[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v6 1/2] arm/efi: Use dom0less configuration when using EFI boot



On Mon, 11 Oct 2021, Luca Fancellu wrote:
> This patch introduces the support for dom0less configuration
> when using UEFI boot on ARM, it permits the EFI boot to
> continue if no dom0 kernel is specified but at least one domU
> is found.
> 
> Introduce the new property "xen,uefi-binary" for device tree boot
> module nodes that are subnode of "xen,domain" compatible nodes.
> The property holds a string containing the file name of the
> binary that shall be loaded by the uefi loader from the filesystem.
> 
> Introduce a new call efi_check_dt_boot(...) called during EFI boot
> that checks for module to be loaded using device tree.
> Architectures that don't support device tree don't have to
> provide this function.
> 
> Update efi documentation about how to start a dom0less
> setup using UEFI
> 
> Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> Changes in v6:
> - change is_boot_module() to check for every multiboot,module
> instead of multiboot,{kernel,ramdisk,device-tree} (Julien), as
> a result of that remove the function and put the check inside of
> handle_module_node(...)
> Changes in v5:
> - Removed unneeded variable initialization
> - Fixed comment
> - Fixed error message for the absence of an initial domain kernel
> - changed efi_arch_check_dt_boot to efi_check_dt_boot and add
> a stub if CONFIG_HAS_DEVICE_TREE is not declared, updated commit
> message about the call introduction in the EFI boot flow.
> Changes in v4:
> - update uefi,cfg-load to xen,uefi-cfg-load in documentation
> - fixed comments and code style
> - changed variable name from dt_module_found to dt_modules_found
> in boot.c
> - removed stub efi_arch_check_dt_boot from x86 code because the
> architecture does not support DT, protected call with #ifdef
> in the common code.
> - add comment to explain the result from efi_arch_check_dt_boot
> just looking the common code
> - Add space before comment in boot.c
> - renamed uefi,binary property to xen,uefi-binary
> Changes in v3:
> - fixed documentation
> - fixed name len in strlcpy
> - fixed some style issues
> - closed filesystem handle before calling blexit
> - passed runtime errors up to the stack instead
> of calling blexit
> - renamed names and function to make them more
> general in prevision to load also Dom0 kernel
> and ramdisk from DT
> Changes in v2:
> - remove array of struct file
> - fixed some int types
> - Made the code use filesystem even when configuration
> file is skipped.
> - add documentation of uefi,binary in booting.txt
> - add documentation on how to boot all configuration
> for Xen using UEFI in efi.pandoc
> ---
>  docs/misc/arm/device-tree/booting.txt |  21 ++
>  docs/misc/efi.pandoc                  | 203 +++++++++++++++++
>  xen/arch/arm/efi/efi-boot.h           | 299 +++++++++++++++++++++++++-
>  xen/common/efi/boot.c                 |  39 +++-
>  4 files changed, 550 insertions(+), 12 deletions(-)
> 
> diff --git a/docs/misc/arm/device-tree/booting.txt 
> b/docs/misc/arm/device-tree/booting.txt
> index 352b0ec43a..7258e7e1ec 100644
> --- a/docs/misc/arm/device-tree/booting.txt
> +++ b/docs/misc/arm/device-tree/booting.txt
> @@ -190,6 +190,13 @@ The kernel sub-node has the following properties:
>  
>      Command line parameters for the guest kernel.
>  
> +- xen,uefi-binary (UEFI boot only)
> +
> +    String property that specifies the file name to be loaded by the UEFI 
> boot
> +    for this module. If this is specified, there is no need to specify the 
> reg
> +    property because it will be created by the UEFI stub on boot.
> +    This option is needed only when UEFI boot is used.
> +
>  The ramdisk sub-node has the following properties:
>  
>  - compatible
> @@ -201,6 +208,13 @@ The ramdisk sub-node has the following properties:
>      Specifies the physical address of the ramdisk in RAM and its
>      length.
