From bd0616e6e76d5b56414a6c77131a9bb63cf5e985 Mon Sep 17 00:00:00 2001
From: Aleksa Vuckovic <aleksa@vuckovic.cc>
Date: Mon, 6 Mar 2023 01:59:33 +0100
Subject: parsing pcie MCFG table

---
 kernel/src/devices/pci.c | 40 ++++++++++++++++++++++++++++++++++++++++
 kernel/src/main.c        |  2 ++
 2 files changed, 42 insertions(+)
 create mode 100644 kernel/src/devices/pci.c

(limited to 'kernel/src')

diff --git a/kernel/src/devices/pci.c b/kernel/src/devices/pci.c
new file mode 100644
index 0000000..85c7b69
--- /dev/null
+++ b/kernel/src/devices/pci.c
@@ -0,0 +1,40 @@
+#include <types.h>
+#include <rsdp.h>
+#include <libk/stdio.h>
+#include <mcfg.h>
+#include <heap.h>
+#include <paging.h>
+#include <libk/string.h>
+
+void read_mcfgt()
+{
+	uint64_t *mcfgt_addr = find_sys_table_addr("MCFG");
+	uint64_t mcfgt_cfg_addr;
+	size_t len;
+	size_t i;
+
+	if (mcfgt_addr == NULL) {
+		printf("MCFG not found\n");
+		return;
+	}
+
+	mcfgt_cfg_addr = (uint64_t)((uint8_t *)mcfgt_addr + sizeof(MCFGT));
+	map_addr((uint64_t)mcfgt_addr, (uint64_t)mcfgt_addr, sizeof(MCFGT));
+	MCFGT *mcfgt = (MCFGT *)kalloc(sizeof(MCFGT));
+	memcpy(mcfgt, mcfgt_addr, sizeof(MCFGT));
+	len = (mcfgt->length - sizeof(MCFGT)) / 16;
+	kfree(mcfgt);
+
+	config_space_mcfgt *cfg_space =
+		(config_space_mcfgt *)kalloc(sizeof(config_space_mcfgt));
+	for (i = 0; i < len; i++) {
+		map_addr(mcfgt_cfg_addr, mcfgt_cfg_addr,
+			 sizeof(config_space_mcfgt));
+		memcpy(cfg_space, (uint64_t *)mcfgt_cfg_addr,
+		       sizeof(config_space_mcfgt));
+		printf("addr: 0x%x, group: %d, start: %d, stop: %d\n",
+		       cfg_space->base_addr, cfg_space->pci_seg_group,
+		       cfg_space->start_pci_bus, cfg_space->end_pci_bus);
+	}
+	kfree(cfg_space);
+}
diff --git a/kernel/src/main.c b/kernel/src/main.c
index f9d1b8f..2e142ca 100644
--- a/kernel/src/main.c
+++ b/kernel/src/main.c
@@ -25,6 +25,7 @@
 #include <pmm.h>
 #include <scheduler.h>
 #include <process.h>
+#include <mcfg.h>
 
 int kernel_main(mb2_tag_header *multiboot_bootinfo, uint32_t multiboot_magic);
 int kernel_main(mb2_tag_header *multiboot_bootinfo, uint32_t multiboot_magic)
@@ -52,6 +53,7 @@ int kernel_main(mb2_tag_header *multiboot_bootinfo, uint32_t multiboot_magic)
 	apic_remap_interrupts();
 	enable_interrupts();
 	init_userspace();
+	read_mcfgt();
 
 	init_scheduler();
 
-- 
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