[SeaBIOS] [PATCH] Don't overallocate mptable

[Gleb Natapov]

On Thu, Dec 24, 2009 at 11:38:45AM -0500, Kevin O'Connor wrote:
> This patch causes the mptable to be built in temporary memory and then
> copied into the f-segment after it is complete.  This makes better use
> of the limited space in the f-segment, and it makes it less likely an
> overflow will occur (eg, due to many PCI irq entries).
> 
> -Kevin
> 
> 
> diff --git a/src/mptable.c b/src/mptable.c
> index 2409fcf..20c3d63 100644
> --- a/src/mptable.c
> +++ b/src/mptable.c
> @@ -20,30 +20,12 @@ mptable_init(void)
>  
>      dprintf(3, "init MPTable\n");
>  
> -    // Allocate memory
> -    int length = (sizeof(struct mptable_config_s)
> -                  + sizeof(struct mpt_cpu) * MaxCountCPUs
> -                  + sizeof(struct mpt_bus) * 2
> -                  + sizeof(struct mpt_ioapic)
> -                  + sizeof(struct mpt_intsrc) * 34);
> -    struct mptable_config_s *config = malloc_fseg(length);
> -    struct mptable_floating_s *floating = malloc_fseg(sizeof(*floating));
> -    if (!config || !floating) {
> -        dprintf(1, "No room for MPTABLE!\n");
> -        free(config);
> -        free(floating);
> +    // Config structure in temp area.
> +    struct mptable_config_s *config = malloc_tmphigh(32*1024);
> +    if (!config) {
> +        dprintf(1, "No space for temp mptable\n");
>          return;
>      }
> -
> -    /* floating pointer structure */
> -    memset(floating, 0, sizeof(*floating));
> -    floating->signature = MPTABLE_SIGNATURE;
> -    floating->physaddr = (u32)config;
> -    floating->length = 1;
> -    floating->spec_rev = 4;
> -    floating->checksum -= checksum(floating, sizeof(*floating));
> -
> -    // Config structure.
>      memset(config, 0, sizeof(*config));
>      config->signature = MPCONFIG_SIGNATURE;
>      config->spec = 4;
> @@ -115,6 +97,8 @@ mptable_init(void)
>      unsigned short mask = 0, pinmask;
>  
>      foreachpci(bdf, max) {
> +        if (pci_bdf_to_bus(bdf) > 0)
> +            break;
mptable routing info should be created for each pci bus.
See example here:
http://people.freebsd.org/~fsmp/SMP/mptable/t30

Hmm. It looks like we need to create io_bus entries dynamically 
for each newly discovered PCI bus.

--
			Gleb.