u-boot/common/init/board_init.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Code shared between SPL and U-Boot proper
*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#include <common.h>
#include <bootstage.h>
#include <init.h>
#include <asm/global_data.h>
DECLARE_GLOBAL_DATA_PTR;
/* Unfortunately x86 or ARM can't compile this code as gd cannot be assigned */
#if !defined(CONFIG_X86) && !defined(CONFIG_ARM)
__weak void arch_setup_gd(struct global_data *gd_ptr)
{
gd = gd_ptr;
}
#endif /* !CONFIG_X86 && !CONFIG_ARM */
/**
* This function is called from board_init_f_init_reserve to set up
* gd->start_addr_sp for stack protection if not already set otherwise
*/
__weak void board_init_f_init_stack_protection_addr(ulong base)
{
#if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
/* set up stack pointer for stack usage if not set yet */
if (!gd->start_addr_sp)
gd->start_addr_sp = base;
#endif
}
/**
* This function is called after the position of the initial stack is
* determined in gd->start_addr_sp. Boards can override it to set up
* stack-checking markers.
*/
__weak void board_init_f_init_stack_protection(void)
{
#if CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE)
ulong stack_bottom = gd->start_addr_sp -
CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK);
/* substact some safety margin (0x20) since stack is in use here */
memset((void *)stack_bottom, CONFIG_VAL(SYS_STACK_F_CHECK_BYTE),
CONFIG_VAL(SIZE_LIMIT_PROVIDE_STACK) - 0x20);
#endif
}
/*
* Allocate reserved space for use as 'globals' from 'top' address and
* return 'bottom' address of allocated space
*
* Notes:
*
* Actual reservation cannot be done from within this function as
* it requires altering the C stack pointer, so this will be done by
* the caller upon return from this function.
*
* IMPORTANT:
*
* Alignment constraints may differ for each 'chunk' allocated. For now:
*
* - GD is aligned down on a 16-byte boundary
*
* - the early malloc arena is not aligned, therefore it follows the stack
* alignment constraint of the architecture for which we are bulding.
*
* - GD is allocated last, so that the return value of this functions is
* both the bottom of the reserved area and the address of GD, should
* the calling context need it.
*/
ulong board_init_f_alloc_reserve(ulong top)
{
/* Reserve early malloc arena */
#if CONFIG_VAL(SYS_MALLOC_F_LEN)
top -= CONFIG_VAL(SYS_MALLOC_F_LEN);
#endif
/* LAST : reserve GD (rounded up to a multiple of 16 bytes) */
top = rounddown(top-sizeof(struct global_data), 16);
return top;
}
/*
* Initialize reserved space (which has been safely allocated on the C
* stack from the C runtime environment handling code).
*
* Notes:
*
* Actual reservation was done by the caller; the locations from base
* to base+size-1 (where 'size' is the value returned by the allocation
* function above) can be accessed freely without risk of corrupting the
* C runtime environment.
*
* IMPORTANT:
*
* Upon return from the allocation function above, on some architectures
* the caller will set gd to the lowest reserved location. Therefore, in
* this initialization function, the global data MUST be placed at base.
*
* ALSO IMPORTANT:
*
* On some architectures, gd will already be good when entering this
* function. On others, it will only be good once arch_setup_gd() returns.
* Therefore, global data accesses must be done:
*
* - through gd_ptr if before the call to arch_setup_gd();
*
* - through gd once arch_setup_gd() has been called.
*
* Do not use 'gd->' until arch_setup_gd() has been called!
*
* IMPORTANT TOO:
*
* Initialization for each "chunk" (GD, early malloc arena...) ends with
* an incrementation line of the form 'base += <some size>'. The last of
* these incrementations seems useless, as base will not be used any
* more after this incrementation; but if/when a new "chunk" is appended,
* this increment will be essential as it will give base right value for
* this new chunk (which will have to end with its own incrementation
* statement). Besides, the compiler's optimizer will silently detect
* and remove the last base incrementation, therefore leaving that last
* (seemingly useless) incrementation causes no code increase.
*/
void board_init_f_init_reserve(ulong base)
{
struct global_data *gd_ptr;
/*
* clear GD entirely and set it up.
* Use gd_ptr, as gd may not be properly set yet.
*/
gd_ptr = (struct global_data *)base;
/* zero the area */
memset(gd_ptr, '\0', sizeof(*gd));
/* set GD unless architecture did it already */
#if !defined(CONFIG_ARM)
arch_setup_gd(gd_ptr);
#endif
if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
board_init_f_init_stack_protection_addr(base);
/* next alloc will be higher by one GD plus 16-byte alignment */
base += roundup(sizeof(struct global_data), 16);
/*
* record early malloc arena start.
* Use gd as it is now properly set for all architectures.
*/
#if CONFIG_VAL(SYS_MALLOC_F_LEN)
/* go down one 'early malloc arena' */
gd->malloc_base = base;
#endif
if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))
board_init_f_init_stack_protection();
}
#if CONFIG_IS_ENABLED(BOOTSTAGE)
/*
* Board-specific Platform code can reimplement show_boot_progress () if needed
*/
__weak void show_boot_progress(int val) {}
#endif