[PATCH V3 12/15] Add efi_arch_use_config_file() function to control use of config file

[Roy Franz <roy.franz@linaro.org>]

The x86 EFI build of XEN always uses a configuration file to load modules, but
the ARM version can either use a config file to specify the modules, or be
loaded by GRUB in which case GRUB loads the modules and adds them to the DTB
that is passed to XEN.  Add the efi_arch_use_config_file() to indicate if a
configuration file is required.  For x86, this will always be true.  ARM will
examine the DTB passed via EFI configuration table (if any), and if it contains
module information will use that that not use the configuration file at all.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
---
 xen/common/efi/boot.c          | 169 +++++++++++++++++++++--------------------
 xen/include/asm-x86/efi-boot.h |   4 +
 2 files changed, 90 insertions(+), 83 deletions(-)

diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 1630dde..226189d 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -574,8 +574,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     EFI_SHIM_LOCK_PROTOCOL *shim_lock;
     EFI_GRAPHICS_OUTPUT_PROTOCOL *gop = NULL;
     EFI_GRAPHICS_OUTPUT_MODE_INFORMATION *mode_info;
-    EFI_FILE_HANDLE dir_handle;
-    union string section = { NULL }, name, file_name, cfg_file_name = {NULL};
+    union string section = { NULL }, name = { NULL }, file_name, cfg_file_name = {NULL};
     bool_t base_video = 0;
     UINT32 mmap_desc_ver = 0;
     UINTN mmap_size, mmap_desc_size, mmap_key = 0;
@@ -594,9 +593,6 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
 
     efi_arch_load_addr_check(loaded_image);
 
-    /* Get the file system interface. */
-    dir_handle = get_parent_handle(loaded_image, &file_name.w);
-
     argc = get_argv(0, NULL, loaded_image->LoadOptions,
                     loaded_image->LoadOptionsSize, &options);
     if ( argc > 0 &&
@@ -688,104 +684,111 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
     if ( EFI_ERROR(status) )
         gop = NULL;
 
-    /* Read and parse the config file. */
-    if ( !cfg_file_name.w )
+    if ( efi_arch_use_config_file(SystemTable) )
     {
-        CHAR16 *tail;
+        EFI_FILE_HANDLE dir_handle;
 
-        while ( (tail = point_tail(file_name.w)) != NULL )
+        /* Get the file system interface. */
+        dir_handle = get_parent_handle(loaded_image, &file_name.w);
+        /* Read and parse the config file. */
+        if ( !cfg_file_name.w )
         {
-            wstrcpy(tail, L".cfg");
-            if ( read_file(dir_handle, &cfg, w2s(&file_name)) )
-                break;
-            *tail = 0;
+            CHAR16 *tail;
+
+            while ( (tail = point_tail(file_name.w)) != NULL )
+            {
+                wstrcpy(tail, L".cfg");
+                if ( read_file(dir_handle, &cfg, w2s(&file_name)) )
+                    break;
+                *tail = 0;
+            }
+            if ( !tail )
+                blexit(L"No configuration file found.");
+            PrintStr(L"Using configuration file '");
+            s2w(&file_name);
+            PrintStr(file_name.w);
+            PrintStr(L"'\r\n");
+            efi_bs->FreePool(file_name.w);
         }
-        if ( !tail )
-            blexit(L"No configuration file found.");
-        PrintStr(L"Using configuration file '");
-        s2w(&file_name);
-        PrintStr(file_name.w);
-        PrintStr(L"'\r\n");
-        efi_bs->FreePool(file_name.w);
-    }
-    else if ( !read_file(dir_handle, &cfg, w2s(&cfg_file_name)) )
-        blexit(L"Configuration file not found.");
-    pre_parse(&cfg);
+        else if ( !read_file(dir_handle, &cfg, w2s(&cfg_file_name)) )
+            blexit(L"Configuration file not found.");
+        pre_parse(&cfg);
 
-    if ( section.w )
-        w2s(&section);
-    else
-        section.s = get_value(&cfg, "global", "default");
+        if ( section.w )
+            w2s(&section);
+        else
+            section.s = get_value(&cfg, "global", "default");
 
-    for ( ; ; )
-    {
-        name.s = get_value(&cfg, section.s, "kernel");
-        if ( name.s )
-            break;
-        name.s = get_value(&cfg, "global", "chain");
-        if ( !name.s )
-            break;
-        efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
-        cfg.addr = 0;
-        if ( !read_file(dir_handle, &cfg, name.s) )
+        for ( ; ; )
         {
-            PrintStr(L"Chained configuration file '");
-            PrintStr(name.w);
+            name.s = get_value(&cfg, section.s, "kernel");
+            if ( name.s )
+                break;
+            name.s = get_value(&cfg, "global", "chain");
+            if ( !name.s )
+                break;
+            efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
+            cfg.addr = 0;
+            if ( !read_file(dir_handle, &cfg, name.s) )
+            {
+                PrintStr(L"Chained configuration file '");
+                PrintStr(name.w);
+                efi_bs->FreePool(name.w);
+                blexit(L"'not found.");
+            }
+            pre_parse(&cfg);
             efi_bs->FreePool(name.w);
-            blexit(L"'not found.");
         }
-        pre_parse(&cfg);
-        efi_bs->FreePool(name.w);
-    }
-    if ( !name.s )
-        blexit(L"No Dom0 kernel image specified.");
-
-    efi_arch_cfg_file(dir_handle, section.s);
+        if ( !name.s )
+            blexit(L"No Dom0 kernel image specified.");
 
