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doc: description of board_get_usable_ram_top()

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Improve the description of function board_get_usable_ram_top().

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Heinrich Schuchardt 2023-08-14 08:44:26 +02:00
parent 78246baa8d
commit 289bd72ea4
1 changed files with 10 additions and 5 deletions
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15
include/init.h
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@ -296,13 +296,18 @@ int checkboard(void);
int show_board_info(void);
/**
* Get the uppermost pointer that is valid to access
* board_get_usable_ram_top() - get uppermost address for U-Boot relocation
*
* Some systems may not map all of their address space. This function allows
* boards to indicate what their highest support pointer value is for DRAM
* access.
* Some systems have reserved memory areas in high memory. By implementing this
* function boards can indicate the highest address value to be used when
* relocating U-Boot. The returned address is exclusive (i.e. 1 byte above the
* last usable address).
*
* @param total_size Size of U-Boot (unused?)
* Due to overflow on systems with 32bit phys_addr_t a value 0 is used instead
* of 4GiB.
*
* @total_size: monitor length in bytes (size of U-Boot code)
* Return: uppermost address for U-Boot relocation
*/
phys_size_t board_get_usable_ram_top(phys_size_t total_size);