I have a beagle bone which has 256Mb of memory which has the dtb file.
memory{
device_type = "memory";
reg = <0x80000000 0x10000000>;
};
I expect the following change to reduce the available physical memory by 1Mb which i plan to access using io_pfn_page_range() in my driver.
memory{
device_type = "memory";
reg = <0x80000000 0x0FF00000>;
};
But even after the change the /proc/meminfo does not reflect the change. Am i missing something. Thanks in advance.
Rakesh
The bootargs passed through uEnv.txt using mem=255M does the required change. The dtb change is not respected though.
devices-tree(dts) changes will be over written by uboot
Option1:
Add mem=255M , in bootargs
Eg: setenv bootargs 'root=/dev/ram rw console=ttyS0,115200 mem=255M
Option2:
setenv bootm_size 0xFF00000
Related
I have an embedded Linux system (i.e just Busybox) with a framebuffer (/dev/fb0) and a serial port (/dev/hvc0).
The serial port is the only method of console input currently.
My Kernel has;
CONFIG_FB=y
CONFIG_FB_SIMPLE=y
CONFIG_VGA_CONSOLE=y
CONFIG_DUMMY_CONSOLE=y
CONFIG_DUMMY_CONSOLE_COLUMNS=80
CONFIG_DUMMY_CONSOLE_ROWS=25
CONFIG_FRAMEBUFFER_CONSOLE=y
CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
My bootargs are currently;
bootargs = "console=hvc0 earlycon=sbi debug";
What I would like to do is use the frame-buffer to display the console output (login terminal, printk output), but with input coming from the serial port (/dev/hvc0).
Can you be more specific regarding the Hw and the OS and u-boot?
You need something like this:
setenv bootargs console=ttyO2,115200n8 vram=16M root=/dev/ram0 rw ramdisk_size=16384 initrd=0x83000000,16M rootfstype=ext2
or this:
setenv bootargs 'console=ttymxc0,115200 root=/dev/mmcblk2p1 rootwait rw video=mxcfb0:dev=hdmi,1920x1080M#60,if=RGB24'
You see, you need to specify the tty = serial port configuration (speed, parity and so on). Also the type of file system ext2, ext4, ... the above are just examples and you need to base yours according to your system.
I am compiling my own kernel and bootloader (U-boot). I added a bunch of new environmental variables, but U-boot doesn't load anymore (it just doesn't load anything from the memory). I am using pocketbeagle and booting from an SD card. Thus I am editing the file "am335x_evm.h" found in /include/configs/.
I am trying to allocate U-boot in a way that it has more space for the environmental variables and that it can load succesfully from the memory, but I have been unable to do so. As far as I understand, by default it allocates 128kb of memory to U-boot env variables. Since I added a bunch of them, I am trying to increase its size from 128kb to 512kb.
I have changed the following line (from 128kb to 512kb):
#define CONFIG_ENV_SIZE (512 << 10)
(By the way, anyone knows why it is shifted to the left 10 bits?)
I have also changed CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND to:
#define CONFIG_ENV_OFFSET (1152 << 10) /* Originally 768 KiB in */
#define CONFIG_ENV_OFFSET_REDUND (1664 << 10) /* Originally 896 KiB in */
Then after compiling the new U-boot, I format the SD card and insert the new kernel and U-boot.
I start by erasing partitions:
export DISK=/dev/mmcblk0
sudo dd if=/dev/zero of=${DISK} bs=1M count=10
Then I transfer U-boot by doing:
sudo dd if=./u-boot/MLO of=${DISK} count=1 seek=1 bs=512k
sudo dd if=./u-boot/u-boot.img of=${DISK} count=2 seek=1 bs=576k
I then create the partition layout by doing:
sudo sfdisk ${DISK} <<-__EOF__
4M,,L,*
__EOF__
Then I add the kernel, binary trees, kernel modules, etc... When trying to boot and reading the serial port, I get nothing at all. U-boot is not able to load anything from the SD card. What am I doing wrong? I'd appreciate if you could point me what my problem is and exactly what I should be doing to increase the size and allocate everything correctly.