>  
> +- xen,uefi-binary (UEFI boot only)
> +
> +    String property that specifies the file name to be loaded by the UEFI 
> boot
> +    for this module. If this is specified, there is no need to specify the 
> reg
> +    property because it will be created by the UEFI stub on boot.
> +    This option is needed only when UEFI boot is used.
> +
>  
>  Example
>  =======
> @@ -265,6 +279,13 @@ The dtb sub-node should have the following properties:
>      Specifies the physical address of the device tree binary fragment
>      RAM and its length.
>  
> +- xen,uefi-binary (UEFI boot only)
> +
> +    String property that specifies the file name to be loaded by the UEFI 
> boot
> +    for this module. If this is specified, there is no need to specify the 
> reg
> +    property because it will be created by the UEFI stub on boot.
> +    This option is needed only when UEFI boot is used.
> +
>  As an example:
>  
>          module@0xc000000 {
> diff --git a/docs/misc/efi.pandoc b/docs/misc/efi.pandoc
> index ed85351541..876cd55005 100644
> --- a/docs/misc/efi.pandoc
> +++ b/docs/misc/efi.pandoc
> @@ -167,3 +167,206 @@ sbsign \
>       --output xen.signed.efi \
>       xen.unified.efi
>  ```
> +
> +## UEFI boot and dom0less on ARM
> +
> +Dom0less feature is supported by ARM and it is possible to use it when Xen is
> +started as an EFI application.
> +The way to specify the domU domains is by Device Tree as specified in the
> +[dom0less](dom0less.html) documentation page under the "Device Tree
> +configuration" section, but instead of declaring the reg property in the boot
> +module, the user must specify the "xen,uefi-binary" property containing the 
> name
> +of the binary file that has to be loaded in memory.
> +The UEFI stub will load the binary in memory and it will add the reg property
> +accordingly.
> +
> +An example here:
> +
> +domU1 {
> +     #address-cells = <1>;
> +     #size-cells = <1>;
> +     compatible = "xen,domain";
> +     memory = <0 0x20000>;
> +     cpus = <1>;
> +     vpl011;
> +
> +     module@1 {
> +             compatible = "multiboot,kernel", "multiboot,module";
> +             xen,uefi-binary = "vmlinuz-3.0.31-0.4-xen";
> +             bootargs = "console=ttyAMA0";
> +     };
> +     module@2 {
> +             compatible = "multiboot,ramdisk", "multiboot,module";
> +             xen,uefi-binary = "initrd-3.0.31-0.4-xen";
> +     };
> +     module@3 {
> +             compatible = "multiboot,ramdisk", "multiboot,module";
> +             xen,uefi-binary = "passthrough.dtb";
> +     };
> +};
> +
> +## How to boot different Xen setup using UEFI
> +
> +These are the different ways to boot a Xen system from UEFI:
> +
> + - Boot Xen and Dom0 (minimum required)
> + - Boot Xen and DomU(s) (true dom0less, only on ARM)
> + - Boot Xen, Dom0 and DomU(s) (only on ARM)
> +
> +### Boot Xen and Dom0
> +
> +This configuration can be started using the Xen configuration file in the
> +example above.
> +
> +### Boot Xen and DomU(s)
> +
> +This configuration needs the domU domain(s) specified in the /chosen node,
> +examples of how to do that are provided by the documentation about dom0less
> +and the example above shows how to use the "xen,uefi-binary" property to use 
> the
> +UEFI stub for module loading.
> +When adding DomU modules to device tree, also add the property
> +xen,uefi-cfg-load under chosen for Xen to load the Xen config file.
> +Otherwise, Xen will skip the config file and rely on device tree alone.
> +
> +Example 1 of how to boot a true dom0less configuration:
> +
> +Xen configuration file: skipped.
