Nov 2015 16:28:38 +0800, Thomas Chou thomas@wytron.com.tw wrote:
Hi Albert,
On 2015年11月12日 15:17, Albert ARIBAUD wrote:
diff --git a/common/init/board_init.c b/common/init/board_init.c index 8839a4a..703e6d8 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -46,6 +46,7 @@ void board_init_f_gd(struct global_data *gd_ptr) for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif
- arch_setup_gd(gd_ptr);
Correct -- in ARM (Thumb-1 at least) we cannot use arch_setup_gd() so we set GD (in r9) from within arch/arm/lib/crt0.S, but for NIOS2 it might (and apparently does) work. Where is GD stored in NIOS2?
It is a register, r26 "gp".
Ok. In ARM it is r9, and gcc is prevented from ever using r9 by adding the compiler option -ffixed-r9 to the compiler command lines. I guess the same goes for NIOS2 -- maybe the NIOS2 gcc does not even need an option, and always leaves gp/r26 alone.
I have another question. Will it be simpler to have two calls instead of four?
get size of gd plus malloc.
init gd and malloc.
I'd hinted at reducing the number of functions, but not the number of calls, in my reply to Simon Glass in this thread, see here: http://article.gmane.org/gmane.comp.boot-loaders.u-boot/240520
Your proposal might indeed help reducing the number of calls as well.
The first function would receive the current top of the stack and would subtract the (aligned) gd then the (aligned) malloc arena size, and return the new top-of-stack, which the C runtime code would enforce in sp (or whatever the equivalent is in each arch) -- BUT it would not write anything in that space as it would not be reserved at that point.
The second function would receive this new top-of-stack again, this time as a base of the reserved space (or it could receive the old top-of-stack and work its way downward) and would be able to safely write whatever it wants inside this space.
The only caveat is, we need to be sure that the second function can reconstruct the base addresses of all allocated chunks (gd, malloc, whatever they'll be wanting to add later) just like the first function computed them (it could still be a single function called twice as I'd suggested, BTW).
Thanks for the suggestion! I'll consider it for v3.
Best regards, Thomas
Amicalement,

Hello Thomas,
On Thu, 12 Nov 2015 13:59:28 +0800, Thomas Chou thomas@wytron.com.tw wrote:
Hi Albert,
- /* Update stack- and frame-pointers */
- mov sp, r2
- mov fp, sp
Just a sec here on second thought.
I understand the 'mov sp, r2' must be removed as it is replaced by a 'sub sp, sp, r2' a few lines earlier.
But doesn't the 'mov fp, sp' need to remain? Without it, fp is not set any more, is it?
Best regards, Thomas
Amicalement,

Hi Albert,
On 2015年11月13日 14:41, Albert ARIBAUD wrote:
Hello Thomas,
On Thu, 12 Nov 2015 13:59:28 +0800, Thomas Chou thomas@wytron.com.tw wrote:
Hi Albert,
- /* Update stack- and frame-pointers */
- mov sp, r2
- mov fp, sp
Just a sec here on second thought.
I understand the 'mov sp, r2' must be removed as it is replaced by a 'sub sp, sp, r2' a few lines earlier.
But doesn't the 'mov fp, sp' need to remain? Without it, fp is not set any more, is it?
Yes, the 'mov fp, sp' need to remain. I forgot to add them.
Best regards, Thomas