Depending on a few configurations I tried in /etc/fw_env.config such as one or two entries, I got the following errors when trying to read the U-boot environment variables:
root#varsomam33:~# fw_printenv serverip
Warning: Bad CRC, using default environment
or
root#varsomam33:~# fw_printenv serverip
Cannot read bad block mark: Invalid argument
According to this tutorial (https://developer.ridgerun.com/wiki/index.php/Setting_up_fw_printenv_to_modify_u-boot_environment_variables), I constructed my /etc/fw_env.config to look like this:
# MTD device name Device offset Env. size Flash sector size Number of sectors
/dev/mtd6 0x1C0000 0x20000 0x20000 1
/dev/mtd7 0x1E0000 0x20000 0x20000 1
FYI I'm using a TI Omap ARM chip (var-som-am33) with Yocto Fido default out-of-box from Variscite with these software versions:
U-boot version: u-boot-var-som-am33 2014-+gitrAUTOINC+adf9a14020
U-boot-fw-utils version: u-boot-fw-utils v2014.07+gitAUTOINC+524123a707-r0-arago0-var
The main problem is that "Device offset" is incorrectly described in the RidgeRun tutorial. It is not the absolute offset in NAND flash, but rather the offset from the partition which should be "0x0" in my case.
Here is my working /etc/fw_env.config
root#varsomam33:~# cat /etc/fw_env.config
# MTD device name Device offset Env. size Flash sector size Number of sectors
/dev/mtd6 0x0 0x20000 0x20000 1
/dev/mtd7 0x0 0x20000 0x20000 1
Further, the CRC error I was getting is thrown when there is not a U-boot backup (redundant) environment described in the /etc/fw_env.config file. The fw_printenv utility works by copying the "selected" environment, modifying the variable you have changed, and writing it out to the "new" environment. Then it swaps "selected" and "new".
So if you only have one environment in /etc/fw_env.config, it uses default values for the "selected" environment.
Here is the code tools/env/fw_env.c
1230 crc0_ok = (crc0 == *environment.crc);
1231 if (!HaveRedundEnv) {
1232 if (!crc0_ok) {
1233 fprintf (stderr,
1234 "Warning: Bad CRC, using default environment\n");
1235 memcpy(environment.data, default_environment, sizeof default_environment);
I have a series of questions on how U-boot works on the BeagleBone Black. Everything started with this tutorial on how to use a micro SD card(uSD) as extra storage.
uSD as extra storage on BBB.
Currently my setup looks like this.
$ fdisk -l
Disk /dev/mmcblk0: 7948 MB, 7948206080 bytes #uSD
Device Boot Start End Blocks Id System
/dev/mmcblk0p1 2048 198655 98304 e W95 FAT16 (LBA)
/dev/mmcblk0p2 198656 15523839 7662592 83 Linux
Disk /dev/mmcbk1: 3867 MB, 3867148288 bytes #eMMC
Device Boot Start End Blocks Id System
/dev/mmcblk1p1 * 2048 198655 98304 e W95 FAT16 (LBA)
/dev/mmcblk1p2 198656 7553023 3677184 83 Linux
So if I havent had it wrong this is what happends.
Boot sequence.
1.The BBB is powered.
2.The U-boot is loaded from the eMMC(/dev/mmcblk1p1)
3.The U-boot searches for uEnv.txt file within the uSD(/dev/mmcblk0p1) and loads it.
...... We will retake from here.