> +
> +Device tree:
> +
> +```
> +chosen {
> +     #size-cells = <0x1>;
> +     #address-cells = <0x1>;
> +     xen,xen-bootargs = "<Xen command line>"
> +
> +     domU1 {
> +             #size-cells = <0x1>;
> +             #address-cells = <0x1>;
> +             compatible = "xen,domain";
> +             cpus = <0x1>;
> +             memory = <0x0 0xc0000>;
> +             vpl011;
> +
> +             module@1 {
> +                     compatible = "multiboot,kernel", "multiboot,module";
> +                     xen,uefi-binary = "Image-domu1.bin";
> +                     bootargs = "console=ttyAMA0 root=/dev/ram0 rw";
> +             };
> +     };
> +     domU2 {
> +             #size-cells = <0x1>;
> +             #address-cells = <0x1>;
> +             compatible = "xen,domain";
> +             cpus = <0x1>;
> +             memory = <0x0 0x100000>;
> +             vpl011;
> +
> +             module@2 {
> +                     compatible = "multiboot,kernel", "multiboot,module";
> +                     xen,uefi-binary = "Image-domu2.bin";
> +                     bootargs = "console=ttyAMA0 root=/dev/ram0 rw";
> +             };
> +     };
> +};
> +```
> +
> +Example 2 of how to boot a true dom0less configuration:
> +
> +Xen configuration file:
> +
> +```
> +[global]
> +default=xen
> +
> +[xen]
> +options=<Xen command line>
> +dtb=<optional DTB>
> +```
> +
> +Device tree:
> +
> +```
> +chosen {
> +     #size-cells = <0x1>;
> +     #address-cells = <0x1>;
> +     xen,uefi-cfg-load;
> +
> +     domU1 {
> +             #size-cells = <0x1>;
> +             #address-cells = <0x1>;
> +             compatible = "xen,domain";
> +             cpus = <0x1>;
> +             memory = <0x0 0xc0000>;
> +             vpl011;
> +
> +             module@1 {
> +                     compatible = "multiboot,kernel", "multiboot,module";
> +                     xen,uefi-binary = "Image-domu1.bin";
> +                     bootargs = "console=ttyAMA0 root=/dev/ram0 rw";
> +             };
> +     };
> +     domU2 {
> +             #size-cells = <0x1>;
> +             #address-cells = <0x1>;
> +             compatible = "xen,domain";
> +             cpus = <0x1>;
> +             memory = <0x0 0x100000>;
> +             vpl011;
> +
> +             module@2 {
> +                     compatible = "multiboot,kernel", "multiboot,module";
> +                     xen,uefi-binary = "Image-domu2.bin";
> +                     bootargs = "console=ttyAMA0 root=/dev/ram0 rw";
> +             };
> +     };
> +};
> +```
> +
> +### Boot Xen, Dom0 and DomU(s)
> +
> +This configuration is a mix of the two configuration above, to boot this one
> +the configuration file must be processed so the /chosen node must have the
> +"xen,uefi-cfg-load" property.
> +
> +Here an example:
> +
> +Xen configuration file:
> +
> +```
> +[global]
> +default=xen
> +
> +[xen]
> +options=<Xen command line>
> +kernel=vmlinuz-3.0.31-0.4-xen [domain 0 command line options]
> +ramdisk=initrd-3.0.31-0.4-xen
> +dtb=<optional DTB>
> +```
> +
> +Device tree:
> +
> +```
> +chosen {
> +     #size-cells = <0x1>;
> +     #address-cells = <0x1>;
> +     xen,uefi-cfg-load;
> +
> +     domU1 {
> +             #size-cells = <0x1>;
> +             #address-cells = <0x1>;
> +             compatible = "xen,domain";
> +             cpus = <0x1>;
> +             memory = <0x0 0xc0000>;
> +             vpl011;
> +
> +             module@1 {
> +                     compatible = "multiboot,kernel", "multiboot,module";
> +                     xen,uefi-binary = "Image-domu1.bin";
> +                     bootargs = "console=ttyAMA0 root=/dev/ram0 rw";
> +             };
> +     };
> +};
> +```
> +
> +
> diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
> index a3e46453d4..f35e035b22 100644
> --- a/xen/arch/arm/efi/efi-boot.h
> +++ b/xen/arch/arm/efi/efi-boot.h
> @@ -8,9 +8,49 @@
