Hello,
I'm trying to load Memtest86+ on the Mohon Peak reference board from CBFS and it fails. My primary payload is SeaBIOS. Memtest is added using cbfstool, so the layout of my ROM file is as follows:
$ ./build/cbfstool build/coreboot.rom print coreboot.rom: 8192 kB, bootblocksize 1024, romsize 8388608, offset 0x600000 alignment: 64 bytes, architecture: x86
Name Offset Type Size cmos_layout.bin 0x600000 cmos_layout 1352 fallback/romstage 0x600580 stage 26616 fallback/ramstage 0x606dc0 stage 60446 fallback/payload 0x615a40 payload 55799 config 0x623480 raw 4323 revision 0x6245c0 raw 714 img/Memtest86+ 0x6248c0 payload 225028 (empty) 0x65b800 null 1001368 mrc.cache 0x74ffc0 (unknown) 65536 cpu_microcode_blob.bin 0x760000 microcode 83968 (empty) 0x774840 null 46936 fsp.bin 0x77ffc0 (unknown) 372736 (empty) 0x7db000 null 150424
I've tried versions 4.20 and 5.01. Memtest86+ v4.20 just hangs, here is output of SeaBIOS trying to load it: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 194420@0xffe24920 -> 194420@0x00000000 No compression
And then nothing. Memtest86+ v5.01 goes a bit further, SeaBIOS finds its entry point: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 224972@0xffe24920 -> 224972@0x00000000 No compression Calling addr 0x00010000
But after this the board reboots. I also tried to load Memtest from HDD using Grub and v4.20 seems to work fine, while v5.01 causing reboot just like in case with CBFS. And I also tried to add Memtest as a primary payload without SeaBIOS. Again, v5.01 causes reboot. And v4.20 cannot find linuxbios tables.
Viktor
Kuzmichev Viktor wrote:
v5.01 causes reboot. And v4.20 cannot find linuxbios tables.
Probably the code doesn't really know how to work on coreboot. The project was renamed from LinuxBIOS to coreboot in 2008, so it seems noone looked very closely at the code since then.
//Peter
* Kuzmichev Viktor kuzmichevviktorv@gmail.com [150120 14:31]:
Hello,
I'm trying to load Memtest86+ on the Mohon Peak reference board from CBFS and it fails. My primary payload is SeaBIOS. Memtest is added using cbfstool, so the layout of my ROM file is as follows:
$ ./build/cbfstool build/coreboot.rom print coreboot.rom: 8192 kB, bootblocksize 1024, romsize 8388608, offset 0x600000 alignment: 64 bytes, architecture: x86
Name Offset Type Size cmos_layout.bin 0x600000 cmos_layout 1352 fallback/romstage 0x600580 stage 26616 fallback/ramstage 0x606dc0 stage 60446 fallback/payload 0x615a40 payload 55799 config 0x623480 raw 4323 revision 0x6245c0 raw 714 img/Memtest86+ 0x6248c0 payload 225028 (empty) 0x65b800 null 1001368 mrc.cache 0x74ffc0 (unknown) 65536 cpu_microcode_blob.bin 0x760000 microcode 83968 (empty) 0x774840 null 46936 fsp.bin 0x77ffc0 (unknown) 372736 (empty) 0x7db000 null 150424
I've tried versions 4.20 and 5.01. Memtest86+ v4.20 just hangs, here is output of SeaBIOS trying to load it: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 194420@0xffe24920 -> 194420@0x00000000 No compression
And then nothing. Memtest86+ v5.01 goes a bit further, SeaBIOS finds its entry point: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 224972@0xffe24920 -> 224972@0x00000000 No compression Calling addr 0x00010000
It looks like in both cases memtest86+ is loaded at address 0x00000000 which will overwrite a bunch of memory, including the coreboot tables. Looks like the memtest86+ elf binary needs to specify a load address.
Stefan
Hello Stefan,
Thank you for the tip, I'm currently looking into that. But I'm still not sure how to specify the load address. My guess is that I should edit the linking script properly to do it. By default it looks as follows (memtest.lds):
OUTPUT_FORMAT("elf32-i386"); OUTPUT_ARCH(i386);
ENTRY(_start); SECTIONS { . = 0x10000; _start = . ; .data : { *(.data) } }
And here is the output of 'readelf -a memtest' command:
ELF Header: Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: Intel 80386 Version: 0x1 Entry point address: 0x10000 Start of program headers: 52 (bytes into file) Start of section headers: 239496 (bytes into file) Flags: 0x0 Size of this header: 52 (bytes) Size of program headers: 32 (bytes) Number of program headers: 1 Size of section headers: 40 (bytes) Number of section headers: 3 Section header string table index: 2
Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .data PROGBITS 00010000 010000 02a774 00 WA 0 0 1 [ 2] .shstrtab STRTAB 00000000 03a774 000011 00 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific)
There are no section groups in this file.
Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0x00000000 0x00000000 0x3a774 0x3a774 RW 0x200000
Section to Segment mapping: Segment Sections... 00 .data
There is no dynamic section in this file.
There are no relocations in this file.
The decoding of unwind sections for machine type Intel 80386 is not currently supported.
No version information found in this file.
So, the entry point is at the offset of 0x10000. But I think I should somehow change the 'VirtAddr'. I've tried to edit the script in different ways, for example, I've tried to add MEMORY command and then allocate certain sections to the regions as explained here: https://sourceware.org/binutils/docs/ld/REGION_005fALIAS.html#REGION_005fALI...
but haven't come to any success yet.
Are there any advices you could give me? Am I even looking in the right direction?
Thanks in advance, Viktor
On 20.01.2015 22:33, Stefan Reinauer wrote:
- Kuzmichev Viktor kuzmichevviktorv@gmail.com [150120 14:31]:
Hello,
I'm trying to load Memtest86+ on the Mohon Peak reference board from CBFS and it fails. My primary payload is SeaBIOS. Memtest is added using cbfstool, so the layout of my ROM file is as follows:
$ ./build/cbfstool build/coreboot.rom print coreboot.rom: 8192 kB, bootblocksize 1024, romsize 8388608, offset 0x600000 alignment: 64 bytes, architecture: x86
Name Offset Type Size cmos_layout.bin 0x600000 cmos_layout 1352 fallback/romstage 0x600580 stage 26616 fallback/ramstage 0x606dc0 stage 60446 fallback/payload 0x615a40 payload 55799 config 0x623480 raw 4323 revision 0x6245c0 raw 714 img/Memtest86+ 0x6248c0 payload 225028 (empty) 0x65b800 null 1001368 mrc.cache 0x74ffc0 (unknown) 65536 cpu_microcode_blob.bin 0x760000 microcode 83968 (empty) 0x774840 null 46936 fsp.bin 0x77ffc0 (unknown) 372736 (empty) 0x7db000 null 150424
I've tried versions 4.20 and 5.01. Memtest86+ v4.20 just hangs, here is output of SeaBIOS trying to load it: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 194420@0xffe24920 -> 194420@0x00000000 No compression
And then nothing. Memtest86+ v5.01 goes a bit further, SeaBIOS finds its entry point: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 224972@0xffe24920 -> 224972@0x00000000 No compression Calling addr 0x00010000
It looks like in both cases memtest86+ is loaded at address 0x00000000 which will overwrite a bunch of memory, including the coreboot tables. Looks like the memtest86+ elf binary needs to specify a load address.
Stefan
On Fri, Jan 23, 2015 at 1:45 AM, Kuzmichev Viktor kuzmichevviktorv@gmail.com wrote:
Hello Stefan,
Thank you for the tip, I'm currently looking into that. But I'm still not sure how to specify the load address. My guess is that I should edit the linking script properly to do it. By default it looks as follows (memtest.lds):
OUTPUT_FORMAT("elf32-i386"); OUTPUT_ARCH(i386);
ENTRY(_start); SECTIONS { . = 0x10000; _start = . ; .data : { *(.data) } }
And here is the output of 'readelf -a memtest' command:
ELF Header: Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: Intel 80386 Version: 0x1 Entry point address: 0x10000 Start of program headers: 52 (bytes into file) Start of section headers: 239496 (bytes into file) Flags: 0x0 Size of this header: 52 (bytes) Size of program headers: 32 (bytes) Number of program headers: 1 Size of section headers: 40 (bytes) Number of section headers: 3 Section header string table index: 2
Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .data PROGBITS 00010000 010000 02a774 00 WA 0 0 1 [ 2] .shstrtab STRTAB 00000000 03a774 000011 00 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific)
There are no section groups in this file.
Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0x00000000 0x00000000 0x3a774 0x3a774 RW 0x200000
Section to Segment mapping: Segment Sections... 00 .data
There is no dynamic section in this file.
There are no relocations in this file.
The decoding of unwind sections for machine type Intel 80386 is not currently supported.
No version information found in this file.
So, the entry point is at the offset of 0x10000. But I think I should somehow change the 'VirtAddr'. I've tried to edit the script in different ways, for example, I've tried to add MEMORY command and then allocate certain sections to the regions as explained here: https://sourceware.org/binutils/docs/ld/REGION_005fALIAS.html#REGION_005fALI... but haven't come to any success yet.
Are there any advices you could give me? Am I even looking in the right direction?
