[PATCH v5 09/44] x86/boot: introduce boot module types

[Daniel P. Smith]

This commit introduces module types of xen, kernel, and ramdisk to allow boot
module detect code to tag the purpose of a boot module. This reduces the need
for hard coded order assumptions and global variables to be used by consumers
of boot modules, such as domain construction.

Signed-off-by: Daniel P. Smith <dpsm...@apertussolutions.com>
---
 xen/arch/x86/include/asm/bootinfo.h | 9 +++++++++
 xen/arch/x86/setup.c                | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/xen/arch/x86/include/asm/bootinfo.h 
b/xen/arch/x86/include/asm/bootinfo.h
index c7e6b4ebf0da..6941a8975ea6 100644
--- a/xen/arch/x86/include/asm/bootinfo.h
+++ b/xen/arch/x86/include/asm/bootinfo.h
@@ -14,6 +14,14 @@
 /* Max number of boot modules a bootloader can provide in addition to Xen */
 #define MAX_NR_BOOTMODS 63
 
+/* Boot module binary type / purpose */
+enum bootmod_type {
+    BOOTMOD_UNKNOWN,
+    BOOTMOD_XEN,
+    BOOTMOD_KERNEL,
+    BOOTMOD_RAMDISK,
+};
+
 struct boot_module {
     /* Transitionary only */
     module_t *mod;
@@ -22,6 +30,7 @@ struct boot_module {
      * reserved, into which it will be decompressed.
      */
     unsigned long headroom;
+    enum bootmod_type type;
 };
 
 /*
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index ba4bee6b93af..69c45f115523 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -311,6 +311,10 @@ static struct boot_info __init 
*multiboot_fill_boot_info(unsigned long mbi_p)
     for ( i = 0; i <= bi->nr_modules; i++ )
         bi->mods[i].mod = &mods[i];
 
+    /* map the last mb module for xen entry */
+    bi->mods[bi->nr_modules].type = BOOTMOD_XEN;
+    bi->mods[bi->nr_modules].mod = &mods[bi->nr_modules];
+
     return bi;
 }
 
@@ -1171,6 +1175,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long 
mbi_p)
 
     bitmap_fill(module_map, bi->nr_modules);
     __clear_bit(0, module_map); /* Dom0 kernel is always first */
+    bi->mods[0].type = BOOTMOD_KERNEL;
 
     if ( pvh_boot )
     {
@@ -2058,6 +2063,7 @@ void asmlinkage __init noreturn __start_xen(unsigned long 
mbi_p)
            cpu_has_nx ? "" : "not ");
 
     initrdidx = find_first_bit(module_map, bi->nr_modules);
+    bi->mods[initrdidx].type = BOOTMOD_RAMDISK;
     if ( bitmap_weight(module_map, bi->nr_modules) > 1 )
         printk(XENLOG_WARNING
                "Multiple initrd candidates, picking module #%u\n",
-- 
2.30.2