summaryrefslogtreecommitdiff
path: root/arch/alpha/kernel/head.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/alpha/kernel/head.S')
-rw-r--r--arch/alpha/kernel/head.S99
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/alpha/kernel/head.S b/arch/alpha/kernel/head.S
new file mode 100644
index 000000000000..4ca2e404708a
--- /dev/null
+++ b/arch/alpha/kernel/head.S
@@ -0,0 +1,99 @@
+/*
+ * alpha/boot/head.S
+ *
+ * initial boot stuff.. At this point, the bootloader has already
+ * switched into OSF/1 PAL-code, and loaded us at the correct address
+ * (START_ADDR). So there isn't much left for us to do: just set up
+ * the kernel global pointer and jump to the kernel entry-point.
+ */
+
+#include <linux/config.h>
+#include <asm/system.h>
+#include <asm/asm_offsets.h>
+
+.globl swapper_pg_dir
+.globl _stext
+swapper_pg_dir=SWAPPER_PGD
+
+ .set noreorder
+ .globl __start
+ .ent __start
+_stext:
+__start:
+ .prologue 0
+ br $27,1f
+1: ldgp $29,0($27)
+ /* We need to get current_task_info loaded up... */
+ lda $8,init_thread_union
+ /* ... and find our stack ... */
+ lda $30,0x4000 - SIZEOF_PT_REGS($8)
+ /* ... and then we can start the kernel. */
+ jsr $26,start_kernel
+ call_pal PAL_halt
+ .end __start
+
+#ifdef CONFIG_SMP
+ .align 3
+ .globl __smp_callin
+ .ent __smp_callin
+ /* On entry here from SRM console, the HWPCB of the per-cpu
+ slot for this processor has been loaded. We've arranged
+ for the UNIQUE value for this process to contain the PCBB
+ of the target idle task. */
+__smp_callin:
+ .prologue 1
+ ldgp $29,0($27) # First order of business, load the GP.
+
+ call_pal PAL_rduniq # Grab the target PCBB.
+ mov $0,$16 # Install it.
+ call_pal PAL_swpctx
+
+ lda $8,0x3fff # Find "current".
+ bic $30,$8,$8
+
+ jsr $26,smp_callin
+ call_pal PAL_halt
+ .end __smp_callin
+#endif /* CONFIG_SMP */
+
+ #
+ # The following two functions are needed for supporting SRM PALcode
+ # on the PC164 (at least), since that PALcode manages the interrupt
+ # masking, and we cannot duplicate the effort without causing problems
+ #
+
+ .align 3
+ .globl cserve_ena
+ .ent cserve_ena
+cserve_ena:
+ .prologue 0
+ bis $16,$16,$17
+ lda $16,52($31)
+ call_pal PAL_cserve
+ ret ($26)
+ .end cserve_ena
+
+ .align 3
+ .globl cserve_dis
+ .ent cserve_dis
+cserve_dis:
+ .prologue 0
+ bis $16,$16,$17
+ lda $16,53($31)
+ call_pal PAL_cserve
+ ret ($26)
+ .end cserve_dis
+
+ #
+ # It is handy, on occasion, to make halt actually just loop.
+ # Putting it here means we dont have to recompile the whole
+ # kernel.
+ #
+
+ .align 3
+ .globl halt
+ .ent halt
+halt:
+ .prologue 0
+ call_pal PAL_halt
+ .end halt