In /dev/mmcblk0p1 i have a uEnv.txt file that looks like this.
mmcdev=1
bootpart=1:2
mmcroot=/dev/mmcblk1p2 ro
optargs=quiet
In /dev/mmcblk1p1 i have the default uEnv.txt file that at some point have this lines.
loadkernel=load mmc ${mmcdev}:${mmcpart} ${loadaddr} ${kernel_file}
loadinitrd=load mmc ${mmcdev}:${mmcpart} ${initrd_addr} ${initrd_file}; setenv initrd_size ${filesize}
.......
mmcargs=setenv bootargs console=tty0 console=${console} ${optargs} ${kms_force_mode} root=${mmcroot} rootfstype=${mmcrootfstype} ${systemd}
We can see how ${mmcdev}, ${mmcroot}, ${optargs} are used although they arent defined in the file, they are defined uSD uEnv.txt.
Question 1.
¿Does this mean that both uEnv.txt files are loaded?
Retaking the boot sequence.
Boot sequence.
4.The U-boot searches for uEnv.txt file within the eMMC(/dev/mmcblk1p1) and loads it.
5.The Linux kernel is loaded.
When there is no uSD the ${mmcdev}, ${mmcroot}, ${optargs} arguments aren't defined, not in the uEnv.txt at least.
Question 2.
¿Where do the default values come?
Now the part that really bothers me. On another board a have a eMMC uEnv.txt file that looks like this.
optargs=quiet drm.debug=7 capemgr.enable_partno=BB-UART2,BB-UART1
The board boots fine without uSD.
Question 3.
How is that even posible?
The answer to the question should be in your board configuration file. Specifically the definition of 'CONFIG_EXTRA_ENV_SETTINGS'- "Define this to contain any number of null terminated strings (variable = value pairs) that will be part of the default environment compiled into the boot image." (from u-boot README file)
I am trying to get my own build of U-Boot to boot Linux on a Jetson TK1 board. As we are pushing for verified boot I am using the Flat Image Tree (unifying kernel image, device tree blob, ...) to describe my system. U-Boot can load the ITB file and tries to start the kernel but the system hangs after this message.
I assume that this is because no boot arguments are passed to the kernel (the original startup adds loads of arguments) but I am a little dumbfounded on how to pass the arguments to the kernel. I tried setting the bootargs environment variable but this did not change the situation.
How do I pass kernel arguments to the kernel when using an ITB file?
Command line arguments (taken from the APPEND command of the examples extlinux.conf):
console=ttyS0,115200n8 console=tty1 no_console_suspend=1
lp0_vec=2064#0xf46ff000 video=tegrafb mem=1862M#2048M memtype=255 ddr_die=2048M#2048M
section=256M pmuboard=0x0177:0x0000:0x02:0x43:0x00 vpr=151M#3945M tsec=32M#3913M
otf_key=c75e5bb91eb3bd947560357b64422f85 usbcore.old_scheme_first=1 core_edp_mv=1150
core_edp_ma=4000 tegraid=40.1.1.0.0 debug_uartport=lsport,3 power_supply=Adapter
audio_codec=rt5640 modem_id=0 android.kerneltype=normal usb_port_owner_info=0
fbcon=map:1 commchip_id=0 usb_port_owner_info=0 lane_owner_info=6 emc_max_dvfs=0
touch_id=0#0 tegra_fbmem=32899072#0xad012000 board_info=0x0177:0x0000:0x02:0x43:0x00
root=/dev/mmcblk0p1 rw rootwait tegraboot=sdmmc gpt
Content of ITS file:
/dts-v1/;
/ {
description = "Simple image with single Linux kernel and FDT blob";
#address-cells = <1>;
images {
kernel#1 {
description = "Vanilla Linux kernel";
data = /incbin/("./zImage");
type = "kernel";
arch = "arm";
os = "linux";
compression = "none";
load = <0x81008000>;
entry = <0x81008000>;
hash#1 {
algo = "crc32";
};
hash#2 {
algo = "sha1";
};
};
fdt#1 {
description = "Flattened Device Tree blob";
data = /incbin/("./tegra124-pm375.dtb");
type = "flat_dt";
arch = "arm";
compression = "none";
hash#1 {
algo = "crc32";
};
hash#2 {
algo = "sha1";
};
};
};
configurations {
default = "conf#1";
conf#1 {
description = "Boot Linux kernel with FDT blob";
kernel = "kernel#1";
fdt = "fdt#1";
};
};
};
U-Boot Output:
Tegra124 (Jetson TK1) # fatload mmc 1 0x90000000 /kernel_fdt.itb
reading /kernel_fdt.itb
5946200 bytes read in 497 ms (11.4 MiB/s)
