x86-32: use brk segment for allocating initial kernel pagetable

Impact: use new interface instead of previous ad hoc implementation

Rather than having special purpose init_pg_table_start/end variables
to delimit the kernel pagetable built by head_32.S, just use the brk
mechanism to extend the bss for the new pagetable.

This patch removes init_pg_table_start/end and pg0, defines __brk_base
(which is page-aligned and immediately follows _end), initializes
the brk region to start there, and uses it for the 32-bit pagetable.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 0 insertions, 3 deletions

diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 29f1095b0849..3f8579f8d42c 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -29,9 +29,6 @@ void __init i386_start_kernel(void)
                 reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
         }
 #endif
-        reserve_early(init_pg_tables_start, init_pg_tables_end,
-                        "INIT_PG_TABLE");
-
         reserve_ebda_region();
 
         /*