diff options
| -rw-r--r-- | arch/x86/boot/main.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c index 22ca62ba40c..7828da5cfd0 100644 --- a/arch/x86/boot/main.c +++ b/arch/x86/boot/main.c @@ -100,20 +100,32 @@ static void set_bios_mode(void) #endif } -void main(void) +static void init_heap(void) { - /* First, copy the boot header into the "zeropage" */ - copy_boot_params(); + char *stack_end; - /* End of heap check */ if (boot_params.hdr.loadflags & CAN_USE_HEAP) { - heap_end = (char *)(boot_params.hdr.heap_end_ptr - +0x200-STACK_SIZE); + asm("leal %P1(%%esp),%0" + : "=r" (stack_end) : "i" (-STACK_SIZE)); + + heap_end = (char *) + ((size_t)boot_params.hdr.heap_end_ptr + 0x200); + if (heap_end > stack_end) + heap_end = stack_end; } else { /* Boot protocol 2.00 only, no heap available */ puts("WARNING: Ancient bootloader, some functionality " "may be limited!\n"); } +} + +void main(void) +{ + /* First, copy the boot header into the "zeropage" */ + copy_boot_params(); + + /* End of heap check */ + init_heap(); /* Make sure we have all the proper CPU support */ if (validate_cpu()) { |