Status:
=======
-In general, all boards for which a configuration option exists in the
-Makefile have been tested to some extent and can be considered
+In general, all boards for which a default configuration file exists in the
+configs/ directory have been tested to some extent and can be considered
"working". In fact, many of them are used in production systems.
-In case of problems see the CHANGELOG file to find out who contributed
-the specific port. In addition, there are various MAINTAINERS files
-scattered throughout the U-Boot source identifying the people or
-companies responsible for various boards and subsystems.
+In case of problems you can use
-Note: As of August, 2010, there is no longer a CHANGELOG file in the
-actual U-Boot source tree; however, it can be created dynamically
-from the Git log using:
+ scripts/get_maintainer.pl <path>
- make CHANGELOG
+to identify the people or companies responsible for various boards and
+subsystems. Or have a look at the git log.
Where to get help:
IH_OS_U_BOOT u_boot_hush_start
-Versioning:
-===========
-
-Starting with the release in October 2008, the names of the releases
-were changed from numerical release numbers without deeper meaning
-into a time stamp based numbering. Regular releases are identified by
-names consisting of the calendar year and month of the release date.
-Additional fields (if present) indicate release candidates or bug fix
-releases in "stable" maintenance trees.
-
-Examples:
- U-Boot v2009.11 - Release November 2009
- U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
- U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
-
-
-Directory Hierarchy:
-====================
-
-/arch Architecture-specific files
- /arc Files generic to ARC architecture
- /arm Files generic to ARM architecture
- /m68k Files generic to m68k architecture
- /microblaze Files generic to microblaze architecture
- /mips Files generic to MIPS architecture
- /nios2 Files generic to Altera NIOS2 architecture
- /powerpc Files generic to PowerPC architecture
- /riscv Files generic to RISC-V architecture
- /sandbox Files generic to HW-independent "sandbox"
- /sh Files generic to SH architecture
- /x86 Files generic to x86 architecture
- /xtensa Files generic to Xtensa architecture
-/api Machine/arch-independent API for external apps
-/board Board-dependent files
-/boot Support for images and booting
-/cmd U-Boot commands functions
-/common Misc architecture-independent functions
-/configs Board default configuration files
-/disk Code for disk drive partition handling
-/doc Documentation (a mix of ReST and READMEs)
-/drivers Device drivers
-/dts Makefile for building internal U-Boot fdt.
-/env Environment support
-/examples Example code for standalone applications, etc.
-/fs Filesystem code (cramfs, ext2, jffs2, etc.)
-/include Header Files
-/lib Library routines generic to all architectures
-/Licenses Various license files
-/net Networking code
-/post Power On Self Test
-/scripts Various build scripts and Makefiles
-/test Various unit test files
-/tools Tools to build and sign FIT images, etc.
-
Software Configuration:
=======================
specific to be undertaken on a native platform. The sandbox is also used to
run some of U-Boot's tests.
-See doc/arch/sandbox.rst for more details.
+See doc/arch/sandbox/sandbox.rst for more details.
Board Initialisation Flow:
same as CFG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
it could be different for ARM SoCs.
-- MIPS CPU options:
- CONFIG_XWAY_SWAP_BYTES
-
- Enable compilation of tools/xway-swap-bytes needed for Lantiq
- XWAY SoCs for booting from NOR flash. The U-Boot image needs to
- be swapped if a flash programmer is used.
-
- ARM options:
CFG_SYS_EXCEPTION_VECTORS_HIGH
example "env grep" and "setexpr".
- Watchdog:
- CONFIG_SYS_WATCHDOG_FREQ
+ CFG_SYS_WATCHDOG_FREQ
Some platforms automatically call WATCHDOG_RESET()
from the timer interrupt handler every
- CONFIG_SYS_WATCHDOG_FREQ interrupts. If not set by the
+ CFG_SYS_WATCHDOG_FREQ interrupts. If not set by the
board configuration file, a default of CONFIG_SYS_HZ/2
- (i.e. 500) is used. Setting CONFIG_SYS_WATCHDOG_FREQ
+ (i.e. 500) is used. Setting CFG_SYS_WATCHDOG_FREQ
to 0 disables calling WATCHDOG_RESET() from the timer
interrupt.
CONFIG_LAN91C96_USE_32_BIT
Define this to enable 32 bit addressing
- CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
+ CFG_SYS_DAVINCI_EMAC_PHY_COUNT
Define this if you have more then 3 PHYs.
CONFIG_FTGMAC100
To enable the ULPI layer support, define CONFIG_USB_ULPI and
CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
If your ULPI phy needs a different reference clock than the
- standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
+ standard 24 MHz then you have to define CFG_ULPI_REF_CLK to
the appropriate value in Hz.
