[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 04/12] arm: parse modules from DT during early boot.
At 16:23 +0000 on 13 Nov (1352823796), Ian Campbell wrote: > The bootloader should populate /chosen/module@<N>/ for each module it > wishes to pass to the hypervisor. The content of these nodes is > described in docs/misc/arm/device-tree/booting.txt > > The hypervisor allows for 2 modules (@1==kernel and @2==initrd). > Currently we don't do anything with them. > > Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx> > --- > v2: Reserve the zeroeth module for Xen itself (not used yet) > Use a more idiomatic DT layout > Document said layout > --- > docs/misc/arm/device-tree/booting.txt | 27 ++++++++++++ > xen/common/device_tree.c | 75 > +++++++++++++++++++++++++++++++++ > xen/include/xen/device_tree.h | 14 ++++++ > 3 files changed, 116 insertions(+), 0 deletions(-) > create mode 100644 docs/misc/arm/device-tree/booting.txt > > diff --git a/docs/misc/arm/device-tree/booting.txt > b/docs/misc/arm/device-tree/booting.txt > new file mode 100644 > index 0000000..2609450 > --- /dev/null > +++ b/docs/misc/arm/device-tree/booting.txt > @@ -0,0 +1,27 @@ > +Xen is passed the dom0 kernel and initrd via a reference in the /chosen > +node of the device tree. > + > +Each node has the form /chosen/module@<N> and contains the following > +properties: > + > +- compatible > + > + Must be "xen,multiboot-module" > + > +- start > + > + Physical address of the start of this module > + > +- end > + > + Physical address of the end of this module > + > +- bootargs (optional) > + > + Command line associated with this module > + > +The following modules are understood > + > +- 1 -- the domain 0 kernel > +- 2 -- the domain 0 ramdisk > + > diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c > index 3d1f0f4..efd1663 100644 > --- a/xen/common/device_tree.c > +++ b/xen/common/device_tree.c > @@ -229,6 +229,79 @@ 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 nr, depth, nr_modules = 0; > + struct dt_mb_module *mod; > + int len; > + > + for ( depth = 0; > + depth >= 0; > + node = fdt_next_node(fdt, node, &depth) ) > + { > + name = fdt_get_name(fdt, node, NULL); > + if ( strncmp(name, "module@", strlen("module@")) == 0 ) { > + > + if ( fdt_node_check_compatible(fdt, node, > + "xen,multiboot-module" ) != 0 ) > + early_panic("%s not a compatible module node\n", name); > + > + nr = simple_strtol(name + strlen("module@"), NULL, 10); > + if ( nr <= 0 ) > + early_panic("Invalid module number %d\n", nr); > + > + if ( nr > NR_MODULES ) > + early_panic("too many modules %d > %d\n", nr, NR_MODULES); > + if ( nr > nr_modules ) > + nr_modules = nr; > + > + mod = &early_info.modules.module[nr]; > + > + prop = fdt_get_property(fdt, node, "start", NULL); > + if ( !prop ) > + early_panic("no start for module %d\n", nr); > + > + cell = (const u32 *)prop->data; > + device_tree_get_reg(&cell, address_cells, size_cells, > + &mod->start, &size); This get_reg returns a start + size -- can/should we encode the module as one of these rather than encdong start + end separately and discarding the 'size' fields? > + > + prop = fdt_get_property(fdt, node, "end", NULL); > + if ( !prop ) > + early_panic("no end for module %d\n", nr); > + > + cell = (const u32 *)prop->data; > + device_tree_get_reg(&cell, address_cells, size_cells, > + &mod->size, &size); > + mod->size -= mod->start; > + > + prop = fdt_get_property(fdt, node, "bootargs", &len); > + if ( prop ) > + { > + if ( len > sizeof(mod->cmdline) ) > + early_panic("module %d command line too long\n", nr); > + > + safe_strcpy(mod->cmdline, prop->data); > + } > + else > + mod->cmdline[0] = 0; > + } > + } > + > + for ( nr = 1 ; nr < nr_modules ; nr++ ) > + { > + mod = &early_info.modules.module[nr]; > + if ( !mod->start || !mod->size ) > + early_panic("module %d missing / invalid\n", nr); > + } > + > + 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 +309,8 @@ 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..c383677 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 +27,21 @@ struct dt_mem_info { > struct membank bank[NR_MEM_BANKS]; > }; > > +struct dt_mb_module { > + paddr_t start; > + paddr_t size; > + char cmdline[1024]; > +}; > + > +struct dt_module_info { > + int nr_mods; > + /* Module 0 is Xen itself, followed by the provided modules-proper */ > + struct dt_mb_module module[NR_MODULES + 1]; > +}; > + > 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 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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