similar to: [PATCH 0/3] mbr: Ctrl-key press forces load from first hard disk

Version 2 of these patches includes optimisations suggested by H Peter Alvin to save bytes: * Use memory-mapped I/O register to read keyboard shift flags * Don't reload DX from memory; move immediate byte to register Tested using mbr.bin. TJ (3): mbr: Ctrl-key press forces load from first hard disk gptmbr: Ctrl-key press forces load from first hard disk isohdpfx: Ctrl-key press

--- mbr/Makefile | 6 +- mbr/mbr-diag.S | 377 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 382 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

--- mbr/Makefile | 6 +- mbr/mbr-diag.S | 371 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 376 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

--- 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

--- mbr/isohdpfx.S | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/mbr/isohdpfx.S b/mbr/isohdpfx.S index 9e9d55c..bddb533 100644 --- a/mbr/isohdpfx.S +++ b/mbr/isohdpfx.S @@ -67,6 +67,7 @@ _start: movw %ax, %ss movw $stack, %sp movw %sp, %si + movw %sp, %bp /* needed later if drive number is to be forced due to Ctrl key being pressed */ pushw %es /*

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:

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

If EBIOS is detected for this drive it tries to read sector size and use it. If error or no EBIOS 512 is assumed. Buffer to read sector size if always allocated into the stack. CHS informations are not readed as not needed and same space not restoring %dl for drive number. Signed-off-by: Frediano Ziglio <frediano.ziglio at citrix.com> --- mbr/gptmbr.S | 42

hello everybody, apologies if I'm missing something here Just tried to build 6.04-pre1 test version with: make bios installer and found some problems all (seemingly) related to inaccurate paths in various Makefiles. I enclose a complete patch at the end of this email, which details the problems I found and how they got fixed for me. As an example, this is the first error I got:

This patches add support for dynamic sectors to GPT MBR code. First 3 patches are trick and optimizations to gain some space for the forth patch. I have a modified version of SeaBIOS, some code and some script o test it I'll send on a different mail.

Hi, FYI syslinux upstream has a bugfix. Both in the 6.xx branch and the 4.xx branch. ----- Forwarded message from syslinux-bot for Martin Str|mberg <ams at ludd.ltu.se> ----- Date: Sat, 15 Apr 2017 10:27:08 -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:

Thomas Schmitt said: > I am wondering about the meaning or reason of "+20" in this assembler line: > > movl (32+20)(%si), %ecx > > Why that extra offset 20 on the byte offset 32 which is specified by > GPT specs (UEFI 2.4, 5.3.3) ? (Do i get the language wrong ?) Well I've been looking at this. It seems gptmbr.S

Hi, Gene Cumm wrote: > > There's 0 need to build MBRs for EFI Ady wrote: > At least gptmbr.bin might come to mind It's source code looks like a BIOS MBR program which shall search the "active" partition in GPT rather than in the MBR partition table. See comments about "EBIOS" detection and "CHS" addresses in

> It's source code looks like a BIOS MBR program which shall search > the "active" partition in GPT rather than in the MBR partition table. > See comments about "EBIOS" detection and "CHS" addresses in > https://github.com/geneC/syslinux/blob/master/mbr/gptmbr.S > > "Active" partitn would be the one which has bit 2 set in the

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 /*

Changes: * Fix [C]HS indicator over-write (was showing '5' not 'C') * Use 0xDEAD as magic-bytes filler to make it clear when read_sector didn't replace it * Improvements to commentary and description. TJ (1): Add Diagnostic MBR for trouble-shooting mbr/Makefile | 6 +- mbr/mbr-diag.S | 372 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files

Hi all, I use XP on my laptop PC, with 30 GB HD (single partition), and a 3.5" hard drive (not a stick), accessed through a USB encasing, partitioned as five logical drives. I have successfully set up syslinux to boot several Ubuntu versions from the primary USB hard drive partition, and no problems there. The problem is, I would like to have an entry in the menu, like "Boot from

Ferenc Wagner <wferi at niif.hu> writes: > The internal Gnu-EFI build gives me grief: [...] Previous points still standing, but now I tried cleaning out everything by hand. I don't know whether it matters, but building gnu-efi pollutes its source directory (unlike syslinux itself) with the following files at least (found by git status in the gnu-efi submodule):

> There's 0 need to build MBRs for > EFI At least gptmbr.bin might come to mind (after all, GPT is part of the UEFI specs). Isohybrid with UEFI options perhaps too? > and I'm looking at why utils/ depends on mbr/ isohybrid(.pl) and mkdiskimage come to mind here? I'm not saying for certain these are the reasons for such dependencies, but they might (and perhaps

This is an attempt to avoid potential confusion. Here are some example sizes for the two Syslinux versions mentioned in the e-mail subject. Your build results might be different. 4.06: 1 55 Sep 22 22:23 modules/int18.com 1 108 Nov 1 18:07 version.mk 1 138 Nov 1 18:07 version.gen 1 138 Nov 1 18:07 version.h 1 239 Sep 22 22:23 modules/poweroff.com 1 408 Sep 22 22:25