Changeset b808660 in mainline for kernel/arch/ia32/include/asm.h

Timestamp:

2010-07-08T20:03:52Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

bee2d4c

Parents:

9097982f

Message:

Do not align ia32 int handlers on any pre-defined power-of-two boundary but
rather define each one as a separate procedure with its own global label. The
label is used to populate the IDT and it also helps to maintain consistency
between C and assembly.

The old way was very error-prone because one did not get a warning when a
handler exceeded the size limit given by the alignment, which usually resulted
in very weird crashes.

In principle, the old way was also rather wasteful as the handler had to be
aligned on a power-of-two address. With the int handler size around 160 bytes,
the bytes 160 - 255 in each handler were simply wasted. In practice, however,
the image.iso size did not change (I'd expect it to drop by around 8K).

The old way did not detect a mistmatch between the C code idea of how many IDT
entries there are and the assembly language code idea of the same thing. It was
possible to initialize an IDT entry to point to some garbage and nobody would
notice until the int occurred.

The new method was a bit tiresome to write as there was a lot of copy'n'paste.
But since it was a one-time effort, I lumped it. If you know of a way to write a
for-loop in C preprocessor or use GAS assmebler macros in a sensible way, I will
gladly use your improvement.

File:

• kernel/arch/ia32/include/asm.h (modified) (2 diffs)

kernel/arch/ia32/include/asm.h

@@ -425 +425 @@
 
 extern void paging_on(void);
-extern void interrupt_handlers(void);
 extern void enable_l_apic_in_msr(void);
 
@@ -431 +430 @@
 extern void asm_fake_loop(uint32_t);
 
+extern uintptr_t int_0;
+extern uintptr_t int_1;
+extern uintptr_t int_2;
+extern uintptr_t int_3;
+extern uintptr_t int_4;
+extern uintptr_t int_5;
+extern uintptr_t int_6;
+extern uintptr_t int_7;
+extern uintptr_t int_8;
+extern uintptr_t int_9;
+extern uintptr_t int_10;
+extern uintptr_t int_11;
+extern uintptr_t int_12;
+extern uintptr_t int_13;
+extern uintptr_t int_14;
+extern uintptr_t int_15;
+extern uintptr_t int_16;
+extern uintptr_t int_17;
+extern uintptr_t int_18;
+extern uintptr_t int_19;
+extern uintptr_t int_20;
+extern uintptr_t int_21;
+extern uintptr_t int_22;
+extern uintptr_t int_23;
+extern uintptr_t int_24;
+extern uintptr_t int_25;
+extern uintptr_t int_26;
+extern uintptr_t int_27;
+extern uintptr_t int_28;
+extern uintptr_t int_29;
+extern uintptr_t int_30;
+extern uintptr_t int_31;
+extern uintptr_t int_32;
+extern uintptr_t int_33;
+extern uintptr_t int_34;
+extern uintptr_t int_35;
+extern uintptr_t int_36;
+extern uintptr_t int_37;
+extern uintptr_t int_38;
+extern uintptr_t int_39;
+extern uintptr_t int_40;
+extern uintptr_t int_41;
+extern uintptr_t int_42;
+extern uintptr_t int_43;
+extern uintptr_t int_44;
+extern uintptr_t int_45;
+extern uintptr_t int_46;
+extern uintptr_t int_47;
+extern uintptr_t int_48;
+extern uintptr_t int_49;
+extern uintptr_t int_50;
+extern uintptr_t int_51;
+extern uintptr_t int_52;
+extern uintptr_t int_53;
+extern uintptr_t int_54;
+extern uintptr_t int_55;
+extern uintptr_t int_56;
+extern uintptr_t int_57;
+extern uintptr_t int_58;
+extern uintptr_t int_59;
+extern uintptr_t int_60;
+extern uintptr_t int_61;
+extern uintptr_t int_62;
+extern uintptr_t int_63;
+
 #endif