>  #include <asm/setup.h>
>  #include <asm/smp.h>
>  
> +typedef struct {
> +    char *name;
> +    unsigned int name_len;
> +    EFI_PHYSICAL_ADDRESS addr;
> +    UINTN size;
> +} module_name;
> +
> +/*
> + * Binaries will be translated into bootmodules, the maximum number for them 
> is
> + * MAX_MODULES where we should remove a unit for Xen and one for Xen DTB
> + */
> +#define MAX_UEFI_MODULES (MAX_MODULES - 2)
> +static struct file __initdata module_binary;
> +static module_name __initdata modules[MAX_UEFI_MODULES];
> +static unsigned int __initdata modules_available = MAX_UEFI_MODULES;
> +static unsigned int __initdata modules_idx;
> +
> +#define ERROR_BINARY_FILE_NOT_FOUND (-1)
> +#define ERROR_ALLOC_MODULE_NO_SPACE (-1)
> +#define ERROR_ALLOC_MODULE_NAME     (-2)
> +#define ERROR_MISSING_DT_PROPERTY   (-3)
> +#define ERROR_RENAME_MODULE_NAME    (-4)
> +#define ERROR_SET_REG_PROPERTY      (-5)
> +#define ERROR_CHECK_MODULE_COMPAT   (-6)
> +#define ERROR_DT_MODULE_DOMU        (-1)
> +#define ERROR_DT_CHOSEN_NODE        (-2)
> +
>  void noreturn efi_xen_start(void *fdt_ptr, uint32_t fdt_size);
>  void __flush_dcache_area(const void *vaddr, unsigned long size);
>  
> +static int get_module_file_index(const char *name, unsigned int name_len);
> +static void PrintMessage(const CHAR16 *s);
> +static int allocate_module_file(EFI_FILE_HANDLE dir_handle,
> +                                const char *name,
> +                                unsigned int name_len);
> +static int handle_module_node(EFI_FILE_HANDLE dir_handle,
> +                              int module_node_offset,
> +                              int reg_addr_cells,
> +                              int reg_size_cells);
> +static int handle_dom0less_domain_node(EFI_FILE_HANDLE dir_handle,
> +                                       int domain_node);
> +static int efi_check_dt_boot(EFI_FILE_HANDLE dir_handle);
> +
>  #define DEVICE_TREE_GUID \
>  {0xb1b621d5, 0xf19c, 0x41a5, {0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 
> 0xe0}}
>  
> @@ -552,8 +592,254 @@ static void __init efi_arch_handle_module(const struct 
> file *file,
>                           kernel.size) < 0 )
>              blexit(L"Unable to set reg property.");
>      }
> -    else
> +    else if ( file != &module_binary )
> +        /*
> +         * If file is not a dom0 module file and it's not a domU module,
> +         * stop here.
> +         */
>          blexit(L"Unknown module type");
> +
> +    /*
> +     * modules_available is decremented here because for each dom0 file added
> +     * from the configuration file, there will be an additional bootmodule,
> +     * so the number of available slots will be decremented because there is 
> a
> +     * maximum amount of bootmodules that can be loaded.
> +     */
> +    modules_available--;
> +}
> +
> +/*
> + * This function checks for a binary previously loaded with a give name, it
> + * returns the index of the file in the modules array or a negative number 
> if no
> + * file with that name is found.
> + */
> +static int __init get_module_file_index(const char *name,
> +                                        unsigned int name_len)
> +{
> +    unsigned int i;
> +    int ret = ERROR_BINARY_FILE_NOT_FOUND;
> +
> +    for ( i = 0; i < modules_idx; i++ )
> +    {
> +        module_name *mod = &modules[i];
> +        if ( (mod->name_len == name_len) &&
> +             (strncmp(mod->name, name, name_len) == 0) )
> +        {
> +            ret = i;
> +            break;
> +        }
> +    }
> +    return ret;
> +}
> +
> +static void __init PrintMessage(const CHAR16 *s)
> +{
> +    PrintStr(s);
> +    PrintStr(newline);
> +}
> +
> +/*
> + * This function allocates a binary and keeps track of its name, it returns 
> the
> + * index of the file in the modules array or a negative number on error.
