created /kernel/isr subdir, moved isr.asm from boot to isr module, added interrupts.cc for isr() main function and isr_bootstrap() routine

git-svn-id: svn://anubis/hos/trunk@66 5b3e749e-e535-0410-8002-a9bb6afbdfca

kernel/isr/Makefile

@@ -0,0 +1,2 @@
+
+include $(HOS_TOPLEVEL)/subdir.mak

kernel/isr/interrupts.cc

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+
+#include "hos_types.h"
+#include "interrupts.h"
+
+extern "C" {
+
+void isr(u8_t int_num, int_stack_t * int_stack)
+{
+    switch (int_num)
+    {
+    }
+}
+
+} /* extern "C" */
+
+void interrupts_bootstrap()
+{
+    /* TODO: set up IDTR, IDT */
+}

kernel/isr/interrupts.h

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+
+#ifndef INTERRUPTS_H
+#define INTERRUPTS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void isr(u8_t int_num, int_stack_t * int_stack);
+
+#ifdef __cplusplus
+}
+#endif
+
+void interrupts_bootstrap();
+
+#endif

kernel/isr/isr.asm

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+
+; C ISR routine
+[extern isr]
+
+
+; Macro for creating a single ISR label
+; We need to push a junk value on the stack first
+; if the interrupt number is not 8 or 10-14.
+; This is to properly align the stack for both exceptions
+; having and not having error codes.
+%macro isr_label 1
+[global isr_%1]
+isr_%1:
+    %if ( (%1 != 8) && (%1 < 10 || %1 > 14) )
+        push    eax                 ; junk value to take error code stack space
+    %endif
+    pusha                           ; eax, ecx, edx, ebx, esp, ebp, esi, edi
+    mov     al, %1                  ; save interrupt number in al
+    %if ($ - isr_common) < 127      ; do a short jump and save 3 bytes if we can
+        jmp short isr_common
+    %else
+        jmp     isr_common
+    %endif
+%endmacro
+
+
+; The common ISR routine
+isr_common:
+    push    ds
+    push    es
+    push    fs
+    push    gs
+
+    push    esp                     ; pointer to interrupt stack
+    push    eax                     ; interrupt number
+; TODO: uncomment when isr() is defined so the build won't break
+;    call    isr
+    pop     eax                     ; restore stack pointer (this is shorter
+    pop     eax                     ; than "add esp, 8" and "lea esp, [esp+8]")
+
+    pop     gs
+    pop     fs
+    pop     es
+    pop     ds
+    popa                            ; edi, esi, ebp, <null>, ebx, edx, ecx, eax
+    lea     esp, [esp+4]            ; bypass error code
+
+    iret
+
+
+; Loop to create all of our ISR entry points
+%assign i 0
+%rep 50
+    isr_label i
+    %assign i i+1
+%endrep
+