diff options
Diffstat (limited to 'nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S')
| -rw-r--r-- | nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S b/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S index 9a1e1e64e..ded55a147 100644 --- a/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S +++ b/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S @@ -106,26 +106,43 @@ up_fullcontextrestore: cli - /* We now have everything we need from the old stack. Now get the new - * stack pointer. + /* Get the value of the stack pointer as it was when the pusha was + * executed the interrupt handler. */ movl (4*REG_SP)(%eax), %esp /* Create an interrupt stack frame for the final iret. * - * SP Before -> - * SS - * ESP - * EFLAGS - * CS - * SP After -> EIP + * + * IRET STACK + * PRIO CHANGE No PRIO CHANGE + * --------------- ----------------- + * SP Before -> + * SS EFLAGS + * ESP CS + * EFLAGS -> EIP + * CS ... + * SP After -> EIP + * + * So, first check for a priority change. */ + movl (4*REG_CS)(%eax), %edx + andl $3, %edx + mov %cs, %ebx + andl $3, %ebx + cmpb %bl, %dl + je .Lnopriochange + + /* The priority will change... put SS and ESP on the stack */ + mov (4*REG_SS)(%eax), %ebx push %ebx movl (4*REG_SP)(%eax), %ebx push %ebx + +.Lnopriochange: movl (4*REG_EFLAGS)(%eax), %ebx push %ebx mov (4*REG_CS)(%eax), %ebx @@ -162,4 +179,3 @@ up_fullcontextrestore: iret .size up_fullcontextrestore, . - up_fullcontextrestore .end - |