Display fallback message in case poweroff fails (contributed by Feiran 'Fam' Zheng)

diff --git a/kernel/arch/i386/klib16.S b/kernel/arch/i386/klib16.S
index 57c2ea2bfe3106650091c5d74d6f2bb64270384c..eefd421601a4f15799106daca29f5fff093eabae 100644 (file)
--- a/kernel/arch/i386/klib16.S
+++ b/kernel/arch/i386/klib16.S
@@ -54,18 +54,41 @@ gate_A20:
        mov     $0x5301,%ax
        mov     $0x0,%bx
        int     0x15
+       jc      apm_err
        
        /* Enable power management */
        mov     $0x5308,%ax
        mov     $0x1,%bx
        mov     $0x1,%cx
        int     0x15
+       jc      apm_err
        
        /* Set power state to off */
        mov     $0x5307,%ax
        mov     $0x01,%bx
        mov     $0x3,%cx
        int     0x15
+       jc      apm_err
+0:     hlt
+       jmp     0b
+       
+poweroff_msg:
+.ascii "You can poweroff the machine safely now"
+poweroff_msg_end:
+#define POWEROFF_MSG_LEN       (poweroff_msg_end-poweroff_msg)
+apm_err:
+       /* If APM can't perform the shutdown, print something to inform */
+       mov     $0x02, %ax      /* clear screen */
+       int     $0x10
+       
+       mov     $(BIOS_POWEROFF_ENTRY >> 4), %ax
+       mov     %ax, %es
+       mov     $0x1301, %ax
+       mov     $0x07, %bx
+       mov     $POWEROFF_MSG_LEN, %cx
+       mov     $0x0300, %dx
+       mov     $(poweroff_msg - _poweroff16), %bp
+       int     $0x10
 0:     hlt
        jmp     0b