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Diffstat (limited to 'sos-code-article6.5/hwcore/irq_wrappers.S')
| -rw-r--r-- | sos-code-article6.5/hwcore/irq_wrappers.S | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/sos-code-article6.5/hwcore/irq_wrappers.S b/sos-code-article6.5/hwcore/irq_wrappers.S new file mode 100644 index 0000000..8945123 --- /dev/null +++ b/sos-code-article6.5/hwcore/irq_wrappers.S @@ -0,0 +1,220 @@ +/* Copyright (C) 2004 The KOS Team + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either version 2 + of the License, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, + USA. +*/ + +.file "irq_wrappers.S" + +.text + +/** The address of the table of handlers (defined in irq.c) */ +.extern sos_irq_handler_array + +/** The address of the table of wrappers (defined below, and shared + with irq.c */ +.globl sos_irq_wrapper_array + +/** The variable holding the nested level of the IRQ handlers */ +.extern sos_irq_nested_level_counter + +/* These pre-handlers are for IRQ (Master PIC) */ +.irp id, 0,1,2,3,4,5,6,7 + + .p2align 2, 0x90 + + sos_irq_wrapper_\id: + .type sos_irq_wrapper_\id,@function + + /* + * Backup the CPU context + */ + + /* Fake error code */ + pushl $0 + + /* Backup the actual context */ + pushl %ebp + movl %esp, %ebp + + pushl %edi + pushl %esi + pushl %edx + pushl %ecx + pushl %ebx + pushl %eax + subl $2,%esp + pushw %ss + pushw %ds + pushw %es + pushw %fs + pushw %gs + + /* + * Increment IRQ nested level + */ + incl sos_irq_nested_level_counter + + /* Send EOI to PIC. See Intel 8259 datasheet + available on Kos website */ + movb $0x20, %al + outb %al, $0x20 + + /* + * Call the handler with IRQ number as argument + */ + pushl $\id + leal sos_irq_handler_array,%edi + call *\id*4(%edi) + addl $4, %esp + + /* + * Decrement IRQ nested level + */ + cli /* Just in case we messed up everything in the handler */ + subl $1, sos_irq_nested_level_counter + + /* sos_irq_nested_level_counter went below 0 ?! */ + jnc 2f + + 1: /* Yes: Print fatal error message */ + pushl $msg_nested_level_overflow + call sos_display_fatal_error + addl $4, %esp ; jmp 1b + /* Never returns */ + + 2: /* No: all right ! */ + + /* Restore the context */ + popw %gs + popw %fs + popw %es + popw %ds + popw %ss + addl $2,%esp + popl %eax + popl %ebx + popl %ecx + popl %edx + popl %esi + popl %edi + popl %ebp + + /* Remove fake error code */ + addl $4, %esp + + iret + .endr + + +/* These pre-handlers are for IRQ (Slave PIC) */ +.irp id, 8,9,10,11,12,13,14,15 + + .p2align 2, 0x90 + + sos_irq_wrapper_\id: + .type sos_irq_wrapper_\id,@function + + /* + * Backup the CPU context + */ + + /* Fake error code */ + pushl $0 + + /* Backup the actual context */ + pushl %ebp + movl %esp, %ebp + + pushl %edi + pushl %esi + pushl %edx + pushl %ecx + pushl %ebx + pushl %eax + subl $2,%esp + pushw %ss + pushw %ds + pushw %es + pushw %fs + pushw %gs + + /* + * Increment IRQ nested level + */ + incl sos_irq_nested_level_counter + + /* Send EOI to PIC. See Intel 8259 datasheet + available on Kos website */ + movb $0x20, %al + outb %al, $0xa0 + outb %al, $0x20 + + /* + * Call the handler with IRQ number as argument + */ + pushl $\id + leal sos_irq_handler_array,%edi + call *\id*4(%edi) + addl $4, %esp + + /* + * Decrement IRQ nested level + */ + cli /* Just in case we messed up everything in the handler */ + subl $1, sos_irq_nested_level_counter + + /* sos_irq_nested_level_counter went below 0 ?! */ + jnc 2f + + 1: /* Yes: Print fatal error message */ + pushl $msg_nested_level_overflow + call sos_display_fatal_error + addl $4, %esp ; jmp 1b + /* Never returns */ + + 2: /* No: all right ! */ + + /* Restore the context */ + popw %gs + popw %fs + popw %es + popw %ds + popw %ss + addl $2,%esp + popl %eax + popl %ebx + popl %ecx + popl %edx + popl %esi + popl %edi + popl %ebp + + /* Remove fake error code */ + addl $4, %esp + + iret + .endr + +.section ".rodata" +msg_nested_level_overflow: + .string "irq_wrappers.S: IRQ Nested level overflow ! System halted." + +/* Build the sos_irq_wrapper_array, shared with irq.c */ +.p2align 5, 0x0 +sos_irq_wrapper_array: + .irp id, 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .long (sos_irq_wrapper_\id) + .endr |