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authorRobin Krahl <robin.krahl@ireas.org>2017-03-06 02:52:05 +0100
committerRobin Krahl <robin.krahl@ireas.org>2017-03-06 02:52:05 +0100
commit05b9ca73793047e795e46a2ae13db02c34b8a7c3 (patch)
tree5ab672db87c57cbe01662547e7733e71aa748743 /core
parent28301499381cb541eec4eb99f61e3d1a193c5a2d (diff)
downloadgarmos-05b9ca73793047e795e46a2ae13db02c34b8a7c3.tar.gz
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idt: add interruption handling
The Interruption Descriptor Table (IDT) is implemented in idt.{c,h} as part of the core, but the setup and activation of the IDT and the registration of specific interruption request handlers is part of arch.{c,h}. The request handlers are implemented in idt.s and delegate to kernel_handle_interrupt.
Diffstat (limited to 'core')
-rw-r--r--core/idt.c76
-rw-r--r--core/kernel.c15
2 files changed, 88 insertions, 3 deletions
diff --git a/core/idt.c b/core/idt.c
new file mode 100644
index 0000000..a20eb69
--- /dev/null
+++ b/core/idt.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2017 Robin Krahl <robin.krahl@ireas.org>
+ *
+ * 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 3 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.
+ */
+
+#include <garmos/arch.h>
+#include <garmos/gdt.h>
+#include <garmos/idt.h>
+#include <garmos/kernel.h>
+#include <garmos/types.h>
+
+#define IDT_GATE_COUNT 256
+
+struct idt_gate {
+ uint16_t handler_lo;
+ uint16_t gdt_offset;
+ uint8_t reserved;
+ uint8_t access;
+ uint16_t handler_hi;
+} __attribute__((packed));
+
+struct idt_gate idt[IDT_GATE_COUNT];
+
+struct idtp idtp = {
+ .limit = IDT_GATE_COUNT * sizeof(*idt) - 1,
+ .pointer = idt,
+};
+
+static void idt_set(uint8_t no, uint16_t offset, uint32_t handler,
+ uint8_t access, uint8_t flags);
+
+void idt_init(void)
+{
+ uint32_t offset = gdt_get_code_offset();
+ uint32_t i;
+ uint8_t *no = irqnos;
+ uint32_t *addr = irqhdls;
+
+ ker_dbg("Initializing IDT ...");
+
+ for (i = 0; i < IDT_GATE_COUNT; i++)
+ idt_set(i, offset, (uint32_t) &irqign, 0, 0xE);
+
+ for (; *no; no++, addr++) {
+ if (!*addr)
+ continue;
+ ker_dbg("Registerung IRQ handler ...");
+ idt_set(*no, offset, *addr, 0, 0xE);
+ }
+
+ idtset(idtp);
+}
+
+void idt_activate(void)
+{
+ idtact();
+}
+
+static void idt_set(uint8_t no, uint16_t offset, uint32_t handler,
+ uint8_t access, uint8_t flags)
+{
+ idt[no].handler_lo = handler & 0xFFFF;
+ idt[no].handler_hi = (handler >> 16) & 0xFFFF;
+ idt[no].gdt_offset = offset;
+ idt[no].reserved = 0;
+ idt[no].access = 0x80 | flags | ((access & 0x3) << 5);
+}
diff --git a/core/kernel.c b/core/kernel.c
index c159aef..098db12 100644
--- a/core/kernel.c
+++ b/core/kernel.c
@@ -12,24 +12,33 @@
* more details.
*/
+#include <garmos/idt.h>
#include <garmos/gdt.h>
#include <garmos/kernel.h>
#include <garmos/term.h>
#include <garmos/types.h>
-
void ker_dbg(char *s)
{
term_print(s);
term_print("\n");
}
+uint32_t kernel_handle_interrupt(uint8_t no, uint32_t esp)
+{
+ return esp;
+}
+
void kernel_main(uint32_t multiboot, unsigned int *magicno)
{
+ term_clear();
+
gdt_init();
+ idt_init();
+
+ idt_activate();
- term_clear();
term_print("garmos 0.1.0\n\n");
- while(1);
+ while (1);
}