As the name may be confusing, the CONFIG_SYS_MEM_TOP_HIDE reserves some memory from the end of ram, tracked by gd->ram_size. It is not always the top of u-boot visible memory. Rewrite the macro with a weak function to provide flexibility for complex calcuation. Legacy use of this macro is still supported.
Signed-off-by: York Sun yorksun@freescale.com
---
Changes in v5: Separated as a new patch
Changes in v4: None Changes in v3: None Changes in v2: None
README | 2 +- common/board_f.c | 23 +++++++++++++++-------- 2 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/README b/README index 6ea1af2..4aa2aae 100644 --- a/README +++ b/README @@ -3877,7 +3877,7 @@ Configuration Settings: the RAM base is not zero, or RAM is divided into banks, this variable needs to be recalcuated to get the address.
-- CONFIG_SYS_MEM_TOP_HIDE (PPC only): +- CONFIG_SYS_MEM_TOP_HIDE: If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header, this specified memory area will get subtracted from the top (end) of RAM and won't get "touched" at all by U-Boot. By diff --git a/common/board_f.c b/common/board_f.c index e13657f..51d8814 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -317,6 +317,15 @@ __weak ulong board_get_usable_ram_top(ulong total_size) return gd->ram_top; }
+__weak phys_size_t board_reserve_ram_top(phys_size_t ram_size) +{ +#ifdef CONFIG_SYS_MEM_TOP_HIDE + return ram_size - CONFIG_SYS_MEM_TOP_HIDE; +#else + return ram_size; +#endif +} + static int setup_dest_addr(void) { debug("Monitor len: %08lX\n", gd->mon_len); @@ -333,19 +342,17 @@ static int setup_dest_addr(void) */ gd->secure_ram = gd->ram_size; #endif -#if defined(CONFIG_SYS_MEM_TOP_HIDE) /* * Subtract specified amount of memory to hide so that it won't * get "touched" at all by U-Boot. By fixing up gd->ram_size * the Linux kernel should now get passed the now "corrected" - * memory size and won't touch it either. This should work - * for arch/ppc and arch/powerpc. Only Linux board ports in - * arch/powerpc with bootwrapper support, that recalculate the - * memory size from the SDRAM controller setup will have to - * get fixed. + * memory size and won't touch it either. This has been used + * by arch/powerpc exclusively. Now ARMv8 takes advantage of + * thie mechanism. If memory is split into banks, addresses + * need to be calculated. */ - gd->ram_size -= CONFIG_SYS_MEM_TOP_HIDE; -#endif + gd->ram_size = board_reserve_ram_top(gd->ram_size); + #ifdef CONFIG_SYS_SDRAM_BASE gd->ram_top = CONFIG_SYS_SDRAM_BASE; #endif