83b8f0c485
src/lib/ code in coreboot. I.e. the tool changes but the coreboot code
does not.
Currently, as cbfstool manages the ROM, there are files and empty
space. To allocate files, the code does, first, a walk of the headers
and, if that fails, does a brute-force search of the rest of the
space.
We all agree that the brute-force search has lots of problems from a
performance and correctness standpoint.
I've made a slight change. Instead of an "empty space" area with no
valid headers, I've made a header for the empty space.
So cbfs creation looks like this:
- set up the boot block
- create a file, of type CBFS_COMPONENT_NULL, that contains the empty
space. CBFS_COMPONENT_NULL was already defined in cbfs.h
Here's an example:
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs create 1048576 2048
(cbfstool) E: Unable to open (null): Bad address
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs print
testcbfs: 1024 kB, bootblocksize 2048, romsize 1048576, offset 0x0
Alignment: 16 bytes
Name Offset Type Size
0x0 0xffffffff 1046456
So how do we create a new file?
It's easy: walk the files and find a file of type CBFS_COMPONENT_NULL,
which is as large
or larger than the file you are trying to create. Then you use that file.
- if the file is the same size as the NULL file, then it's easy: take it
- if the file is smaller than the NULL file, you split the NULL file
into two parts.
note that this works in the base case: the base case is that the whole
storage is CBFS_COMPONENT_NULL.
Here's an example of adding a file.
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs add-stage testfixed t
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs print
testcbfs: 1024 kB, bootblocksize 2048, romsize 1048576, offset 0x0
Alignment: 16 bytes
Name Offset Type Size
t 0x0 stage 23176
0x5ab0 0xffffffff 1023240
Note that the NULL split and got smaller. But the entire ROM is still
contained by the two files. To walk this entire rom will require two
FLASH accesses.
Add another file:
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs add-stage testfixed tt
[rminnich@xcpu2 cbfstool]$ ./cbfstool testcbfs print
testcbfs: 1024 kB, bootblocksize 2048, romsize 1048576, offset 0x0
Alignment: 16 bytes
Name Offset Type Size
t 0x0 stage 23176
tt 0x5ab0 stage 23176
0xb560 0xffffffff 1000024
[rminnich@xcpu2 cbfstool]$
So, taking current ROMs as an example, I can reduce FLASH accesses for
cbfs from (potentially) thousands to (typically) less than 10.
Index: fs.c
Changes for readability and cleanliness. Move common blobs of code to functions.
New function: rom_alloc,which allocates files by finding NULL files and using/splitting.
Other changes as needed to support this usage.
Index: util.c
Creating a cbfs archive now requires creation of a NULL file covering the file system space.
Index: cbfs.h
Add a DELETED file type with value 0. Any file can be marked deleted by zero its type; this is a
FLASH-friendly definition for all known FLASH types.
Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>
I think it is a step in the right direction. Could you add the
function prototype to cbfstool.h?
Acked-by: Myles Watson <mylesgw@gmail.com>
(I added the prototype)
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@4261 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
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README
------------------------------------------------------------------------------- coreboot README ------------------------------------------------------------------------------- coreboot is a Free Software project aimed at replacing the proprietary BIOS you can find in most of today's computers. It performs just a little bit of hardware initialization and then executes one of many possible payloads, e.g. a Linux kernel or a bootloader. Payloads -------- After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot. See http://www.coreboot.org/Payloads for a list of supported payloads. Supported Hardware ------------------ coreboot supports a wide range of chipsets, devices, and mainboards. For details please consult: * http://www.coreboot.org/Supported_Motherboards * http://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * gcc / g++ * make * python * perl Optional: * doxygen (for generating/viewing documentation) * iasl (for targets with ACPI support) * gdb (for better debugging facilities on some targets) Building coreboot ----------------- Please consult http://www.coreboot.org/Documentation for details. Testing coreboot Without Modifying Your Hardware ------------------------------------------------- If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU. Please see http://www.coreboot.org/QEMU for details. Website and Mailing List ------------------------ Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website: http://www.coreboot.org You can contact us directly on the coreboot mailing list: http://www.coreboot.org/Mailinglist Copyright and License --------------------- The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details. coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files (mostly those derived from the Linux kernel) are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details. This makes the resulting coreboot images licensed under the GPL, version 2.