diff options
| -rw-r--r-- | docs/misc/arm/device-tree/booting.txt | 28 | ||||
| -rw-r--r-- | xen/arch/arm/domain_build.c | 15 | ||||
| -rw-r--r-- | xen/common/device_tree.c | 7 |
3 files changed, 44 insertions, 6 deletions
diff --git a/docs/misc/arm/device-tree/booting.txt b/docs/misc/arm/device-tree/booting.txt index 94cd3f18a4..08ed775185 100644 --- a/docs/misc/arm/device-tree/booting.txt +++ b/docs/misc/arm/device-tree/booting.txt @@ -1,3 +1,6 @@ +Dom0 kernel and ramdisk modules +================================ + Xen is passed the dom0 kernel and initrd via a reference in the /chosen node of the device tree. @@ -22,4 +25,27 @@ properties: - bootargs (optional) - Command line associated with this module + Command line associated with this module. This is deprecated and should + be replaced by the bootargs variations described below. + + +Command lines +============= + +Xen also checks for properties directly under /chosen to find suitable command +lines for Xen and Dom0. The logic is the following: + + - If xen,xen-bootargs is present, it will be used for Xen. + - If xen,dom0-bootargs is present, it will be used for Dom0. + - If xen,xen-bootargs is _not_ present, but xen,dom0-bootargs is, + bootargs will be used for Xen. + - If no Xen specific properties are present, bootargs is for Dom0. + - If xen,xen-bootargs is present, but xen,dom0-bootargs is missing, + bootargs will be used for Dom0. + +Most of these cases is to make booting with Xen-unaware bootloaders easier. +For those you would hardcode the Xen commandline in the DTB under +/chosen/xen,xen-bootargs and would let the bootloader set the Dom0 command +line by writing bootargs (as for native Linux). +A Xen-aware bootloader would set xen,xen-bootargs for Xen, xen,dom0-bootargs +for Dom0 and bootargs for native Linux. diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 82003c19fe..40af876474 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -146,6 +146,7 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo, const char *bootargs = NULL; const struct dt_property *pp; int res = 0; + int had_dom0_bootargs = 0; if ( early_info.modules.nr_mods >= MOD_KERNEL && early_info.modules.module[MOD_KERNEL].cmdline[0] ) @@ -162,15 +163,21 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo, * * * remember xen,dom0-bootargs if we don't already have * bootargs (from module #1, above). - * * remove bootargs and xen,dom0-bootargs. + * * remove bootargs, xen,dom0-bootargs and xen,xen-bootargs. */ if ( dt_node_path_is_equal(np, "/chosen") ) { - if ( dt_property_name_is_equal(pp, "bootargs") ) + if ( dt_property_name_is_equal(pp, "xen,xen-bootargs") ) + continue; + if ( dt_property_name_is_equal(pp, "xen,dom0-bootargs") ) + { + had_dom0_bootargs = 1; + bootargs = pp->value; continue; - else if ( dt_property_name_is_equal(pp, "xen,dom0-bootargs") ) + } + if ( dt_property_name_is_equal(pp, "bootargs") ) { - if ( !bootargs ) + if ( !bootargs && !had_dom0_bootargs ) bootargs = pp->value; continue; } diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c index ee58c52b2b..0ece2499ad 100644 --- a/xen/common/device_tree.c +++ b/xen/common/device_tree.c @@ -261,7 +261,12 @@ const char *device_tree_bootargs(const void *fdt) if ( node < 0 ) return NULL; - prop = fdt_get_property(fdt, node, "bootargs", NULL); + prop = fdt_get_property(fdt, node, "xen,xen-bootargs", NULL); + if ( prop == NULL ) + { + if (fdt_get_property(fdt, node, "xen,dom0-bootargs", NULL)) + prop = fdt_get_property(fdt, node, "bootargs", NULL); + } if ( prop == NULL ) return NULL; |