Ya. You are on the right path. I just confirmed your findings locally. What you'd like to see is VirtAddr/PhysAddr = 0x10000 as well as offset to be 0x10000 because that would match with .data section. Also notice that MemSiz is 0x10000 greater than the Size of the .data section. So when this payload is loading all memory from 0x00000 to 0x10000 is filled with zeros before the start of the program at 0x10000.
I poked around in trying to relink in different ways but it kept loading at 0. You could hexedit the memtest elf file. Apparently there is an 'ht editor' program. However, I couldn't for the life of me figure it out, but I was able to make it coredump trying to figure out how to navigate it. :/
But I just found this page: http://dwarfdump.blogspot.com/2009/08/executable-file-editor-elf-editor.html
$ hte memtest
<hit space>
Goto 'elf/program headers'. Hit <enter>
Expand 'entry 0' with <enter> Goto 'offset' Hit <F4>. Make 'offset', 'virtual address', 'physical address' all to 00010000 Make 'in file size' and 'in memory size' 00027008.
Hit <F2> to save. Hit <F10> to quit.
Those values were based on the memtest I compiled: $ readelf -e memtest ELF Header: Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: Intel 80386 Version: 0x1 Entry point address: 0x10000 Start of program headers: 52 (bytes into file) Start of section headers: 225308 (bytes into file) Flags: 0x0 Size of this header: 52 (bytes) Size of program headers: 32 (bytes) Number of program headers: 1 Size of section headers: 40 (bytes) Number of section headers: 3 Section header string table index: 2
Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .data PROGBITS 00010000 010000 027008 00 WA 0 0 1 [ 2] .shstrtab STRTAB 00000000 037008 000011 00 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific)
Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0x00000000 0x00000000 0x37008 0x37008 RW 0x200000
Section to Segment mapping: Segment Sections... 00 .data
After the instructions above I get the following:
$ readelf -e memtest ELF Header: Magic: 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 Class: ELF32 Data: 2's complement, little endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: EXEC (Executable file) Machine: Intel 80386 Version: 0x1 Entry point address: 0x10000 Start of program headers: 52 (bytes into file) Start of section headers: 225308 (bytes into file) Flags: 0x0 Size of this header: 52 (bytes) Size of program headers: 32 (bytes) Number of program headers: 1 Size of section headers: 40 (bytes) Number of section headers: 3 Section header string table index: 2
Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .data PROGBITS 00010000 010000 027008 00 WA 0 0 1 [ 2] .shstrtab STRTAB 00000000 037008 000011 00 0 0 1 Key to Flags: W (write), A (alloc), X (execute), M (merge), S (strings) I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown) O (extra OS processing required) o (OS specific), p (processor specific)
Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x010000 0x00010000 0x00010000 0x27008 0x27008 RW 0x200000
Section to Segment mapping: Segment Sections... 00 .data
Notice now that we're only loading the .data section at 0x10000. I hope that helps.
Thanks in advance, Viktor
On 20.01.2015 22:33, Stefan Reinauer wrote:
- Kuzmichev Viktor kuzmichevviktorv@gmail.com [150120 14:31]:
Hello,
I'm trying to load Memtest86+ on the Mohon Peak reference board from CBFS and it fails. My primary payload is SeaBIOS. Memtest is added using cbfstool, so the layout of my ROM file is as follows:
$ ./build/cbfstool build/coreboot.rom print coreboot.rom: 8192 kB, bootblocksize 1024, romsize 8388608, offset 0x600000 alignment: 64 bytes, architecture: x86
Name Offset Type Size cmos_layout.bin 0x600000 cmos_layout 1352 fallback/romstage 0x600580 stage 26616 fallback/ramstage 0x606dc0 stage 60446 fallback/payload 0x615a40 payload 55799 config 0x623480 raw 4323 revision 0x6245c0 raw 714 img/Memtest86+ 0x6248c0 payload 225028 (empty) 0x65b800 null 1001368 mrc.cache 0x74ffc0 (unknown) 65536 cpu_microcode_blob.bin 0x760000 microcode 83968 (empty) 0x774840 null 46936 fsp.bin 0x77ffc0 (unknown) 372736 (empty) 0x7db000 null 150424
I've tried versions 4.20 and 5.01. Memtest86+ v4.20 just hangs, here is output of SeaBIOS trying to load it: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 194420@0xffe24920 -> 194420@0x00000000 No compression
And then nothing. Memtest86+ v5.01 goes a bit further, SeaBIOS finds its entry point: Trying CBFS Booting from CBFS... Run img/Memtest86+ Segment 41544144 224972@0xffe24920 -> 224972@0x00000000 No compression Calling addr 0x00010000
It looks like in both cases memtest86+ is loaded at address 0x00000000 which will overwrite a bunch of memory, including the coreboot tables. Looks like the memtest86+ elf binary needs to specify a load address.
Stefan
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Stefan Reinauer