[PATCH] Mini-OS: x86: zero out .bss segment at boot

[Juergen Gross <jgross@xxxxxxxx>]

The .bss segment should be zeroed at very early boot.

While adding the extern declaration of __bss_start for x86, make it
together with the other linker table defined section boundaries
common for all architectures.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 arch/x86/setup.c      | 2 ++
 include/arm/arch_mm.h | 1 -
 include/mm.h          | 2 ++
 include/x86/arch_mm.h | 1 -
 4 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/setup.c b/arch/x86/setup.c
index b27bbed7..3dddf4ad 100644
--- a/arch/x86/setup.c
+++ b/arch/x86/setup.c
@@ -184,6 +184,8 @@ arch_init(void *par)
 {
        static char hello[] = "Bootstrapping...\n";
 
+       memset(&__bss_start, 0, &_end - &__bss_start);
+
        hpc_init();
        (void)HYPERVISOR_console_io(CONSOLEIO_write, strlen(hello), hello);
 
diff --git a/include/arm/arch_mm.h b/include/arm/arch_mm.h
index 79d9e05b..335eb4ff 100644
--- a/include/arm/arch_mm.h
+++ b/include/arm/arch_mm.h
@@ -3,7 +3,6 @@
 
 typedef uint64_t paddr_t;
 
-extern char _text, _etext, _erodata, _edata, _end, __bss_start;
 extern int _boot_stack[];
 extern int _boot_stack_end[];
 extern uint32_t physical_address_offset;       /* Add this to a virtual 
address to get the physical address (wraps at 4GB) */
diff --git a/include/mm.h b/include/mm.h
index 4fc364ff..e02e080b 100644
--- a/include/mm.h
+++ b/include/mm.h
@@ -46,6 +46,8 @@
 #define round_pgdown(_p)  ((_p) & PAGE_MASK)
 #define round_pgup(_p)    (((_p) + (PAGE_SIZE - 1)) & PAGE_MASK)
 
+extern char _text, _etext, _erodata, _edata, _end, __bss_start;
+
 extern unsigned long nr_free_pages;
 
 extern unsigned long *mm_alloc_bitmap;
diff --git a/include/x86/arch_mm.h b/include/x86/arch_mm.h
index a1b975dc..6b398cef 100644
--- a/include/x86/arch_mm.h
+++ b/include/x86/arch_mm.h
@@ -225,7 +225,6 @@ extern unsigned long *phys_to_machine_mapping;
 #else
 extern pgentry_t page_table_base[];
 #endif
-extern char _text, _etext, _erodata, _edata, _end;
 extern unsigned long mfn_zero;
 static __inline__ maddr_t phys_to_machine(paddr_t phys)
 {
-- 
2.35.3