> + */
> +static int __init allocate_module_file(EFI_FILE_HANDLE dir_handle,
> +                                       const char *name,
> +                                       unsigned int name_len)
> +{
> +    module_name *file_name;
> +    union string module_name;
> +    int ret;
> +
> +    /*
> +     * Check if there is any space left for a module, the variable
> +     * modules_available is updated each time we use read_file(...)
> +     * successfully.
> +     */
> +    if ( !modules_available )
> +    {
> +        PrintMessage(L"No space left for modules");
> +        return ERROR_ALLOC_MODULE_NO_SPACE;
> +    }
> +
> +    module_name.cs = name;
> +    ret = modules_idx;
> +
> +    /* Save at this index the name of this binary */
> +    file_name = &modules[ret];
> +
> +    if ( efi_bs->AllocatePool(EfiLoaderData, (name_len + 1) * sizeof(char),
> +                              (void**)&file_name->name) != EFI_SUCCESS )
> +    {
> +        PrintMessage(L"Error allocating memory for module binary name");
> +        return ERROR_ALLOC_MODULE_NAME;
> +    }
> +
> +    /* Save name and length of the binary in the data structure */
> +    strlcpy(file_name->name, name, name_len + 1);
> +    file_name->name_len = name_len;
> +
> +    /* Load the binary in memory */
> +    read_file(dir_handle, s2w(&module_name), &module_binary, NULL);
> +
> +    /* Save address and size */
> +    file_name->addr = module_binary.addr;
> +    file_name->size = module_binary.size;
> +
> +    /* s2w(...) allocates some memory, free it */
> +    efi_bs->FreePool(module_name.w);
> +
> +    modules_idx++;
> +
> +    return ret;
> +}
> +
> +/*
> + * This function checks for the presence of the xen,uefi-binary property in 
> the
> + * module, if found it loads the binary as module and sets the right address
> + * for the reg property into the module DT node.
> + */
> +static int __init handle_module_node(EFI_FILE_HANDLE dir_handle,
> +                                     int module_node_offset,
> +                                     int reg_addr_cells,
> +                                     int reg_size_cells)
> +{
> +    const void *uefi_name_prop;
> +    char mod_string[24]; /* Placeholder for module@ + a 64-bit number + \0 */
> +    int uefi_name_len, file_idx, module_compat;
> +    module_name *file;
> +
> +    /* Check if the node is a multiboot,module otherwise return */
> +    module_compat = fdt_node_check_compatible(fdt, module_node_offset,
> +                                              "multiboot,module");
> +    if ( module_compat < 0 )
> +        /* Error while checking the compatible string */
> +        return ERROR_CHECK_MODULE_COMPAT;
> +
> +    if ( module_compat != 0 )
> +        /* Module is not a multiboot,module */
> +        return 0;
> +
> +    /* Read xen,uefi-binary property to get the file name. */
> +    uefi_name_prop = fdt_getprop(fdt, module_node_offset, "xen,uefi-binary",
> +                                 &uefi_name_len);
> +
> +    if ( !uefi_name_prop )
> +        /* Property not found */
> +        return 0;
> +
> +    file_idx = get_module_file_index(uefi_name_prop, uefi_name_len);
> +    if ( file_idx < 0 )
> +    {
> +        file_idx = allocate_module_file(dir_handle, uefi_name_prop,
> +                                        uefi_name_len);
> +        if ( file_idx < 0 )
> +            return file_idx;
> +    }
> +
> +    file = &modules[file_idx];
> +
> +    snprintf(mod_string, sizeof(mod_string), "module@%"PRIx64, file->addr);
> +
> +    /* Rename the module to be module@{address} */
> +    if ( fdt_set_name(fdt, module_node_offset, mod_string) < 0 )
> +    {
> +        PrintMessage(L"Unable to modify module node name.");
> +        return ERROR_RENAME_MODULE_NAME;
> +    }
> +
> +    if ( fdt_set_reg(fdt, module_node_offset, reg_addr_cells, reg_size_cells,
> +                     file->addr, file->size) < 0 )
> +    {
> +        PrintMessage(L"Unable to set module reg property.");
> +        return ERROR_SET_REG_PROPERTY;
> +    }
> +
> +    return 0;
> +}
> +
> +/*
> + * This function checks for boot modules under the domU guest domain node
> + * in the DT.
