u-boot/board/raspberrypi/rpi_b/rpi_b.c
Stephen Warren 3f397782ae ARM: rpi_b: use bcm2835 mbox driver to get memory size
The firmware running on the bcm2835 SoC's VideoCore CPU determines how
much of the system RAM is available for use by the ARM CPU. Previously,
U-Boot assumed that only 128MB was available, since this was the
smallest value configured by any public firmware. However, we can now
query the actual value at run-time from the firmware using the mbox
property protocol.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
2013-03-20 15:29:29 +01:00

53 lines
1.2 KiB
C

/*
* (C) Copyright 2012 Stephen Warren
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <common.h>
#include <asm/arch/mbox.h>
#include <asm/global_data.h>
DECLARE_GLOBAL_DATA_PTR;
struct msg_get_arm_mem {
struct bcm2835_mbox_hdr hdr;
struct bcm2835_mbox_tag_get_arm_mem get_arm_mem;
u32 end_tag;
};
int dram_init(void)
{
ALLOC_ALIGN_BUFFER(struct msg_get_arm_mem, msg, 1, 16);
int ret;
BCM2835_MBOX_INIT_HDR(msg);
BCM2835_MBOX_INIT_TAG(&msg->get_arm_mem, GET_ARM_MEMORY);
ret = bcm2835_mbox_call_prop(BCM2835_MBOX_PROP_CHAN, &msg->hdr);
if (ret) {
printf("bcm2835: Could not query ARM memory size\n");
return -1;
}
gd->ram_size = msg->get_arm_mem.body.resp.mem_size;
return 0;
}
int board_init(void)
{
gd->bd->bi_boot_params = 0x100;
return 0;
}