Re: [Xen-devel] [PATCH 06/16] arm: parse modules from DT during early boot.

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2012-09-06 at 12:47 +0100, Tim Deegan wrote:
> At 13:30 +0000 on 03 Sep (1346679046), Ian Campbell wrote:
> > The bootloader should populate /chosen/nr-modules with the number of
> > modules and then for each module 0..nr-modules-1 it should populate
> > /chosen/moduleN-{start,end} with the physical address of the module.
> 
> The code below looks like it's expecting the modules to be numbered from
> 1, not from 0.

Yes, looks like I'd forgotten that by the time I wrote the commit
message. Thanks.

Ian.

> 
> Tim.
> 
> > The hypervisor allows for 2 modules (kernel and initrd). Currently we
> > don't do anything with them.
> > 
> > Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > ---
> >  xen/common/device_tree.c      |   57 
> > +++++++++++++++++++++++++++++++++++++++++
> >  xen/include/xen/device_tree.h |    7 +++++
> >  2 files changed, 64 insertions(+), 0 deletions(-)
> > 
> > diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
> > index 3d1f0f4..226e3f3 100644
> > --- a/xen/common/device_tree.c
> > +++ b/xen/common/device_tree.c
> > @@ -229,6 +229,61 @@ static void __init process_memory_node(const void 
> > *fdt, int node,
> >      }
> >  }
> >  
> > +static void __init process_chosen_node(const void *fdt, int node,
> > +                                       const char *name,
> > +                                       u32 address_cells, u32 size_cells)
> > +{
> > +    const struct fdt_property *prop;
> > +    const u32 *cell;
> > +    paddr_t size;
> > +    int i, nr_modules;
> > +
> > +    prop = fdt_get_property(fdt, node, "nr-modules", NULL);
> > +    if ( !prop )
> > +    {
> > +        early_info.modules.nr_mods = 0;
> > +        return;
> > +    }
> > +
> > +    cell = (const u32 *)prop->data;
> > +    get_val(&cell, 1, (u64*)&nr_modules);
> > +
> > +    if ( nr_modules > NR_MODULES )
> > +    {
> > +        early_panic("too many modules %d > %d\n", nr_modules, NR_MODULES);
> > +    }
> > +
> > +    for ( i = 0; i < nr_modules; i++ )
> > +    {
> > +        struct membank *mod = &early_info.modules.module[i];
> > +        /* longest prop name is "start", single digit numbers of modules */
> > +        char propname[strlen("moduleX-start") + 1];
> > +
> > +        BUILD_BUG_ON(NR_MODULES > 9);
> > +
> > +        snprintf(propname, sizeof(propname), "module%d-start", i+1);
> > +        prop = fdt_get_property(fdt, node, propname, NULL);
> > +        if ( !prop )
> > +            early_panic("no start for module %d\n", i);
> > +
> > +        cell = (const u32 *)prop->data;
> > +        device_tree_get_reg(&cell, address_cells, size_cells,
> > +                            &mod->start, &size);
> > +
> > +        snprintf(propname, sizeof(propname), "module%d-end", i+1);
> > +        prop = fdt_get_property(fdt, node, propname, NULL);
> > +        if ( !prop )
> > +            early_panic("no end for module %d\n", i);
> > +
> > +        cell = (const u32 *)prop->data;
> > +        device_tree_get_reg(&cell, address_cells, size_cells,
> > +                            &mod->size, &size);
> > +        mod->size -= mod->start;
> > +    }
> > +
> > +    early_info.modules.nr_mods = nr_modules;
> > +}
> > +
> >  static int __init early_scan_node(const void *fdt,
> >                                    int node, const char *name, int depth,
> >                                    u32 address_cells, u32 size_cells,
> > @@ -236,6 +291,8 @@ static int __init early_scan_node(const void *fdt,
> >  {
> >      if ( device_tree_node_matches(fdt, node, "memory") )
> >          process_memory_node(fdt, node, name, address_cells, size_cells);
> > +    else if ( device_tree_node_matches(fdt, node, "chosen") )
> > +        process_chosen_node(fdt, node, name, address_cells, size_cells);
> >  
> >      return 0;
> >  }
> > diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
> > index 4d010c0..585fcc9 100644
> > --- a/xen/include/xen/device_tree.h
> > +++ b/xen/include/xen/device_tree.h
> > @@ -15,6 +15,7 @@
> >  #define DEVICE_TREE_MAX_DEPTH 16
> >  
> >  #define NR_MEM_BANKS 8
> > +#define NR_MODULES 2
> >  
> >  struct membank {
> >      paddr_t start;
> > @@ -26,8 +27,14 @@ struct dt_mem_info {
> >      struct membank bank[NR_MEM_BANKS];
> >  };
> >  
> > +struct dt_module_info {
> > +    int nr_mods;
> > +    struct membank module[NR_MODULES];
> > +};
> > +
> >  struct dt_early_info {
> >      struct dt_mem_info mem;
> > +    struct dt_module_info modules;
> >  };
> >  
> >  typedef int (*device_tree_node_func)(const void *fdt,
> > -- 
> > 1.7.9.1
> > 
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-devel



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