Date: Mon, 27 Nov 2023 22:46:23 GMT From: Warner Losh <imp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: c596126a5d3d - main - pmbr: Only load the first 545k rather than error out Message-ID: <202311272246.3ARMkNS1037267@gitrepo.freebsd.org>
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The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=c596126a5d3d2ee015ee6807b4041efa5b9d9b07 commit c596126a5d3d2ee015ee6807b4041efa5b9d9b07 Author: Warner Losh <imp@FreeBSD.org> AuthorDate: 2023-11-27 22:40:40 +0000 Commit: Warner Losh <imp@FreeBSD.org> CommitDate: 2023-11-27 22:45:56 +0000 pmbr: Only load the first 545k rather than error out It would be nice to have larger boot partitions for ESPs to live in one day. It's trivial to carve out 5M 10M or 200M when provisioning, but logistical issues may make it hard to do it after the fact. So only warn when the partition is > 545k. If we ever grow the boot loader larger than that, then it will be responsible for loading the rest anyway. Sponsored by: Netflix Reviewed by: tsoome Differential Revision: https://reviews.freebsd.org/D42774 --- stand/i386/pmbr/pmbr.S | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/stand/i386/pmbr/pmbr.S b/stand/i386/pmbr/pmbr.S index c61acbe261bd..60b26df15720 100644 --- a/stand/i386/pmbr/pmbr.S +++ b/stand/i386/pmbr/pmbr.S @@ -155,8 +155,10 @@ next_boot: addl $1,(%si) # Next LBA mov %es,%ax # Adjust segment for next addw $SECSIZE/16,%ax # sector cmp $0x9000,%ax # Don't load past 0x90000, - jae err_big # 545k should be enough for - mov %ax,%es # any boot code. :) + jb sz_ok # 545k should be enough for + call err_big # any boot code, but warn + mov $0x9000-SECSIZE/16,%ax # and truncate +sz_ok: mov %ax,%es jmp load_boot # # Move to the next partition. If we walk off the end of the sector, load @@ -203,17 +205,21 @@ getdrvparams: # # Various error message entry points. # -err_big: movw $msg_big,%si # "Boot loader too - jmp putstr # large" +err_big: movw $msg_big,%si # "Truncated + call putstr # to 545k" + ret err_pt: movw $msg_pt,%si # "Invalid partition - jmp putstr # table" + call putstr # table" +err_pt.1: jmp err_pt.1 # Await reset err_rd: movw $msg_rd,%si # "I/O error loading - jmp putstr # boot loader" + call putstr # boot loader" + jmp err_pt.1 err_noboot: movw $msg_noboot,%si # "Missing boot - jmp putstr # loader" + call putstr # loader" + jmp err_pt.1 # # Output an ASCIZ string to the console via the BIOS. # @@ -223,9 +229,9 @@ putstr.0: movw $0x7,%bx # Page:attribute putstr: lodsb # Get character testb %al,%al # End of string? jnz putstr.0 # No -putstr.1: jmp putstr.1 # Await reset + ret -msg_big: .asciz "Boot loader too large" +msg_big: .asciz "Loaded only 545k" msg_pt: .asciz "Invalid partition table" msg_rd: .asciz "I/O error loading boot loader" msg_noboot: .asciz "Missing boot loader"
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