Changeset 1f12fab in mainline for kernel/arch/sparc32/src/userspace.c

Timestamp:

2013-10-07T20:00:34Z (11 years ago)

Author:

Jakub Klama <jakub.klama@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

a73ebf0

Parents:

80d9d83

Message:

First attempt to implement preemptive trap handlers
and switch to userspace. Preemptive traps are needed
for at least page faults, as page fault handling code
can trigger window underflow/overflow exceptions.

This commit also introduces userspace window buffer
for saving userspace register windows (just as in
sparc64).

These changes are unfinished and far from working
correctly.

File:

• kernel/arch/sparc32/src/userspace.c (modified) (2 diffs)

kernel/arch/sparc32/src/userspace.c

@@ -36 +36 @@
 #include <typedefs.h>
 #include <arch.h>
+#include <arch/asm.h>
 #include <abi/proc/uarg.h>
 #include <mm/as.h>
@@ -41 +42 @@
 void userspace(uspace_arg_t *kernel_uarg)
 {
+        printf("userspace(): entry=%p, stack=%p, stacksize=%d\n", kernel_uarg->uspace_entry, kernel_uarg->uspace_stack, kernel_uarg->uspace_stack_size);
         /* On real hardware this switches the CPU to user
            space mode and jumps to kernel_uarg->uspace_entry. */
-        
+
+        uint32_t psr = psr_read();
+
+        psr &= ~(1 << 7);
+        psr &= ~(1 << 6);
+
+        asm volatile (
+                "mov %[stack], %%sp\n"
+                "mov %[psr], %%psr\n"
+                "nop\n"
+                "jmp %[entry]\n"
+                "nop\n" :: [entry] "r" (kernel_uarg->uspace_entry),
+                           [psr] "r" (psr),
+                           [stack] "r" (kernel_uarg->uspace_stack + kernel_uarg->uspace_stack_size));
+
         while (true);
 }