similar to: [PATCH 4/4] Support sectors >512

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 /*

On Sat, Mar 25, 2017 at 06:51:50PM +0100, Geert Stappers via Syslinux wrote: > 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> > Subject: [syslinux:master] mbr/isohdpfx.S: correct pointer for

On Fri, Mar 24, 2017 at 2:55 PM, Martin Str|mberg via Syslinux <syslinux at zytor.com> wrote: > 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. >>

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,

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

--- 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

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 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

--- 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 | 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

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, 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

On Wed, Mar 22, 2017 at 12:06:12PM +0100, Thomas Schmitt via Syslinux wrote: > 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, %cx /* Sector count */ > popw %bx /* EBIOS flag */ > pushw %cx /* -16: Save

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:

This set of patches add some support for sector size >512. Currently it fixes extlinux, MBR for GPT and ext partitions. Other code is unaffected. This set of patches has been tested on a read Dell machine running a beta firmware.

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

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

git://git.zytor.com/users/genec/syslinux.git Branch handoff-mbr-for-hpa This is a piece of code that can be used in place of a MBR or VBR/PBR (master boot record; volume/partition) in order to examine the data handed to the respective boot code. AX, SS, and SP are destroyed before examining anything. I set an internal restriction that limits it to 420 bytes such that it could be used with a

The handover protocol uses ED as partition type but the comment above it still mentions EE Signed-off-by: Ruben Kerkhof <ruben at rubenkerkhof.com> --- mbr/gptmbr.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S index 7f450d3..8ab6b50 100644 --- a/mbr/gptmbr.S +++ b/mbr/gptmbr.S @@ -194,7 +194,7 @@ found_part: pushw %di /* 80 00 00 00

Op 2013-12-15 om 17:39 schreef Ferenc Wagner: > Ruben Kerkhof <ruben at rubenkerkhof.com> writes: > > > /* 80 00 00 00 ee 00 00 00 > > - - bootable partition, type EFI (EE), no CHS information */ > > + - bootable partition, type EFI (ED), no CHS information */ > > Please fix the previous comment line as well. As I understand that, so in _my words_: