The patch from Neil Turton _realy_ fixes the reboot problem !
I checked it on a machine that (besides Linux) even Windows'95 couldn't
reboot. I modified Neil's patch, so that the kernel now can understand
a boot commandline parameter:
reboot=cold
So, people with reboot problems can at least have a cold reboot.
It would be realy good to have it in the 2.0.x kernel.
On 20 Sep 1996, Neil Turton wrote:
> .... Also, I have had this problem
> and managed to make it go away by doing a cold software reset.
> [ ... ]
YES Neil, that did the job :-)
Below the modified patch from Neil, fits into 2.0.21.
Hans
<lermen@fgan.de>
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--- linux/init/main.c.old Sat Sep 21 00:38:41 1996
+++ linux/init/main.c Sat Sep 21 19:13:46 1996
@@ -98,6 +98,7 @@
extern void ppa_setup(char *str, int *ints);
extern void scsi_luns_setup(char *str, int *ints);
extern void sound_setup(char *str, int *ints);
+extern void reboot_setup(char *str, int *ints);
#ifdef CONFIG_CDU31A
extern void cdu31a_setup(char *str, int *ints);
#endif CONFIG_CDU31A
@@ -417,5 +418,6 @@
{ "baycom=", baycom_setup },
#endif
+ { "reboot=", reboot_setup },
{ 0, 0 }
};
--- linux/arch/i386/kernel/process.c.old Sat Sep 21 00:17:18 1996
+++ linux/arch/i386/kernel/process.c Sat Sep 21 19:13:39 1996
@@ -182,6 +182,13 @@
* and if it doesn't work, we do some other stupid things.
*/
static long no_idt[2] = {0, 0};
+static int reboot_mode = 0;
+
+void reboot_setup(char *str, int *ints)
+{
+ if (str[0] == 'c' /* cold */) reboot_mode = 1;
+ else reboot_mode = 0;
+}
static inline void kb_wait(void)
{
@@ -199,7 +206,7 @@
sti();
/* rebooting needs to touch the page at absolute addr 0 */
pg0[0] = 7;
- *((unsigned short *)0x472) = 0x1234;
+ *((unsigned short *)0x472) = reboot_mode ? 0 : 0x1234;
for (;;) {
for (i=0; i<100; i++) {
kb_wait();
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