[SeaBIOS] [PATCH 3/3] add ahci support

[Kevin O'Connor]

On Thu, Nov 25, 2010 at 04:42:31PM +0100, Gerd Hoffmann wrote:
> This patch adds AHCI support to seabios.  Tested with virtual hardware
> only (upcoming ahci support in qemu).  Coded by looking at the
> recommandations in the intel ahci specs, so I don't expect much trouble
> on real hardware.  Tested booting fedora install from hard disk and a
> opensuse live iso from cdrom.

Hi Gerd,

Looks good to me.  I have a few comments below.

[...]
> --- /dev/null
> +++ b/src/ahci.c
[...]
> +// prepare sata command fis
> +static void memset_fl(void *ptr, u8 val, size_t size)
> +{
> +#if MODESEGMENT == 1
> +    memset_far(FLATPTR_TO_SEG(ptr), (void*)(FLATPTR_TO_OFFSET(ptr)),
> +               val, size);
> +#else
> +    memset(ptr, val, size);
> +#endif
> +}

This should move to util.c.  Also, I'd prefer to avoid "#if" where
possible.

[...]
> +// command demuxer
> +int process_ahci_op(struct disk_op_s *op)
> +{
> +        switch (op->command) {
> +        case CMD_READ:
> +            return ahci_disk_readwrite(op, 0);
> +        case CMD_RESET:
[...]

Is CMD_WRITE purposefuly not supported?  If so, I think it should
return DISK_RET_EWRITEPROTECT.

[...]
> +    port->list = memalign_low(1024, 1024);
> +    port->fis = memalign_low(256, 256);
> +    port->cmd = memalign_low(256, 256);
> +    if (port->list == NULL || port->fis == NULL || port->cmd == NULL) {
> +        warn_noalloc();
> +        return NULL;
> +    }
[...]
> +    port->drive.desc = malloc_tmp(MAXDESCSIZE);

Should check for no memory on this malloc too.

[...]
> --- a/src/config.h
> +++ b/src/config.h
> @@ -52,6 +52,8 @@
>  #define CONFIG_PS2PORT 1
>  // Support for IDE disk code
>  #define CONFIG_ATA 1
> +// Support for AHCI disk code
> +#define CONFIG_AHCI 1

I think this should default to off until there has been some
additional feedback - two things are unknown - how this handles real
hardware and how popular OSes handle real->protected switching.

Otherwise, looks good to me.  I'm okay with committing.

-Kevin