[U-Boot] [PATCH v3] Fix board init code to use a valid C runtime environment
Albert ARIBAUD
albert.u.boot at aribaud.net
Fri Nov 13 15:43:23 CET 2015
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 at aribaud.net>
---
For NIOS2, this patch contains all manual v1 and v2
fixes by Thomas.
For x86, this patch contains all manual v2 fixes by Bin.
Changes in v3:
- Rebase after commit 9ac4fc82
- Simplify malloc conditional as per commit 9ac4fc82
- Fix NIOS2 return value register (r2, not r4)
- Fix x86 subl argument inversion
- Group allocations in a single function
- Group initializations in a single function
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 | 12 +++++---
arch/arm/lib/crt0.S | 6 ++--
arch/arm/lib/crt0_64.S | 6 ++--
arch/microblaze/cpu/start.S | 4 +--
arch/nios2/cpu/start.S | 13 +++++---
arch/powerpc/cpu/ppc4xx/start.S | 14 ++++++---
arch/x86/cpu/start.S | 7 +++--
arch/x86/lib/fsp/fsp_common.c | 4 +--
common/init/board_init.c | 67 +++++++++++++++++++++++++++++++++--------
include/common.h | 33 ++++++++------------
10 files changed, 108 insertions(+), 58 deletions(-)
diff --git a/arch/arc/lib/start.S b/arch/arc/lib/start.S
index 26a5934..2a99193 100644
--- a/arch/arc/lib/start.S
+++ b/arch/arc/lib/start.S
@@ -54,14 +54,16 @@ ENTRY(_start)
mov %sp, CONFIG_SYS_INIT_SP_ADDR
mov %fp, %sp
- /* Allocate and zero GD, update SP */
- mov %r0, %sp
- bl board_init_f_mem
-
+ /* Get reserved area size, update SP and FP */
+ bl board_init_f_get_reserve_size
/* Update stack- and frame-pointers */
- mov %sp, %r0
+ sub %sp, %sp, %r0
mov %fp, %sp
+ /* Initialize reserved area */
+ mov %r0, %sp
+ bl board_init_f_init_reserve
+
/* 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..4ec89a4 100644
--- a/arch/arm/lib/crt0.S
+++ b/arch/arm/lib/crt0.S
@@ -82,9 +82,11 @@ ENTRY(_main)
#else
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
#endif
+ bl board_init_f_get_reserve_size
+ sub sp, sp, r0
+ mov r9, sp
mov r0, sp
- bl board_init_f_mem
- mov sp, r0
+ bl board_init_f_init_reserve
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..d0f8db8 100644
--- a/arch/arm/lib/crt0_64.S
+++ b/arch/arm/lib/crt0_64.S
@@ -75,8 +75,10 @@ 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_reserve_size
+ sub sp, sp, x0
+ mov x0, sp
+ bl board_init_f_init_reserve
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..c95f1f4 100644
--- a/arch/nios2/cpu/start.S
+++ b/arch/nios2/cpu/start.S
@@ -106,14 +106,17 @@ _reloc:
stw r0, 4(sp)
mov fp, sp
- /* Allocate and zero GD, update SP */
+ /* Allocate and initialize reserved area, update SP */
+ movhi r2, %hi(board_init_f_reserve_size at h)
+ ori r2, r2, %lo(board_init_f_reserve_size at h)
+ callr r2
+ sub sp, sp, r2
mov r4, sp
- movhi r2, %hi(board_init_f_mem at h)
- ori r2, r2, %lo(board_init_f_mem at h)
+ movhi r2, %hi(board_init_f_init_reserve at h)
+ ori r2, r2, %lo(board_init_f_init_reserve at h)
callr r2
- /* Update stack- and frame-pointers */
- mov sp, r2
+ /* Update frame-pointer */
mov fp, sp
/* Call board_init_f -- never returns */
diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S
index 77d4040..cc6e4ec 100644
--- a/arch/powerpc/cpu/ppc4xx/start.S
+++ b/arch/powerpc/cpu/ppc4xx/start.S
@@ -761,9 +761,10 @@ _start:
bl cpu_init_f /* run low-level CPU init code (from Flash) */
#ifdef CONFIG_SYS_GENERIC_BOARD
+ bl board_init_f_reserve_size
+ sub r1, r1, r3
mr r3, r1
- bl board_init_f_mem
- mr r1, r3
+ bl board_init_f_init_reserve
li r0,0
stwu r0, -4(r1)
stwu r0, -4(r1)
@@ -1037,9 +1038,14 @@ _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
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..b30383f 100644
--- a/arch/x86/cpu/start.S
+++ b/arch/x86/cpu/start.S
@@ -121,10 +121,11 @@ car_init_ret:
* with esi holding the HOB list address returned by the FSP.