-    read_file(dir_handle, &kernel, name.s);
+        efi_arch_cfg_file(dir_handle, section.s);
 
-    if ( !EFI_ERROR(efi_bs->LocateProtocol(&shim_lock_guid, NULL,
-                    (void **)&shim_lock)) &&
-         (status = shim_lock->Verify(kernel.ptr, kernel.size)) != EFI_SUCCESS )
+        read_file(dir_handle, &kernel, name.s);
+        if ( !EFI_ERROR(efi_bs->LocateProtocol(&shim_lock_guid, NULL,
+                                               (void **)&shim_lock)) &&
+             (status = shim_lock->Verify(kernel.ptr, kernel.size)) != EFI_SUCCESS )
         PrintErrMesg(L"Dom0 kernel image could not be verified", status);
 
-    name.s = get_value(&cfg, section.s, "ramdisk");
-    if ( name.s )
-    {
-        read_file(dir_handle, &ramdisk, name.s);
-    }
+        name.s = get_value(&cfg, section.s, "ramdisk");
+        if ( name.s )
+        {
+            read_file(dir_handle, &ramdisk, name.s);
+        }
 
-    name.s = get_value(&cfg, section.s, "xsm");
-    if ( name.s )
-    {
-        read_file(dir_handle, &xsm, name.s);
-    }
+        name.s = get_value(&cfg, section.s, "xsm");
+        if ( name.s )
+        {
+            read_file(dir_handle, &xsm, name.s);
+        }
 
-    cols = rows = depth = 0;
-    if ( !base_video )
-    {
-        name.cs = get_value(&cfg, section.s, "video");
-        if ( !name.cs )
-            name.cs = get_value(&cfg, "global", "video");
-        if ( name.cs && !strncmp(name.cs, "gfx-", 4) )
+        cols = rows = depth = 0;
+        if ( !base_video )
         {
-            cols = simple_strtoul(name.cs + 4, &name.cs, 10);
-            if ( *name.cs == 'x' )
-                rows = simple_strtoul(name.cs + 1, &name.cs, 10);
-            if ( *name.cs == 'x' )
-                depth = simple_strtoul(name.cs + 1, &name.cs, 10);
-            if ( *name.cs )
-                cols = rows = depth = 0;
+            name.cs = get_value(&cfg, section.s, "video");
+            if ( !name.cs )
+                name.cs = get_value(&cfg, "global", "video");
+            if ( name.cs && !strncmp(name.cs, "gfx-", 4) )
+            {
+                cols = simple_strtoul(name.cs + 4, &name.cs, 10);
+                if ( *name.cs == 'x' )
+                    rows = simple_strtoul(name.cs + 1, &name.cs, 10);
+                if ( *name.cs == 'x' )
+                    depth = simple_strtoul(name.cs + 1, &name.cs, 10);
+                if ( *name.cs )
+                    cols = rows = depth = 0;
+            }
         }
-    }
+        name.s = get_value(&cfg, section.s, "options");
 
-    name.s = get_value(&cfg, section.s, "options");
-    efi_arch_handle_cmdline(argc ? *argv : NULL, options, name.s);
+        efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
+        cfg.addr = 0;
 
-    efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
-    cfg.addr = 0;
+        dir_handle->Close(dir_handle);
+
+        efi_arch_handle_cmdline(argc ? *argv : NULL, options, name.s);
+    }
 
-    dir_handle->Close(dir_handle);
     efi_arch_edd();
 
     /* XXX Collect EDID info. */
diff --git a/xen/include/asm-x86/efi-boot.h b/xen/include/asm-x86/efi-boot.h
index d7c6abc..1bd3545 100644
--- a/xen/include/asm-x86/efi-boot.h
+++ b/xen/include/asm-x86/efi-boot.h
@@ -1058,3 +1058,7 @@ static void __init efi_arch_load_addr_check(EFI_LOADED_IMAGE *loaded_image)
         blexit(L"Xen must be loaded at a 2Mb boundary.");
     trampoline_xen_phys_start = xen_phys_start;
 }
+static __init bool_t efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
+{
+    return 1; /* x86 always uses a config file */
+}
-- 
2.1.0.rc1