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arm: clear highly mapped kernel bss

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. added bss range values for the high (paged) kernel and
	  clear it in pre_init
	. this changes the meaning of the current _edata end _end in the
	  pre_init phase to mean: highly mapped bss; and the new symbols
	  _kern_unpaged_edata ... _kern_unpaged_edata to mean directly
	  mapped (pre_init) bss. This was previously _edata and _end.
	. added a sanity check in kmain (ben@)

The values can be verified by:

${CROSS_TOOLS}/arm-elf32-minix-objdump -xD ${OBJ}/kernel/kernel

Signed-off-by: Jan Kobler <eng1@koblersystems.de>
This commit is contained in:
Jan Kobler 2014-06-03 15:51:55 +02:00 committed by Lionel Sambuc
parent f80046feea
commit 29fe671680
3 changed files with 16 additions and 3 deletions
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8
kernel/arch/earm/kernel.lds
View file

@ -16,11 +16,10 @@ SECTIONS
.unpaged_text ALIGN(4096) : { unpaged_*.o(.text) }
.unpaged_data ALIGN(4096) : { unpaged_*.o(.data .rodata*) }
__k_unpaged__kern_unpaged__edata = .;
__k_unpaged__edata = .;
__k_unpaged__kern_unpaged_edata = .;
.unpaged_bss ALIGN(4096) : { unpaged_*.o(.bss COMMON) }
__k_unpaged__kern_unpaged_end = .;
__k_unpaged__end = .;
. += _kern_offset;
@ -34,12 +33,15 @@ SECTIONS
.data ALIGN(4096) : AT(ADDR(.data) - _kern_offset) { *(.data .rodata* ) }
. = ALIGN(4096);
_edata = .;
__k_unpaged__edata = . - _kern_offset;
.bss ALIGN(4096) : AT(ADDR(.bss) - _kern_offset) { *(.bss* COMMON)
__k_unpaged__kern_size = . - _kern_vir_base;
_kern_size = __k_unpaged__kern_size;
. += 4096;
}
_end = .;
__k_unpaged__end = . - _kern_offset;
/DISCARD/ :
{

6
kernel/arch/earm/pre_init.c
View file

@ -37,9 +37,14 @@ static void setup_mbi(multiboot_info_t *mbi, char *bootargs);
/* Kernel may use memory */
int kernel_may_alloc = 1;
/* kernel bss */
extern u32_t _edata;
extern u32_t _end;
/* kernel unpaged bss */
extern char _kern_unpaged_edata;
extern char _kern_unpaged_end;
/**
*
* The following function combines a few things together
@ -374,6 +379,7 @@ kinfo_t *pre_init(int argc, char **argv)
/* Clear BSS */
memset(&_edata, 0, (u32_t)&_end - (u32_t)&_edata);
memset(&_kern_unpaged_edata, 0, (u32_t)&_kern_unpaged_end - (u32_t)&_kern_unpaged_edata);
/* we get called in a c like fashion where the first arg
* is the program name (load address) and the rest are

5
kernel/main.c
View file

@ -123,6 +123,11 @@ void kmain(kinfo_t *local_cbi)
struct boot_image *ip; /* boot image pointer */
register struct proc *rp; /* process pointer */
register int i, j;
static int bss_test;
/* bss sanity check */
assert(bss_test == 0);
bss_test = 1;
/* save a global copy of the boot parameters */
memcpy(&kinfo, local_cbi, sizeof(kinfo));