> + * Returns 0 on success, negative number on error.
> + */
> +static int __init handle_dom0less_domain_node(EFI_FILE_HANDLE dir_handle,
> +                                              int domain_node)
> +{
> +    int module_node, addr_cells, size_cells, len;
> +    const struct fdt_property *prop;
> +
> +    /* Get #address-cells and #size-cells from domain node */
> +    prop = fdt_get_property(fdt, domain_node, "#address-cells", &len);
> +    if ( !prop )
> +    {
> +        PrintMessage(L"#address-cells not found in domain node.");
> +        return ERROR_MISSING_DT_PROPERTY;
> +    }
> +
> +    addr_cells = fdt32_to_cpu(*((uint32_t *)prop->data));
> +
> +    prop = fdt_get_property(fdt, domain_node, "#size-cells", &len);
> +    if ( !prop )
> +    {
> +        PrintMessage(L"#size-cells not found in domain node.");
> +        return ERROR_MISSING_DT_PROPERTY;
> +    }
> +
> +    size_cells = fdt32_to_cpu(*((uint32_t *)prop->data));
> +
> +    /* Check for nodes compatible with multiboot,module inside this node */
> +    for ( module_node = fdt_first_subnode(fdt, domain_node);
> +          module_node > 0;
> +          module_node = fdt_next_subnode(fdt, module_node) )
> +    {
> +        int ret = handle_module_node(dir_handle, module_node, addr_cells,
> +                                        size_cells);
> +        if ( ret < 0 )
> +            return ret;
> +    }
> +
> +    return 0;
> +}
> +
> +/*
> + * This function checks for xen domain nodes under the /chosen node for 
> possible
> + * domU guests to be loaded.
> + * Returns the number of modules loaded or a negative number for error.
> + */
> +static int __init efi_check_dt_boot(EFI_FILE_HANDLE dir_handle)
> +{
> +    int chosen, node, addr_len, size_len;
> +    unsigned int i = 0;
> +
> +    /* Check for the chosen node in the current DTB */
> +    chosen = setup_chosen_node(fdt, &addr_len, &size_len);
> +    if ( chosen < 0 )
> +    {
> +        PrintMessage(L"Unable to setup chosen node");
> +        return ERROR_DT_CHOSEN_NODE;
> +    }
> +
> +    /* Check for nodes compatible with xen,domain under the chosen node */
> +    for ( node = fdt_first_subnode(fdt, chosen);
> +          node > 0;
> +          node = fdt_next_subnode(fdt, node) )
> +    {
> +        if ( !fdt_node_check_compatible(fdt, node, "xen,domain") )
> +        {
> +            /* Found a node with compatible xen,domain; handle this node. */
> +            if ( handle_dom0less_domain_node(dir_handle, node) < 0 )
> +                return ERROR_DT_MODULE_DOMU;
> +        }
> +    }
> +
> +    /* Free boot modules file names if any */
> +    for ( ; i < modules_idx; i++ )
> +    {
> +        /* Free boot modules binary names */
> +        efi_bs->FreePool(modules[i].name);
> +    }
> +
> +    return modules_idx;
>  }
>  
>  static void __init efi_arch_cpu(void)
> @@ -562,8 +848,19 @@ static void __init efi_arch_cpu(void)
>  
>  static void __init efi_arch_blexit(void)
>  {
> +    unsigned int i = 0;
> +
>      if ( dtbfile.need_to_free )
>          efi_bs->FreePages(dtbfile.addr, PFN_UP(dtbfile.size));
> +    /* Free boot modules file names if any */
> +    for ( ; i < modules_idx; i++ )
> +    {
> +        /* Free boot modules binary names */
> +        efi_bs->FreePool(modules[i].name);
> +        /* Free modules binaries */
> +        efi_bs->FreePages(modules[i].addr,
> +                          PFN_UP(modules[i].size));
> +    }
>      if ( memmap )
>          efi_bs->FreePool(memmap);
>  }
> diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> index 758f9d74d2..7879b93f93 100644
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -166,6 +166,13 @@ static void __init PrintErr(const CHAR16 *s)
>      StdErr->OutputString(StdErr, (CHAR16 *)s );
>  }
>  
> +#ifndef CONFIG_HAS_DEVICE_TREE
> +static inline int __init efi_check_dt_boot(EFI_FILE_HANDLE dir_handle)
> +{
> +    return 0;
> +}
> +#endif
> +
>  /*
>   * Include architecture specific implementation here, which references the
>   * static globals defined above.
