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rpi: Fix DRAM size reporting to show total RAM

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The VideoCore mailbox GET_ARM_MEMORY only reports the size of the
first accessible memory region (~947 MiB on RPi4 with 8GB), not the
total RAM. This causes U-Boot to display "DRAM: 947 MiB (total 7.9 GiB)"
instead of "DRAM: 7.9 GiB".

On Raspberry Pi 4 with 8GB RAM, the memory is split across multiple
non-contiguous banks. The dram_init() function only sets gd->ram_size
to the first bank size reported by the VideoCore firmware, while
fdtdec_setup_memory_banksize() correctly populates all memory banks
from the device tree.

Fix this by updating gd->ram_size after dram_init_banksize() has
populated all memory banks, so it reflects the actual total RAM
across all banks.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>
This commit is contained in:
Anders Roxell
2025-11-25 11:23:58 +01:00
committed by Peter Robinson
parent 15c719174c
commit 5b702cf4d0
1 changed files with 15 additions and 1 deletions
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16
board/raspberrypi/rpi/rpi.c
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@@ -334,13 +334,27 @@ int dram_init(void)
#ifdef CONFIG_OF_BOARD
int dram_init_banksize(void)
{
phys_addr_t total_size = 0;
int i;
int ret;
ret = fdtdec_setup_memory_banksize();
if (ret)
return ret;
return fdtdec_setup_mem_size_base();
ret = fdtdec_setup_mem_size_base();
if (ret)
return ret;
/* Update gd->ram_size to reflect total RAM across all banks */
for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
if (gd->bd->bi_dram[i].size == 0)
break;
total_size += gd->bd->bi_dram[i].size;
}
gd->ram_size = total_size;
return 0;
}
#endif