- MMC Support:
4th and following
BOOTP requests: delay 0 ... 8 sec
- CONFIG_BOOTP_ID_CACHE_SIZE
+ CFG_BOOTP_ID_CACHE_SIZE
BOOTP packets are uniquely identified using a 32-bit ID. The
server will copy the ID from client requests to responses and
time is too long, U-Boot will retransmit requests. In order
to allow earlier responses to still be accepted after these
retransmissions, U-Boot's BOOTP client keeps a small cache of
- IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
+ IDs. The CFG_BOOTP_ID_CACHE_SIZE controls the size of this
cache. The default is to keep IDs for up to four outstanding
requests. Increasing this will allow U-Boot to accept offers
from a BOOTP client in networks with unusually high latency.
status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
to include the gpio_led driver in the U-Boot binary.
- CONFIG_GPIO_LED_INVERTED_TABLE
+ CFG_GPIO_LED_INVERTED_TABLE
Some GPIO connected LEDs may have inverted polarity in which
case the GPIO high value corresponds to LED off state and
GPIO low value corresponds to LED on state.
- In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
+ In such cases CFG_GPIO_LED_INVERTED_TABLE may be defined
with a list of GPIO LEDs that have inverted polarity.
- I2C Support:
SPI EEPROM, also an instance works with Crystal A/D and
D/As on the SACSng board)
- CONFIG_SYS_SPI_MXC_WAIT
+ CFG_SYS_SPI_MXC_WAIT
Timeout for waiting until spi transfer completed.
default: (CONFIG_SYS_HZ/100) /* 10 ms */
If defined, a function that provides delays in the FPGA
configuration driver.
- CONFIG_SYS_FPGA_CHECK_ERROR
+ CFG_SYS_FPGA_CHECK_ERROR
Check for configuration errors during FPGA bitfile
loading. For example, abort during Virtex II
- CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
undefine this when you're short of memory.
-- CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
+- CFG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
width of the commands listed in the 'help' command output.
- CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
- CONFIG_SYS_MC_RSV_MEM_ALIGN
Define alignment of reserved memory MC requires
-Reproducible builds
--------------------
-
-In order to achieve reproducible builds, timestamps used in the U-Boot build
-process have to be set to a fixed value.
-
-This is done using the SOURCE_DATE_EPOCH environment variable.
-SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
-option for U-Boot or an environment variable in U-Boot.
-
-SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
Building the Software:
======================
base - print or set address offset
printenv- print environment variables
pwm - control pwm channels
+seama - load SEAMA NAND image
setenv - set environment variables
saveenv - save environment variables to persistent storage
protect - enable or disable FLASH write protection
[q, b, e, ?] ## Application terminated, rc = 0x0
-Minicom warning:
-================
-
-Over time, many people have reported problems when trying to use the
-"minicom" terminal emulation program for serial download. I (wd)
-consider minicom to be broken, and recommend not to use it. Under
-Unix, I recommend to use C-Kermit for general purpose use (and
-especially for kermit binary protocol download ("loadb" command), and
-use "cu" for S-Record download ("loads" command). See
-https://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
-for help with kermit.
-
-
-Nevertheless, if you absolutely want to use it try adding this
-configuration to your "File transfer protocols" section:
-
- Name Program Name U/D FullScr IO-Red. Multi
- X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
- Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
-
-
-NetBSD Notes:
-=============
-
-Starting at version 0.9.2, U-Boot supports NetBSD both as host
-(build U-Boot) and target system (boots NetBSD/mpc8xx).
-
-Building requires a cross environment; it is known to work on
-NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
-need gmake since the Makefiles are not compatible with BSD make).
-Note that the cross-powerpc package does not install include files;
-attempting to build U-Boot will fail because <machine/ansi.h> is
-missing. This file has to be installed and patched manually:
-
- # cd /usr/pkg/cross/powerpc-netbsd/include
- # mkdir powerpc
- # ln -s powerpc machine
- # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
- # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
-
-Native builds *don't* work due to incompatibilities between native
-and U-Boot include files.
-
-Booting assumes that (the first part of) the image booted is a
-stage-2 loader which in turn loads and then invokes the kernel
-proper. Loader sources will eventually appear in the NetBSD source
-tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
-meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
-
-
Implementation Internals:
=========================
new address in RAM.
