The board really has 256M. However, the VC (VideoCore co-processor) shares the RAM, and uses a configurable portion at the top. We tell U-Boot that a smaller amount of RAM is present in order to avoid stomping on the area the VC uses.
Extracted from work by Oleksandr Tymoshenko gonzo@bluezbox.com.
Signed-off-by: Stephen Warren swarren@wwwdotorg.org --- board/raspberrypi/rpi_b/rpi_b.c | 2 +- include/configs/rpi_b.h | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/board/raspberrypi/rpi_b/rpi_b.c b/board/raspberrypi/rpi_b/rpi_b.c index 26df74b..688b0aa 100644 --- a/board/raspberrypi/rpi_b/rpi_b.c +++ b/board/raspberrypi/rpi_b/rpi_b.c @@ -21,7 +21,7 @@ DECLARE_GLOBAL_DATA_PTR;
int dram_init(void) { - gd->ram_size = SZ_256M; + gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
return 0; } diff --git a/include/configs/rpi_b.h b/include/configs/rpi_b.h index b9595f9..9f74731 100644 --- a/include/configs/rpi_b.h +++ b/include/configs/rpi_b.h @@ -36,6 +36,13 @@ #define CONFIG_NR_DRAM_BANKS 1 #define CONFIG_SYS_TEXT_BASE 0x00008000 #define CONFIG_SYS_SDRAM_BASE 0x00000000 +/* + * The board really has 256M. However, the VC (VideoCore co-processor) shares + * the RAM, and uses a configurable portion at the top. We tell U-Boot that a + * smaller amount of RAM is present in order to avoid stomping on the area + * the VC uses. + */ +#define CONFIG_SYS_SDRAM_SIZE SZ_128M #define CONFIG_SYS_UBOOT_BASE CONFIG_SYS_TEXT_BASE #define CONFIG_SYS_INIT_RAM_SIZE SZ_4K #define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_SDRAM_BASE + \