> @@ -1136,6 +1143,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>      bool base_video = false;
>      const char *option_str;
>      bool use_cfg_file;
> +    int dt_modules_found;
> +    EFI_FILE_HANDLE dir_handle;
>  
>      __set_bit(EFI_BOOT, &efi_flags);
>      __set_bit(EFI_LOADER, &efi_flags);
> @@ -1216,9 +1225,11 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>  
>      efi_arch_relocate_image(0);
>  
> +    /* Get the file system interface. */
> +    dir_handle = get_parent_handle(loaded_image, &file_name);
> +
>      if ( use_cfg_file )
>      {
> -        EFI_FILE_HANDLE dir_handle;
>          UINTN depth, cols, rows, size;
>  
>          size = cols = rows = depth = 0;
> @@ -1229,9 +1240,6 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>  
>          gop = efi_get_gop();
>  
> -        /* Get the file system interface. */
> -        dir_handle = get_parent_handle(loaded_image, &file_name);
> -
>          /* Read and parse the config file. */
>          if ( read_section(loaded_image, L"config", &cfg, NULL) )
>              PrintStr(L"Using builtin config file\r\n");
> @@ -1285,14 +1293,12 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>              efi_bs->FreePool(name.w);
>          }
>  
> -        if ( !name.s )
> -            blexit(L"No Dom0 kernel image specified.");
> -
>          efi_arch_cfg_file_early(loaded_image, dir_handle, section.s);
>  
> -        option_str = split_string(name.s);
> +        option_str = name.s ? split_string(name.s) : NULL;
>  
> -        if ( !read_section(loaded_image, L"kernel", &kernel, option_str) )
> +        if ( !read_section(loaded_image, L"kernel", &kernel, option_str) &&
> +             name.s )
>          {
>              read_file(dir_handle, s2w(&name), &kernel, option_str);
>              efi_bs->FreePool(name.w);
> @@ -1361,12 +1367,23 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
> *SystemTable)
>          efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
>          cfg.addr = 0;
>  
> -        dir_handle->Close(dir_handle);
> -
>          if ( gop && !base_video )
>              gop_mode = efi_find_gop_mode(gop, cols, rows, depth);
>      }
>  
> +    /* Get the number of boot modules specified on the DT or an error (<0) */
> +    dt_modules_found = efi_check_dt_boot(dir_handle);
> +
> +    dir_handle->Close(dir_handle);
> +
> +    if ( dt_modules_found < 0 )
> +        /* efi_check_dt_boot throws some error */
> +        blexit(L"Error processing boot modules on DT.");
> +
> +    /* Check if at least one of Dom0 or DomU(s) is specified */
> +    if ( !dt_modules_found && !kernel.ptr )
> +        blexit(L"No initial domain kernel specified.");
> +
>      efi_arch_edd();
>  
>      /* XXX Collect EDID info. */
> -- 
> 2.17.1
> 



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.