-U-Boot Porting Guide:
-----------------------
-
-[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
-list, October 2002]
-
-
-int main(int argc, char *argv[])
-{
- sighandler_t no_more_time;
-
- signal(SIGALRM, no_more_time);
- alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
-
- if (available_money > available_manpower) {
- Pay consultant to port U-Boot;
- return 0;
- }
-
- Download latest U-Boot source;
-
- Subscribe to u-boot mailing list;
-
- if (clueless)
- email("Hi, I am new to U-Boot, how do I get started?");
-
- while (learning) {
- Read the README file in the top level directory;
- Read https://www.denx.de/wiki/bin/view/DULG/Manual;
- Read applicable doc/README.*;
- Read the source, Luke;
- /* find . -name "*.[chS]" | xargs grep -i <keyword> */
- }
-
- if (available_money > toLocalCurrency ($2500))
- Buy a BDI3000;
- else
- Add a lot of aggravation and time;
-
- if (a similar board exists) { /* hopefully... */
- cp -a board/<similar> board/<myboard>
- cp include/configs/<similar>.h include/configs/<myboard>.h
- } else {
- Create your own board support subdirectory;
- Create your own board include/configs/<myboard>.h file;
- }
- Edit new board/<myboard> files
- Edit new include/configs/<myboard>.h
-
- while (!accepted) {
- while (!running) {
- do {
- Add / modify source code;
- } until (compiles);
- Debug;
- if (clueless)
- email("Hi, I am having problems...");
- }
- Send patch file to the U-Boot email list;
- if (reasonable critiques)
- Incorporate improvements from email list code review;
- else
- Defend code as written;
- }
-
- return 0;
-}
-
-void no_more_time (int sig)
-{
- hire_a_guru();
-}
-
-
-Coding Standards:
------------------
-
-All contributions to U-Boot should conform to the Linux kernel
-coding style; see the kernel coding style guide at
-https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
-script "scripts/Lindent" in your Linux kernel source directory.
-
-Source files originating from a different project (for example the
-MTD subsystem) are generally exempt from these guidelines and are not
-reformatted to ease subsequent migration to newer versions of those
-sources.
-
-Please note that U-Boot is implemented in C (and to some small parts in
-Assembler); no C++ is used, so please do not use C++ style comments (//)
-in your code.
-
-Please also stick to the following formatting rules:
-- remove any trailing white space
-- use TAB characters for indentation and vertical alignment, not spaces
-- make sure NOT to use DOS '\r\n' line feeds
-- do not add more than 2 consecutive empty lines to source files
-- do not add trailing empty lines to source files
-
-Submissions which do not conform to the standards may be returned
-with a request to reformat the changes.
-
-
-Submitting Patches:
--------------------
-
-Since the number of patches for U-Boot is growing, we need to
-establish some rules. Submissions which do not conform to these rules
-may be rejected, even when they contain important and valuable stuff.
-
-Please see https://www.denx.de/wiki/U-Boot/Patches for details.
-
-Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
-see https://lists.denx.de/listinfo/u-boot
-
-When you send a patch, please include the following information with
-it:
-
-* For bug fixes: a description of the bug and how your patch fixes
- this bug. Please try to include a way of demonstrating that the
- patch actually fixes something.
-
-* For new features: a description of the feature and your
- implementation.
-
-* For major contributions, add a MAINTAINERS file with your
- information and associated file and directory references.
-
-* When you add support for a new board, don't forget to add a
- maintainer e-mail address to the boards.cfg file, too.
-
-* If your patch adds new configuration options, don't forget to
- document these in the README file.
-
-* The patch itself. If you are using git (which is *strongly*
- recommended) you can easily generate the patch using the
- "git format-patch". If you then use "git send-email" to send it to
- the U-Boot mailing list, you will avoid most of the common problems
- with some other mail clients.
-
- If you cannot use git, use "diff -purN OLD NEW". If your version of
- diff does not support these options, then get the latest version of
- GNU diff.
-
- The current directory when running this command shall be the parent
- directory of the U-Boot source tree (i. e. please make sure that
- your patch includes sufficient directory information for the
- affected files).
-
- We prefer patches as plain text. MIME attachments are discouraged,
- and compressed attachments must not be used.
-
-* If one logical set of modifications affects or creates several
- files, all these changes shall be submitted in a SINGLE patch file.
-
-* Changesets that contain different, unrelated modifications shall be
- submitted as SEPARATE patches, one patch per changeset.
-
-
-Notes:
-
-* Before sending the patch, run the buildman script on your patched
- source tree and make sure that no errors or warnings are reported
- for any of the boards.
-
-* Keep your modifications to the necessary minimum: A patch
- containing several unrelated changes or arbitrary reformats will be
- returned with a request to re-formatting / split it.
-
-* If you modify existing code, make sure that your new code does not
- add to the memory footprint of the code ;-) Small is beautiful!
- When adding new features, these should compile conditionally only
- (using #ifdef), and the resulting code with the new feature
- disabled must not need more memory than the old code without your
- modification.
+Contributing
+============
-* Remember that there is a size limit of 100 kB per message on the
- u-boot mailing list. Bigger patches will be moderated. If they are
- reasonable and not too big, they will be acknowledged. But patches
- bigger than the size limit should be avoided.
+The U-Boot projects depends on contributions from the user community.
+If you want to participate, please, have a look at the 'General'
+section of https://u-boot.readthedocs.io/en/latest/develop/index.html
+where we describe coding standards and the patch submission process.
projects / platform / kernel / u-boot.git / blobdiff