Hi Albert,
On Wed, Nov 11, 2015 at 2:30 AM, Albert ARIBAUD albert.u.boot@aribaud.net wrote:
board_init_f_mem() alters the C runtime environment's stack it ls actually already using. This is not a valid C runtime environment.
Split board_init_f_mem into C functions which do not alter their own stack and therefore run in a valid C runtime environment.
Signed-off-by: Albert ARIBAUD albert.u.boot@aribaud.net
Thank you for the other long email thread explaining the details. It's really helpful to understand the problem we are trying to resolve here.
For NIOS2, this patch hopefully contains all manual fixes by Thomas.
I've tested the patch on x86 boards, but it does not boot :( Please check my fixes (3 places) below.
Changes in v2:
- Fix all checkpatch issues
- Fix board_init_f_malloc prototype mismatch
- Fix board_init_[f_]xxx typo in NIOS2
- Fix aarch64 asm 'sub' syntax error
arch/arc/lib/start.S | 20 +++++++++++++--- arch/arm/lib/crt0.S | 10 ++++++-- arch/arm/lib/crt0_64.S | 10 ++++++-- arch/microblaze/cpu/start.S | 4 ++-- arch/nios2/cpu/start.S | 17 ++++++++++++-- arch/powerpc/cpu/ppc4xx/start.S | 18 ++++++++++---- arch/x86/cpu/start.S | 10 ++++++-- arch/x86/lib/fsp/fsp_common.c | 4 ++-- common/init/board_init.c | 31 ++++++++++++++---------- include/common.h | 52 +++++++++++++++++++++++++---------------- 10 files changed, 125 insertions(+), 51 deletions(-)
[snip]
diff --git a/arch/x86/cpu/start.S b/arch/x86/cpu/start.S index 5b4ee79..25ac286 100644 --- a/arch/x86/cpu/start.S +++ b/arch/x86/cpu/start.S @@ -122,9 +122,15 @@ car_init_ret: */ #endif /* Set up global data */
call board_init_f_gd_size
subl %esp, %eax
I guess you are confused by the AT&T assembly syntax. This should be: subl %eax, %esp.
mov %esp, %eax
call board_init_f_mem
mov %eax, %esp
call board_init_f_gd
/* Set up malloc arena */
call board_init_f_malloc_size
subl %esp, %eax
Ditto.
mov %esp, %eax
call board_init_f_malloc
#ifdef CONFIG_DEBUG_UART call debug_uart_init diff --git a/arch/x86/lib/fsp/fsp_common.c b/arch/x86/lib/fsp/fsp_common.c index c78df94..5249455 100644 --- a/arch/x86/lib/fsp/fsp_common.c +++ b/arch/x86/lib/fsp/fsp_common.c @@ -95,8 +95,8 @@ int x86_fsp_init(void) /* * The second time we enter here, adjust the size of malloc() * pool before relocation. Given gd->malloc_base was adjusted
* after the call to board_init_f_mem() in arch/x86/cpu/start.S,
* we should fix up gd->malloc_limit here.
* after the call to board_init_f_malloc() in arch/x86/cpu/
* start.S, we should fix up gd->malloc_limit here. */ gd->malloc_limit += CONFIG_FSP_SYS_MALLOC_F_LEN; }
diff --git a/common/init/board_init.c b/common/init/board_init.c index e74b63b..8839a4a 100644 --- a/common/init/board_init.c +++ b/common/init/board_init.c @@ -29,32 +29,39 @@ __weak void arch_setup_gd(struct global_data *gd_ptr) } #endif /* !CONFIG_X86 */
-ulong board_init_f_mem(ulong top) +ulong board_init_f_gd_size(void) +{
return roundup(sizeof(struct global_data), 16);
+}
+void board_init_f_gd(struct global_data *gd_ptr) {
struct global_data *gd_ptr;
#ifndef _USE_MEMCPY int *ptr; #endif
/* Leave space for the stack we are running with now */
top -= 0x40;
top -= sizeof(struct global_data);
top = ALIGN(top, 16);
gd_ptr = (struct global_data *)top;
#ifdef _USE_MEMCPY memset(gd_ptr, '\0', sizeof(*gd)); #else for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); ) *ptr++ = 0; #endif
arch_setup_gd(gd_ptr);
This arch_setup_gd(gd_ptr) should not be deleted.
+}
+ulong board_init_f_malloc_size(void) +{ #if defined(CONFIG_SYS_MALLOC_F) && \ (!defined(CONFIG_SPL_BUILD) || !defined(CONFIG_SYS_SPL_MALLOC_START))
top -= CONFIG_SYS_MALLOC_F_LEN;
gd->malloc_base = top;
return CONFIG_SYS_MALLOC_F_LEN;
+#else
return 0;
#endif +}
return top;
+void board_init_f_malloc(ulong malloc_base) +{ +#if defined(CONFIG_SYS_MALLOC_F) && \
(!defined(CONFIG_SPL_BUILD) || !defined(CONFIG_SYS_SPL_MALLOC_START))
gd->malloc_base = malloc_base;
+#endif } diff --git a/include/common.h b/include/common.h index 09a131d..a2d81d9 100644 --- a/include/common.h +++ b/include/common.h @@ -225,32 +225,44 @@ void board_init_f(ulong); void board_init_r(gd_t *, ulong) __attribute__ ((noreturn));
/**
- board_init_f_mem() - Allocate global data and set stack position
- board_init_f_gd_size() - Return the size of the global data
- This function is called by each architecture very early in the start-up
- code to set up the environment for board_init_f(). It allocates space for
- global_data (see include/asm-generic/global_data.h) and places the stack
- below this.
- code to allow the C runtime to reserve space for the GD on the stack.
- This function requires a stack[1] Normally this is at @top. The function
- starts allocating space from 64 bytes below @top. First it creates space
- for global_data. Then it calls arch_setup_gd() which sets gd to point to
- the global_data space and can reserve additional bytes of space if
- required). Finally it allocates early malloc() memory
- (CONFIG_SYS_MALLOC_F_LEN). The new top of the stack is just below this,
- and it returned by this function.
- @return: GD size
- */
+ulong board_init_f_gd_size(void);
+/**
- board_init_f_gd() - Initialize (zero) the global data
- This function is called once the C runtime has allocated the GD on
- the stack. It must initialize the GD.
- @gd_ptr: the pointer to the GD to initialize
- */
+void board_init_f_gd(struct global_data *gd_ptr);
+/**
- board_init_f_malloc_size() - Return the size of the malloc arena
- This function is called once the GD is initialized, to allow the C
- runtime to allocate the malloc arena on the stack.
- @return: Malloc arena size
- */
+ulong board_init_f_malloc_size(void);
+/**
- board_init_f_malloc() - Mark the malloc arena base in the global data
- [1] Strictly speaking it would be possible to implement this function
- in C on many archs such that it does not require a stack. However this
- does not seem hugely important as only 64 byte are wasted. The 64 bytes
- are used to handle the calling standard which generally requires pushing
- addresses or registers onto the stack. We should be able to get away with
- less if this becomes important.
- This function is called once the malloc arena is allocated on the
- stack. It marks the malloc arena base in the global data.
- @top: Top of available memory, also normally the top of the stack
- @return: New stack location
*/
- @malloc_base: the base of the malloc arena
-ulong board_init_f_mem(ulong top); +void board_init_f_malloc(ulong malloc_base);
/**
- arch_setup_gd() - Set up the global_data pointer
--
Regards, Bin

Hello Bin,
On Fri, 13 Nov 2015 17:08:22 +0800, Bin Meng bmeng.cn@gmail.com wrote:
Hi Albert,
subl %esp, %eax
I guess you are confused by the AT&T assembly syntax. This should be: subl %eax, %esp.
subl %esp, %eax
Ditto.
Thanks -- last time I touched Intel assembly was more than a decade ago...
arch_setup_gd(gd_ptr);
This arch_setup_gd(gd_ptr) should not be deleted.
Correct.
Regards, Bin
Thanks! These fixes will go in v3.
Amicalement,
participants (3)
-
Albert ARIBAUD
-
Bin Meng
-
Thomas Chou