similar to: "isolinux.bin missing or corrupt" when booting USB flash drive in old PC

Hi, > The ISO will boot successfully (when chainloaded from grub) on 2 and > 3, but not on 5 and 6. Did you try with a boot loader other than GRUB ? Afaik, the MBRs of newly bought USB sticks often contain code which hops on the MBR code of the partition that is marked by the boot flag. At least one could exclude that your problem is in a GRUB peculiarity. Have a nice day :) Thomas

Thomas Schmitt wrote: > My main point of interest is which block is really loaded as first one > of isolinux.bin. [Program snipped.] > (It could be shorter if i did not insist in big endian words.) Why insisting? Anyway appended is a dumper version. I could put up a binery version if needed. Let me know if so. -- MartinS /*

Thomas Schmitt wrote: > I ponder whether it would be possible to create a diagnostic MBR > which does not necessarily have to boot but rather tells what the > isohybrid MBR would perceive: Presence of partition table, > EBIOS or CBIOS, block address used with INT 13, content of the block > read by the first INT 13, ... ... > The diagnostic MBR should only use 432 bytes because at

Hi, do we have bystanders who can read x86 assembler code or know easy-to-grasp reference docs? (I left machine code programming when i gave up using my VIC-20.) The MBR template isohdppx.bin stems from http://git.zytor.com/syslinux/syslinux.git/tree/mbr/isohdpfx.S with macro PARTITION_SUPPORT defined. One can see the error message text in there: bad_signature: call error .ascii

Hi, i am looking now at the code which i assume loads the rest of isolinux.bin. The entry point for program execution from the MBR is obviously at http://git.zytor.com/syslinux/syslinux.git/tree/core/isolinux.asm#n186 (Do i get it right that this is the Intel syntax ? (Gronfff)) If POP yields the victim of the most recent not yet popped PUSH, then this does not look correctly coordinated

Thomas Schmitt wrote: > Since we know that the isolinux.bin binary is well ok on other partitions, > i'd say that the MBR code does not load the right blocks from disk when > it wants to get isolinux.bin. Yes, these are my thoughts as well. I think the jump from GRUB to the isohybrid code on the logical partition is working fine, but when the isohybrid code is trying to jump to

Hi, C/H/S addressing and reading of first block seems to be ok in isohdpfd.bin. The main suspect for the failure of the attempt with isohdpfd.bin is the number or content of the blocks read after the first one. But i have no clue why isohdpfc.bin should do better than isohdpfd.bin. They differ just by one instruction (JC = 0x72 versus JMP = 0xEB) which both are performed before the reading and

It is good to see this ----- Forwarded message from syslinux-bot for Martin Str|mberg <ams at ludd.ltu.se> ----- Date: Sat, 25 Mar 2017 05:54:09 -0700 From: syslinux-bot for Martin Str|mberg <ams at ludd.ltu.se> To: Syslinux commits mailing list <syslinux-commits at zytor.com> Cc: ams at ludd.ltu.se Subject: [syslinux:master] mbr/isohdpfx.S: correct pointer for heads/sectors

Thomas Schmitt wrote: > I have some problems understanding the details of the program's flow. > > - The code inside PARTITION_SUPPORT is supposed to be inactive with > MBR isohdpfx.bin. It belongs to isohybrid --partok which is equivalent > to MBRs isohdppx*.bin. Debian uses isohdpfx.bin. Yes. isohdpfx.bin is generated from isohdpfx.S in which PARTITION_SUPPORT is not

On 03/18/2017 03:02 PM, Thomas Schmitt via Syslinux wrote: > Hi, > > David Christensen wrote: >> I use this USB flash drive for bootable installer images; I do not >> attempt to mount it. I don't know that I could, even if I wanted to: > > mkdir /mnt/iso > mount /dev/sdc /mnt/iso > > or, because partition 1 starts at block 0, you may mount it too >

Hi, given the fact that the conversion has the factor HC*SH = "secpercyl", which is invariant under swapping, there remains as suspect in read_sector_cbios only this division: divb (sectors) There is a suspicious discrepancy in the code: heads = (stack-16) sectors = (stack-18) ... /* here we computer CHS values or just do some dummy computation for EBIOS */ andw $0x3f,

--- mbr/Makefile | 6 +- mbr/mbr-diag.S | 372 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 377 insertions(+), 1 deletions(-) create mode 100644 mbr/mbr-diag.S diff --git a/mbr/Makefile b/mbr/Makefile index 0bdf7e3..b9d743d 100644 --- a/mbr/Makefile +++ b/mbr/Makefile @@ -17,7 +17,7 @@ topdir = .. include $(topdir)/MCONFIG.embedded -all: mbr.bin gptmbr.bin

> Hi, > > i wrote: > > > I think it still has good reason to exist. > > Ady wrote: > > Would you please clarify what do you mean with "it"? > > "It" was the code part about > > xor %cx, %cx /* Clear EBIOS flag. */ > > which Martin mentioned as "can be ignored" in the the text which i > quoted

David Christensen wrote: > What syntax is used in isohdpfx.S -- it doesn't match my Intel gas syntax. "info gas machine i386 i386-syn i386-var" if you have the gas manual installed. -- MartinS

From: MartinS <ams at ludd.ltu.se> isohdp[fp]v.S which says E or C if EBIOS or CBIOS is used. isohdppv.S also says G or M if a GPT or MBR partition is detected. Signed-off-by: MartinS <ams at ludd.ltu.se> --- Comments? diff --git a/mbr/Makefile b/mbr/Makefile index be2bded..7095396 100644 --- a/mbr/Makefile +++ b/mbr/Makefile @@ -21,7 +21,8 @@ include $(MAKEDIR)/embedded.mk all:

On Fri, Mar 24, 2017 at 05:38:31PM +0100, Thomas Schmitt via Syslinux wrote: > isohdpfc pushes the CX value to the stack which it gets from INT 13 AH 41. > Quite surely bit 0 of that CX is not set. But bit 2 "Enhanced Disk Drive" > could be set. > https://en.wikipedia.org/wiki/INT_13H > > I understand on David's BIOS after > > andw $1,%cx

On 03/18/2017 01:18 AM, Ady Ady via Syslinux wrote: > Some of the things you should / could (re)test / (re)try: > > _ Verify the md5sum of the ISO image. SHA256 verified for downloaded image and for contents of USB flash drive (see below). > _ Is this particular USB device _still_ capable of booting newer > computers? Yes. > What happens if you would try _again_ to boot a

Hi, Geert Stappers wrote: > Contact David off-list, he did unsubscribe. Can you tell when he unsubscribed (i.e. which of the messages he got as last one) ? > Martin posted elsewhere in this thread "Thomas, you found the bug" > and provided a patch. Open question is whether the fix helps with David's BIOS. The newest answer from Martin indicates that a failure to read

Hi together, this is the second version of my cross-compilation patch serie. I'm sending it in the hope to get an honest review, and possibly see the patches integrated upstream. Those patches allow to build syslinux using a toolchain different from the host one by explicitely using the host toolchain for the utilities that are required at build-time / on the build machine. I am using the

Hello all, Past few days I was working on porting the isohybrid perl script to c. (-> https://fedorahosted.org/fedora-engineering-services/ticket/15) The first patch towards the same is attached with this mail. And the same could also be accessed from: http://pjp.dgplug.org/tools/syslinux-3.86-isohybrid.patch I would really appreciate it if somebody could have a look at it and let me know