Sorry for making noise, let me update the diff.
> + if (ed->blkio->Media->IoAlign > 1 &&
> + ((UINTN)buf + i_lblks * DEV_BSIZE)
> + % ed->blkio->Media->IoAlign == 0)
first condition was reversed..
On Wed, 10 Mar 2021 20:35:41 +0900 (JST)
YASUOKA Masahiko <yasu...@openbsd.org> wrote:
> efiboot cannot load the kernel properly on some machines if booted
> from CD-ROM. In that case boot fails with a message like follow:
>
> booting cd0a:..... [359648read symbols: Unknown error: code 255
>
> As far as Asou and my test, this happens on hosts on VMware ESXi 6.7,
> 7.0 and asou's physical machine.
>
> The problem happens because efiboot calls ReadBlocks function with an
> unaligned pointer for medias which requires an aligned pointer. When
> efiboot loads a kernel, the pointer becomes unaligned since there is
> an ELF section located at unaligned place in CD-ROM. Previously our
> kernel didn't have such a section but it does after switching lld as
> the default linker.
>
> For test, let me show sample commands which creates a bootable cdrom
> image for EFI:
>
> mkdir -p efiboot/EFI/BOOT
> cp /usr/mdec/BOOTX64.EFI efiboot/EFI/BOOT
> makefs -M 1m -m 1m -t msdos -o fat_type=12,sectors_per_cluster=1 \
> efiboot.img efiboot
> mkdir -p cd-dir/etc
> cp bsd.rd cd-dir/
> echo "set image bsd.rd" > cd-dir/etc/boot.conf
> makefs -t cd9660 -o
> 'rockridge,bootimage=i386;/usr/mdec/cdbr,no-emul-boot,allow-multidot,bootimage=efi;efiboot.img,no-emul-boot'
> \
> boot.iso cd-dir
>
> the diff is to fix the problem.
>
> ok?
Index: sys/arch/amd64/stand/efiboot/efidev.c
===================================================================
RCS file: /disk/cvs/openbsd/src/sys/arch/amd64/stand/efiboot/efidev.c,v
retrieving revision 1.32
diff -u -p -r1.32 efidev.c
--- sys/arch/amd64/stand/efiboot/efidev.c 9 Dec 2020 18:10:18 -0000
1.32
+++ sys/arch/amd64/stand/efiboot/efidev.c 10 Mar 2021 11:41:39 -0000
@@ -84,7 +84,7 @@ efid_init(struct diskinfo *dip, void *ha
static EFI_STATUS
efid_io(int rw, efi_diskinfo_t ed, u_int off, int nsect, void *buf)
{
- u_int blks, lba, i_lblks, i_tblks, i_nblks;
+ u_int i, blks, lba, i_lblks, i_tblks, i_nblks;
EFI_STATUS status = EFI_SUCCESS;
static u_char *iblk = NULL;
static u_int iblksz = 0;
@@ -127,10 +127,29 @@ efid_io(int rw, efi_diskinfo_t ed, u_int
min(nsect, i_lblks) * DEV_BSIZE);
}
if (i_nblks > 0) {
- status = EFI_CALL(ed->blkio->ReadBlocks,
- ed->blkio, ed->mediaid, lba,
- ed->blkio->Media->BlockSize * (i_nblks / blks),
- buf + (i_lblks * DEV_BSIZE));
+ /*
+ * Pass the buffer directly to the EFI function only if
+ * the buffer is properly aligned as the media requires
+ */
+ if (ed->blkio->Media->IoAlign <= 1 ||
+ ((UINTN)buf + i_lblks * DEV_BSIZE)
+ % ed->blkio->Media->IoAlign == 0)
+ status = EFI_CALL(ed->blkio->ReadBlocks,
+ ed->blkio, ed->mediaid, lba,
+ ed->blkio->Media->BlockSize * (i_nblks /
+ blks), buf + i_lblks * DEV_BSIZE);
+ else {
+ for (i = 0; i < i_nblks; i += blks) {
+ status = EFI_CALL(ed->blkio->ReadBlocks,
+ ed->blkio, ed->mediaid,
+ lba + i / blks,
+ ed->blkio->Media->BlockSize, iblk);
+ if (EFI_ERROR(status))
+ break;
+ memcpy(buf + i * DEV_BSIZE, iblk,
+ ed->blkio->Media->BlockSize);
+ }
+ }
if (EFI_ERROR(status))
goto on_eio;
}
@@ -160,10 +179,30 @@ efid_io(int rw, efi_diskinfo_t ed, u_int
ed->blkio->Media->BlockSize, iblk);
}
if (i_nblks > 0) {
- status = EFI_CALL(ed->blkio->WriteBlocks,
- ed->blkio, ed->mediaid, lba,
- ed->blkio->Media->BlockSize * (i_nblks / blks),
- buf + (i_lblks * DEV_BSIZE));
+ /*
+ * Pass the buffer directly to the EFI function only if
+ * the buffer is properly aligned as the media requires
+ */
+ if (ed->blkio->Media->IoAlign <= 1 ||
+ ((UINTN)buf + i_lblks * DEV_BSIZE)
+ % ed->blkio->Media->IoAlign == 0)
+ status = EFI_CALL(ed->blkio->WriteBlocks,
+ ed->blkio, ed->mediaid, lba,
+ ed->blkio->Media->BlockSize * (i_nblks /
+ blks), buf + i_lblks * DEV_BSIZE);
+ else {
+ for (i = 0; i < i_nblks; i += blks) {
+ memcpy(iblk, buf + i * DEV_BSIZE,
+ ed->blkio->Media->BlockSize);
+ status = EFI_CALL(
+ ed->blkio->WriteBlocks,
+ ed->blkio, ed->mediaid,
+ lba + i / blks,
+ ed->blkio->Media->BlockSize, iblk);
+ if (EFI_ERROR(status))
+ break;
+ }
+ }
if (EFI_ERROR(status))
goto on_eio;
}