*/
#endif
- /* Set up global data */
+ /* Reserve 'globals' on the stack */
+ call board_init_f_reserve_size
+ subl %eax, %esp
mov %esp, %eax
- call board_init_f_mem
- mov %eax, %esp
+ call board_init_f_init_reserve
#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 1c6126d..e033253 100644
--- a/common/init/board_init.c
+++ b/common/init/board_init.c
@@ -21,39 +21,80 @@ DECLARE_GLOBAL_DATA_PTR;
#define _USE_MEMCPY
#endif
-/* Unfortunately x86 can't compile this code as gd cannot be assigned */
-#ifndef CONFIG_X86
+/* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
+#if !defined(CONFIG_X86) && !defined(CONFIG_SYS_THUMB_BUILD)
__weak void arch_setup_gd(struct global_data *gd_ptr)
{
gd = gd_ptr;
}
-#endif /* !CONFIG_X86 */
+#endif /* !CONFIG_X86 && !CONFIG_SYS_THUMB_BUILD */
-ulong board_init_f_mem(ulong top)
+/*
+ * Compute size of space to reserve on stack for use as 'globals'
+ * and return size request for reserved area.
+ *
+ * Notes:
+ *
+ * Reservation cannot be actually done from within a C function
+ * as it implies modifying the C stack.
+ *
+ */
+
+ulong board_init_f_get_reserve_size(void)
+{
+ ulong size;
+
+ /* Reserve GD (rounded up to a multiple of 16 bytes) */
+ size = roundup(sizeof(struct global_data), 16);
+
+ /* Reserve malloc arena */
+#if defined(CONFIG_SYS_MALLOC_F)
+ size += CONFIG_SYS_MALLOC_F_LEN;
+#endif
+
+ return size;
+}
+
+/*
+ * Initialize reserved space (which has been safely allocated on the C
+ * stack from the C runtime environment handling code).
+ *
+ * Do not use 'gd->' until arch_setup_gd() has been called!
+ */
+
+void board_init_f_init_reserve(ulong base)
{
struct global_data *gd_ptr;
#ifndef _USE_MEMCPY
int *ptr;
#endif
- /* Leave space for the stack we are running with now */
- top -= 0x40;
+ /*
+ * clear GD entirely
+ */
- top -= sizeof(struct global_data);
- top = ALIGN(top, 16);
- gd_ptr = (struct global_data *)top;
+ gd_ptr = (struct global_data *)base;
+ /* go down one GD plus 16-byte alignment */
+ base += roundup(sizeof(struct global_data), 16);
+ /* zero the area */
#ifdef _USE_MEMCPY
memset(gd_ptr, '\0', sizeof(*gd));
#else
for (ptr = (int *)gd_ptr; ptr < (int *)(gd_ptr + 1); )
*ptr++ = 0;
#endif
+ /* set GD unless architecture did it already */
+#if !defined(CONFIG_X86) && !defined(CONFIG_SYS_THUMB_BUILD)
arch_setup_gd(gd_ptr);
+#endif
+
+ /*
+ * record malloc arena start
+ */
#if defined(CONFIG_SYS_MALLOC_F)
- top -= CONFIG_SYS_MALLOC_F_LEN;
- gd->malloc_base = top;
+ /* go down one malloc arena */
+ gd->malloc_base = base;
+ base += CONFIG_SYS_MALLOC_F_LEN;
#endif
-
- return top;
}
diff --git a/include/common.h b/include/common.h
index 09a131d..988d67a 100644
--- a/include/common.h
+++ b/include/common.h
@@ -225,32 +225,25 @@ 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
+ * ulong board_init_f_get_reserve_size - return size of reserved area
*
* 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 on the stack for writable
+ * 'globals' such as GD and the malloc arena.
*
- * 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: size of reserved area
+ */
+ulong board_init_f_get_reserve_size(void);
+
+/**
+ * board_init_f_init_reserve - initialize the reserved area(s)
*
- * [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 C runtime has allocated the reserved
+ * area on the stack. It must initialize the GD at the base of that area.
*
- * @top: Top of available memory, also normally the top of the stack
- * @return: New stack location
+ * @base: top from which reservation was done
*/
-ulong board_init_f_mem(ulong top);
+void board_init_f_init_reserve(ulong base);
/**
* arch_setup_gd() - Set up the global_data pointer
--
2.5.0
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