X-Git-Url: http://git.joshuawise.com/netwatch.git/blobdiff_plain/9b8c947be2d07e7c5006a92127e58b6022718cbd..6b988ea9bdbc4f1e78bbde0652036c083dbc4aa1:/grubload/multiboot_c.c

diff --git a/grubload/multiboot_c.c b/grubload/multiboot_c.c
index c87b675..890a003 100644
--- a/grubload/multiboot_c.c
+++ b/grubload/multiboot_c.c
@@ -1,4 +1,11 @@
 #include "console.h"
+#include <io.h>
+#include <smram.h>
+
+#define INFO_SIGNATURE 0x5754454E
+
+extern char _binary_realmode_bin_start[];
+extern int _binary_realmode_bin_size;
 
 struct mb_info
 {
@@ -18,29 +25,87 @@ struct mod_info
 	void *reserved;
 };
 
-void c_start(unsigned int magic, struct mb_info *wee)
+struct info_section
+{
+	unsigned int signature;
+	void (*firstrun)();
+};
+
+void panic(const char *msg)
+{
+	puts("PANIC: ");
+	puts(msg);
+	puts("\nSystem halted\n");
+	while(1) asm("hlt");
+}
+
+void c_start(unsigned int magic, struct mb_info *mbinfo)
 {
-	unsigned short *grubptr = 0x7CFE;
+	struct mod_info *mods = mbinfo->mods;
+	unsigned short *grubptr = (unsigned short *)0x7CFE;
+	unsigned char smramc;
 	int i;
 	
-	puts("Magic is: ");
-	puthex(magic);
-	puts("\nMultiboot header is: ");
-	puthex(wee);
-	puts("\n");
+	void (*realmode)() = (void (*)()) 0x4000;
+	
 	show_cursor();
+	puts("NetWatch loader\n");
 	
-	puts("Grubptr is: ");
-	puthex(*grubptr);
-	puts("\n");
+	if (magic != 0x2BADB002)
+		panic("Bootloader was not multiboot compliant; cannot continue.");
+	
+	for (i = 0; i < mbinfo->mod_cnt; i++)
+	{
+		puts("Module found:\n");
+		puts("  Start: "); puthex(mods[i].mod_start); puts("\n");
+		puts("  Size: "); puthex(mods[i].mod_end - mods[i].mod_start); puts("\n");
+		puts("  Name: "); puts(mods[i].mod_string); puts("\n");
+	}
+
+	if (mbinfo->mod_cnt != 1)
+		panic("Expected exactly one module; cannot continue.");
+
+	puts("Current USB state is: "); puthex(pci_read16(0, 31, 2, 0xC0)); puts(" "); puthex(pci_read16(0, 31, 4, 0xC0)); puts("\n");
+	puts("Current SMI state is: "); puthex(inl(0x830)); puts("\n");
+	puts("Current SMRAMC state is: "); puthex(pci_read8(0, 0, 0, 0x70)); puts("\n");
 	
-	for (i = 0; i < wee->mod_cnt; i++)
+	outl(0x830, inl(0x830) & ~0x1);	/* turn off SMIs */
+	
+	/* Try really hard to shut up USB_LEGKEY. */
+	pci_write16(0, 31, 2, 0xC0, pci_read16(0, 31, 2, 0xC0));
+	pci_write16(0, 31, 2, 0xC0, 0);
+	pci_write16(0, 31, 4, 0xC0, pci_read16(0, 31, 4, 0xC0));
+	pci_write16(0, 31, 4, 0xC0, 0);
+
+
+	/* Open the SMRAM aperture and load our ELF. */
+	smram_state_t old_smramc = smram_save_state();
+
+	if (smram_aseg_set_state(SMRAM_ASEG_OPEN) != 0)
+		panic("Opening SMRAM failed; cannot load ELF.");
+
+	load_elf(mods[0].mod_start, mods[0].mod_end - mods[0].mod_start);
+
+	struct info_section * info = (struct info_section *)0x10000;
+	if (info->signature != INFO_SIGNATURE)
 	{
-		puts("Module:\n");
-		puts("  Start: "); puthex(wee->mods[i].mod_start); puts("\n");
-		puts("  Size: "); puthex(wee->mods[i].mod_end - wee->mods[i].mod_start); puts("\n");
-		puts("  Name: "); puts(wee->mods[i].mod_string); puts("\n");
+		smram_restore_state(old_smramc);		/* Restore so that video ram is touchable again. */
+		panic("Info section signature mismatch.");
 	}
-	while (1)
-		;
+
+	info->firstrun();
+	smram_restore_state(old_smramc);
+
+	puts("Waiting for a bit before returning to real mode...");
+	for (i=0; i<0x500000; i++)
+	{
+		if ((i % 0x100000) == 0)
+			puts(".");
+		inb(0x80);
+	}
+	puts("\n");
+
+	puts("Now returning to real mode.\n");	
+	memcpy(0x4000, _binary_realmode_bin_start, (int)&_binary_realmode_bin_size);
+	realmode();	// goodbye!
 }