u-boot-brain/include/configs/rpi-common.h
Stephen Warren f031f501ef rpi: BCM2837 and Raspberry Pi 3 32-bit support
The Raspberry Pi 3 contains a BCM2837 SoC. The BCM2837 is a BCM2836 with
the CPU complex swapped out for a quad-core ARMv8. This can operate in 32-
or 64-bit mode. 32-bit mode is the current default selected by the
VideoCore firmware on the Raspberry Pi 3. This patch adds a 32-bit port of
U-Boot for the Raspberry Pi 3.

>From U-Boot's perspective, the only delta between the RPi 2 and RPi 3 is a
change in usage of the SoC UARTs. On all previous Pis, the PL011 was the
only UART in use. The Raspberry Pi 3 adds a Bluetooth module which uses a
UART to connect to the SoC. By default, the PL011 is used for this purpose
since it has larger FIFOs than the other "mini" UART. However, this can
be configured via the VideoCore firmware's config.txt file. This patch
hard-codes use of the mini UART in the RPi 3 port. If your system uses the
PL011 UART for the console even on the RPi 3, please use the RPi 2 U-Boot
port instead. A future change might determine which UART to use at
run-time, thus allowing the RPi 2 and RPi 3 (32-bit) ports to be squashed
together.

The mini UART has some limitations. One externally visible issue in the
BCM2837 integration is that the UART divides the SoC's "core clock" to
generate the baud rate. The core clock is typically variable, and under
control of the VideoCore firmware for thermal management reasons. If the
VC FW does modify the core clock rate, UART communication will be
corrupted since the baud rate will vary from the expected value. This was
not an issue for the PL011 UART, since it is fed by a fixed 3MHz clock. To
work around this, the VideoCore firmware can be told not to modify the SoC
core clock. However, the only way this can happen and be thermally safe is
to limit the core clock to a low/minimum frequency. This leaves
performance on the table for use-cases that don't care about a UART
console. Consequently, use of the mini UART console must be explicitly
requested by entering the following line into config.txt:

    enable_uart=1

A recent version of the VC firmware is required to ensure that the mini
UART is fully and correctly initialized by the VC FW; at least
firmware.git 046effa13ebc "firmware: arm_loader: emmc clock depends on
core clock See: https://github.com/raspberrypi/firmware/issues/572".

