diff options
| -rw-r--r-- | Documentation/boards/bcm2835.rst | 6 | ||||
| -rw-r--r-- | arch/arm/boards/raspberry-pi/rpi-common.c | 47 |
2 files changed, 53 insertions, 0 deletions
diff --git a/Documentation/boards/bcm2835.rst b/Documentation/boards/bcm2835.rst index 95e910896b..e9ad1d4d57 100644 --- a/Documentation/boards/bcm2835.rst +++ b/Documentation/boards/bcm2835.rst @@ -34,5 +34,11 @@ VideoCore firmware creates a device tree based on the entries in ``config.txt``. bootm -o /vc.dtb /boot/kernel7.img +VideoCore device tree also contains the kernel command-line that is constructed from ``cmdline.txt`` and other parameters internally determined by the VideoCore firmware. Normally in Barebox this command-line gets overwritten on boot by the Linux bootargs (see :ref:`booting_linux`). + +The original command-line from VideoCore device tree is available to the Barebox environment in the ``vc.bootargs`` global variable. For example, to append it to the Linux bootargs:: + + global linux.bootargs.vc="$global.vc.bootargs" + .. _Raspberry Pi firmware: https://codeload.github.com/raspberrypi/firmware/zip/80e1fbeb78f9df06701d28c0ed3a3060a3f557ef .. _documentation for config.txt: https://www.raspberrypi.org/documentation/configuration/config-txt/ diff --git a/arch/arm/boards/raspberry-pi/rpi-common.c b/arch/arm/boards/raspberry-pi/rpi-common.c index fffa882a70..9d334cde12 100644 --- a/arch/arm/boards/raspberry-pi/rpi-common.c +++ b/arch/arm/boards/raspberry-pi/rpi-common.c @@ -30,6 +30,7 @@ #include <asm/barebox-arm.h> #include <generated/mach-types.h> #include <linux/sizes.h> +#include <globalvar.h> #include <mach/core.h> #include <mach/mbox.h> @@ -375,11 +376,50 @@ static int rpi_env_init(void) return 0; } +/* Extract /chosen/bootargs from the VideoCore FDT into vc.bootargs + * global variable. */ +static int rpi_vc_fdt_bootargs(void *fdt) +{ + int ret = 0; + struct device_node *root = NULL, *node; + const char *cmdline; + + root = of_unflatten_dtb(fdt); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + root = NULL; + goto out; + } + + node = of_find_node_by_path_from(root, "/chosen"); + if (!node) { + pr_err("no /chosen node\n"); + ret = -ENOENT; + goto out; + } + + cmdline = of_get_property(node, "bootargs", NULL); + if (!cmdline) { + pr_err("no bootargs property in the /chosen node\n"); + ret = -ENOENT; + goto out; + } + + globalvar_add_simple("vc.bootargs", cmdline); + +out: + if (root) + of_delete_node(root); + + return ret; +} + static void rpi_vc_fdt(void) { void *saved_vc_fdt; struct fdt_header *oftree; unsigned long magic, size; + int ret; /* VideoCore FDT was copied in PBL just above Barebox memory */ saved_vc_fdt = (void *)(arm_mem_endmem_get()); @@ -401,6 +441,13 @@ static void rpi_vc_fdt(void) pr_err("failed to save videocore fdt to a file\n"); return; } + + ret = rpi_vc_fdt_bootargs(saved_vc_fdt); + if (ret) { + pr_err("failed to extract bootargs from videocore fdt: %d\n", + ret); + return; + } } static int rpi_devices_init(void) |