Tegra124 (Jetson TK1) # bootm 0x90000000
## Loading kernel from FIT Image at 90000000 ...
Using 'conf#1' configuration
Verifying Hash Integrity ... OK
Trying 'kernel#1' kernel subimage
Description: Vanilla Linux kernel
Type: Kernel Image
Compression: uncompressed
Data Start: 0x900000ec
Data Size: 5910168 Bytes = 5.6 MiB
Architecture: ARM
OS: Linux
Load Address: 0x00000000
Entry Point: 0x00000000
Hash algo: crc32
Hash value: c5b4b377
Hash algo: sha1
Hash value: f001007efe83f563425bfe0659186a32395c946c
Verifying Hash Integrity ... crc32+ sha1+ OK
## Loading fdt from FIT Image at 90000000 ...
Using 'conf#1' configuration
Trying 'fdt#1' fdt subimage
Description: Flattened Device Tree blob
Type: Flat Device Tree
Compression: uncompressed
Data Start: 0x905a30ac
Data Size: 34678 Bytes = 33.9 KiB
Architecture: ARM
Hash algo: crc32
Hash value: e466b23e
Hash algo: sha1
Hash value: ec909ae16e62233d0ed1e1f4c909085abc9b5879
Verifying Hash Integrity ... crc32+ sha1+ OK
Booting using the fdt blob at 0x905a30ac
Loading Kernel Image ... OK
Using Device Tree in place at 905a30ac, end 905ae821
Starting kernel ...
The salient issue is that the system seems to hang after U-Boot outputs the text
Starting kernel ...
If an uncompressed kernel Image file has been loaded, then the actual kernel startup code would be executed next.
But if a uImage or zImage file has been loaded (which are also reported as "uncompressed" because they are self-extracting), then the next code executed would be the decompression routine that is attached to the zImage file. Normally this decompression routine will output text such as
Uncompressing Linux............ done, booting the kernel.
before the actual kernel startup code would be executed, before any processing of the kernel command line, before any processing of the Device Tree blob, and prior to any console output from the kernel (including earlyprintk).
There's a discrepancy between the kernel load & start addresses specified in the image header
Load Address: 0x00000000
Entry Point: 0x00000000
versus what is specified in the DT:
load = <0x81008000>;
entry = <0x81008000>;
Since the kernel image is temporarily loaded at
## Loading kernel from FIT Image at 90000000 ...
the addresses in the DT would seem to be correct, and the addresses in the image header are bogus.
Assuming that there is no physical RAM at 0x00000000, the result will be that the kernel image is copied (or decompressed) to the bogus load address of 0, and then the kernel image will be executed by branching to the bogus entry point of 0. The CPU is likely to hang trying to execute garbage from nonexistent memory, and that correlates perfectly with what you report.
Solution is (1) confirm that the kernel is linked to the correct address and (2) to specify the correct addresses in the mkimage command using the -a and -e command options.
This correction should at least get you past this one point.
When using device tree, you still use bootargs to provide arguments.
Check that:
You have compiled the tree (using compiler scripts/dtc/dtc inside the Linux kernel)
Support for device tree is enabled in the kernel config (symbol CONFIG_USE_OF) (where OF stands for "Open Firmware")
You provided U-Boot the address of the tree: bootm <uImage address> - <dtb address>
Serial console is enabled in the kernel config under Device Drivers -> Character Devices -> Serial Drivers
Console is enabled in bootargs (e.g., console=ttyS0,115200)
I experienced the same or similar issue. My solution (or work around) for this issue was to set the U-Boot environment variables initrd_high and fdt_high to an address in RAM before the relocated U-boot (in my case 8effffff).