On Tue, Apr 23, 2013 at 08:23:44PM +0300, Michael S. Tsirkin wrote:
> On Mon, Apr 22, 2013 at 08:38:58PM -0400, Kevin O'Connor wrote:
> > On Mon, Apr 22, 2013 at 10:03:01AM +0300, Michael S. Tsirkin wrote:
> > > On Sun, Apr 21, 2013 at 08:39:41PM -0400, Kevin O'Connor wrote:
> > > > On Sun, Apr 21, 2013 at 11:41:48PM +0300, Michael S. Tsirkin wrote:
> > > > > Okay I'm pretty close to posting some patches
> > > > > that advance this project further, but wanted to
> > > > > check something beforehand: there are several tables
> > > > > that point to other tables (for example: FADT points
> > > > > to DSDT). What I did is provide a list of fixups
> > > > > such that bios can patch in pointers without
> > > > > any need to understand what's what.
> > > > > Thoughts?
> > > >
> > > > For the RSDP, RSDT, and FADT I think SeaBIOS should just update those
> > > > tables to set the pointers within them and then recalculate the
> > > > checksum. I don't think anything complex is needed - it's easy for
> > > > SeaBIOS to recognize those special tables and modify them.
> > >
> > > True, that's simple enough. My worry is we can add more such tables.
> > > For example, we can decide to switch to XSDT in the future.
> >
> > I know of the following quirks that would have to be handled:
> >
> > 1 - the RSDP must be in the f-segment (where as all other tables can
> > go into "high" memory).
> >
> > 2 - the RSDP has a checksum in a different location from the other
> > tables and (with an XSDT) it can have two checksums.
> >
> > 3 - the RSDP has a pointer to the RSDT (and to the XSDT if present).
> >
> > 4 - the RSDT (and XSDT if present) has pointers to all the other
> > tables (except RSDP, RSDT, DSDT, and FACS). The FADT pointer must be
> > first in the list.
> >
> > 5 - the FADT table has pointers to DSDT and FACS.
> >
> > 6 - the FACS table must be 64 byte aligned.
> >
> > So, will a generic scheme really be able to handle all of the above
> > quirks, or will we just be mixing some hardcoded quirks with some
> > generic quirks? And, will the code to handle the above quirks in a
> > generic fashion be of a higher complexity than simply hard-coding it?
> >
> > -Kevin
>
> -->
>
> So here's an implementation for align and FSEG.
> Not a big deal as you see.
>
> I really have doubts about it however: BIOS still must be able to parse
> get the resume vector in FACS in order to support wakeup, right? So this
> means that we need to be able to parse RSDP and FACT. These happen to
> be the only things that need anything not addressed by ADD and SUB so
> ... maybe a couple of hardcoded quirks just to allocate these correctly
> is cleaner.
Heh, it's actually pretty easy: let's just ask qemu
to give us the address of the resume vector
in a file with a pre-defined name.
Linker can patch table offset there in the
regular way.
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
>
> ---
>
> diff --git a/src/linker.c b/src/linker.c
> index a1f473d..22a0dff 100644
> --- a/src/linker.c
> +++ b/src/linker.c
> @@ -34,7 +34,9 @@ void linker_link(const char *name)
> if (entry->shift > 63)
> continue;
> if (entry->type != LINKER_ENTRY_TYPE_ADD &&
> - entry->type != LINKER_ENTRY_TYPE_SUB)
> + entry->type != LINKER_ENTRY_TYPE_SUB &&
> + entry->type != LINKER_ENTRY_TYPE_ALIGN &&
> + entry->type != LINKER_ENTRY_TYPE_FSEG)
> continue;
> if (entry->format != LINKER_ENTRY_FORMAT_LE)
> continue;
> @@ -44,17 +46,55 @@ void linker_link(const char *name)
> continue;
> }
> lsrc = strlen(entry->src_dst);
> - if (!lsrc || lsrc + 1 + sizeof *entry >= entry->size) {
> + if (!lsrc) {
> warn_internalerror();
> continue;
> }
> src = romfile_find(entry->src_dst);
> + if (!src) {
> + warn_internalerror();
> + continue;
> + }
> + if (!src->data) {
> + warn_internalerror();
> + continue;
> + }
> + if (entry->type == LINKER_ENTRY_TYPE_ALIGN ||
> + entry->type == LINKER_ENTRY_TYPE_FSEG) {
> + void *data;
> + u32 align;
> + struct zone_s *zone;
> +
> + if (entry->shift > 31) {
> + warn_internalerror();
> + continue;
> + }
> + align = 0x1 << entry->shift;
> + if (align < MALLOC_MIN_ALIGN)
> + align = MALLOC_MIN_ALIGN;
> + zone = entry->type == LINKER_ENTRY_TYPE_FSEG ?
> + &ZoneFSeg : &ZoneHigh;
> + data = pmm_malloc(zone, PMM_DEFAULT_HANDLE, src->size, align);
> + if (!data) {
> + warn_internalerror();
> + continue;
> + }
> + memcpy(data, src->data, src->size);
> + free(src->data);
> + src->data = data;
> + continue;
> + }
> +
> + if (lsrc + 1 + sizeof *entry >= entry->size) {
> + warn_internalerror();
> + continue;
> + }
> dst = romfile_find(entry->src_dst + lsrc + 1);
> - if (!src || !dst) {
> + if (!dst) {
> warn_internalerror();
> continue;
> }
> - if (!src->data || !dst->data) {
> + if (!dst->data) {
> warn_internalerror();
> continue;
> }
> diff --git a/src/linker.h b/src/linker.h
> index 2bb376d..b0cc536 100644
> --- a/src/linker.h
> +++ b/src/linker.h
> @@ -17,9 +17,12 @@ struct linker_entry_s {
> char src_dst[];
> } PACKED;
>
> +/* Note: align types must appear before all other types. */
> enum linker_entry_type {
> LINKER_ENTRY_TYPE_ADD = 0x0,
> LINKER_ENTRY_TYPE_SUB = 0x1,
> + LINKER_ENTRY_TYPE_ALIGN = 0x2, /* Align source to shift bits. Must come
> first. */
> + LINKER_ENTRY_TYPE_FSEG = 0x3, /* Align source to shift bits in FSEG
> memory. */
> };
>
> enum linker_entry_format {
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