From c2d88b639c759e06444c1bf0efdd96e243d3a6c2 Mon Sep 17 00:00:00 2001
From: Marvin Borner
Date: Sun, 6 Sep 2020 13:15:14 +0200
Subject: Started ACPI driver
---
kernel/drivers/acpi.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
create mode 100644 kernel/drivers/acpi.c
(limited to 'kernel/drivers')
diff --git a/kernel/drivers/acpi.c b/kernel/drivers/acpi.c
new file mode 100644
index 0000000..02f3718
--- /dev/null
+++ b/kernel/drivers/acpi.c
@@ -0,0 +1,54 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+
+#include <acpi.h>
+#include <assert.h>
+#include <cpu.h>
+#include <def.h>
+#include <mem.h>
+#include <print.h>
+
+int check_sdt(struct sdt_header *header)
+{
+ u8 sum = 0;
+
+ for (u32 i = 0; i < header->length; i++)
+ sum += ((char *)header)[i];
+
+ return sum == 0;
+}
+
+int check_sdp(struct sdp_header *header)
+{
+ u8 sum = 0;
+
+ for (u32 i = 0; i < sizeof(struct rsdp); i++)
+ sum += ((char *)header)[i];
+
+ return sum == 0;
+}
+
+struct rsdp *find_rsdp()
+{
+ // Main BIOS area
+ for (int i = 0xe0000; i < 0xfffff; i++) {
+ if (memcmp((u32 *)i, RSDP_MAGIC, 8) == 0)
+ return (struct rsdp *)i;
+ }
+
+ // Or first KB of EBDA?
+ for (int i = 0x100000; i < 0x101000; i++) {
+ if (memcmp((u32 *)i, RSDP_MAGIC, 8) == 0)
+ return (struct rsdp *)i;
+ }
+
+ return NULL;
+}
+
+void acpi_install()
+{
+ struct rsdp *rsdp = find_rsdp();
+ assert(rsdp && rsdp->header.revision == 0 && check_sdp(&rsdp->header));
+ struct rsdt *rsdt = rsdp->rsdt;
+ assert(rsdt && memcmp(rsdt->header.signature, RSDT_MAGIC, 4) == 0 &&
+ check_sdt(&rsdt->header));
+}
--
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