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2016-04-01 17:17:42 -04:00

203 lines
6.0 KiB
C

/*
* (C) Copyright 2012-2016 Stephen Warren
*
* SPDX-License-Identifier: GPL-2.0
*/
#ifndef _RPI_COMMON_H_
#define _RPI_COMMON_H_
#include <linux/sizes.h>
#include <asm/arch/timer.h>
/* Architecture, CPU, etc.*/
#define CONFIG_ARCH_CPU_INIT
#define CONFIG_SYS_TIMER_RATE 1000000
#define CONFIG_SYS_TIMER_COUNTER \
(&((struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR)->clo)
/*
* 2835 is a SKU in a series for which the 2708 is the first or primary SoC,
* so 2708 has historically been used rather than a dedicated 2835 ID.
*
* We don't define a machine type for bcm2709/bcm2836 since the RPi Foundation
* chose to use someone else's previously registered machine ID (3139, MX51_GGC)
* rather than obtaining a valid ID:-/
*
* For the bcm2837, hopefully a machine type is not needed, since everything
* is DT.
*/
#ifdef CONFIG_BCM2835
#define CONFIG_MACH_TYPE MACH_TYPE_BCM2708
#endif
/* Memory layout */
#define CONFIG_NR_DRAM_BANKS 1
#define CONFIG_SYS_SDRAM_BASE 0x00000000
#define CONFIG_SYS_TEXT_BASE 0x00008000
#define CONFIG_SYS_UBOOT_BASE CONFIG_SYS_TEXT_BASE
/*
* 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_INIT_SP_ADDR (CONFIG_SYS_SDRAM_BASE + \
CONFIG_SYS_SDRAM_SIZE - \
GENERATED_GBL_DATA_SIZE)
#define CONFIG_SYS_MALLOC_LEN SZ_4M
#define CONFIG_SYS_MEMTEST_START 0x00100000
#define CONFIG_SYS_MEMTEST_END 0x00200000
#define CONFIG_LOADADDR 0x00200000
/* Flash */
#define CONFIG_SYS_NO_FLASH
/* Devices */
/* GPIO */
#define CONFIG_BCM2835_GPIO
/* LCD */
#define CONFIG_LCD
#define CONFIG_LCD_DT_SIMPLEFB
#define LCD_BPP LCD_COLOR16
/*
* Prevent allocation of RAM for FB; the real FB address is queried
* dynamically from the VideoCore co-processor, and comes from RAM
* not owned by the ARM CPU.
*/
#define CONFIG_FB_ADDR 0
#define CONFIG_VIDEO_BCM2835
#define CONFIG_SYS_WHITE_ON_BLACK
#define CONFIG_CONSOLE_SCROLL_LINES 10
/* SD/MMC configuration */
#define CONFIG_GENERIC_MMC
#define CONFIG_MMC
#define CONFIG_SDHCI
#define CONFIG_MMC_SDHCI_IO_ACCESSORS
#define CONFIG_BCM2835_SDHCI
#define CONFIG_CMD_USB
#ifdef CONFIG_CMD_USB
#define CONFIG_USB_DWC2
#ifndef CONFIG_BCM2835
#define CONFIG_USB_DWC2_REG_ADDR 0x3f980000
#else
#define CONFIG_USB_DWC2_REG_ADDR 0x20980000
#endif
#define CONFIG_USB_STORAGE
#define CONFIG_USB_HOST_ETHER
#define CONFIG_USB_ETHER_SMSC95XX
#define CONFIG_MISC_INIT_R
#define CONFIG_USB_KEYBOARD
#define CONFIG_SYS_USB_EVENT_POLL
#define CONFIG_SYS_STDIO_DEREGISTER
#endif
/* Console UART */
#ifdef CONFIG_BCM2837
#define CONFIG_BCM283X_MU_SERIAL
#else
#define CONFIG_PL01X_SERIAL
#endif
#define CONFIG_CONS_INDEX 0
#define CONFIG_BAUDRATE 115200
/* Console configuration */
#define CONFIG_SYS_CBSIZE 1024
#define CONFIG_SYS_PBSIZE (CONFIG_SYS_CBSIZE + \
sizeof(CONFIG_SYS_PROMPT) + 16)
/* Environment */
#define CONFIG_ENV_SIZE SZ_16K
#define CONFIG_ENV_IS_IN_FAT
#define FAT_ENV_INTERFACE "mmc"
#define FAT_ENV_DEVICE_AND_PART "0:1"
#define FAT_ENV_FILE "uboot.env"
#define CONFIG_FAT_WRITE
#define CONFIG_ENV_VARS_UBOOT_CONFIG
#define CONFIG_SYS_LOAD_ADDR 0x1000000
#define CONFIG_CONSOLE_MUX
#define CONFIG_SYS_CONSOLE_IS_IN_ENV
#define CONFIG_PREBOOT "usb start"
/* Shell */
#define CONFIG_SYS_MAXARGS 16
#define CONFIG_COMMAND_HISTORY
/* Commands */
#define CONFIG_CMD_MMC
#define CONFIG_PARTITION_UUIDS
#define CONFIG_CMD_PART
/* ATAGs support for bootm/bootz */
#define CONFIG_SETUP_MEMORY_TAGS
#define CONFIG_CMDLINE_TAG
#define CONFIG_INITRD_TAG
#include <config_distro_defaults.h>
/* Environment */
#define CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
#define ENV_DEVICE_SETTINGS \
"stdin=serial,usbkbd\0" \
"stdout=serial,lcd\0" \
"stderr=serial,lcd\0"
/*
* Memory layout for where various images get loaded by boot scripts:
*
* I suspect address 0 is used as the SMP pen on the RPi2, so avoid this.
*
* fdt_addr_r simply shouldn't overlap anything else. However, the RPi's
* binary firmware loads a DT to address 0x100, so we choose this address to
* match it. This allows custom boot scripts to pass this DT on to Linux
* simply by not over-writing the data at this address. When using U-Boot,
* U-Boot (and scripts it executes) typicaly ignore the DT loaded by the FW
* and loads its own DT from disk (triggered by boot.scr or extlinux.conf).
*
* pxefile_addr_r can be pretty much anywhere that doesn't conflict with
* something else. Put it low in memory to avoid conflicts.
*
* kernel_addr_r must be within the first 128M of RAM in order for the
* kernel's CONFIG_AUTO_ZRELADDR option to work. Since the kernel will
* decompress itself to 0x8000 after the start of RAM, kernel_addr_r
* should not overlap that area, or the kernel will have to copy itself
* somewhere else before decompression. Similarly, the address of any other
* data passed to the kernel shouldn't overlap the start of RAM. Pushing
* this up to 16M allows for a sizable kernel to be decompressed below the
* compressed load address.
*
* scriptaddr can be pretty much anywhere that doesn't conflict with something
* else. Choosing 32M allows for the compressed kernel to be up to 16M.
*
* ramdisk_addr_r simply shouldn't overlap anything else. Choosing 33M allows
* for any boot script to be up to 1M, which is hopefully plenty.
*/
#define ENV_MEM_LAYOUT_SETTINGS \
"fdt_high=ffffffff\0" \
"initrd_high=ffffffff\0" \
"fdt_addr_r=0x00000100\0" \
"pxefile_addr_r=0x00100000\0" \
"kernel_addr_r=0x01000000\0" \
"scriptaddr=0x02000000\0" \
"ramdisk_addr_r=0x02100000\0" \
#define BOOT_TARGET_DEVICES(func) \
func(MMC, mmc, 0) \
func(USB, usb, 0) \
func(PXE, pxe, na) \
func(DHCP, dhcp, na)
#include <config_distro_bootcmd.h>
#define CONFIG_EXTRA_ENV_SETTINGS \
ENV_DEVICE_SETTINGS \
ENV_MEM_LAYOUT_SETTINGS \
BOOTENV
#define CONFIG_BOOTDELAY 2
#endif