X-Git-Url: http://git.joshuawise.com/netwatch.git/blobdiff_plain/81148fa15713ee68be49610206526d0725a5868f..6b988ea9bdbc4f1e78bbde0652036c083dbc4aa1:/grubload/multiboot_c.c

diff --git a/grubload/multiboot_c.c b/grubload/multiboot_c.c
index 990ffc6..890a003 100644
--- a/grubload/multiboot_c.c
+++ b/grubload/multiboot_c.c
@@ -1,5 +1,8 @@
 #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;
@@ -22,8 +25,23 @@ 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)
+{
+	struct mod_info *mods = mbinfo->mods;
 	unsigned short *grubptr = (unsigned short *)0x7CFE;
 	unsigned char smramc;
 	int i;
@@ -34,24 +52,18 @@ void c_start(unsigned int magic, struct mb_info *wee)
 	puts("NetWatch loader\n");
 	
 	if (magic != 0x2BADB002)
-	{
-		puts("Bootloader was not multiboot compliant; cannot continue.\n");
-		while(1) asm("hlt");
-	}
+		panic("Bootloader was not multiboot compliant; cannot continue.");
 	
-	for (i = 0; i < wee->mod_cnt; i++)
+	for (i = 0; i < mbinfo->mod_cnt; i++)
 	{
 		puts("Module found:\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");
+		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 (wee->mod_cnt != 1)
-	{
-		puts("Expected exactly one module; cannot continue.\n");
-		while(1) asm("hlt");
-	}
+	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");
@@ -64,12 +76,26 @@ void c_start(unsigned int magic, struct mb_info *wee)
 	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);
-	smramc = pci_read8(0, 0, 0, 0x70);
-	pci_write8(0, 0, 0, 0x70, (smramc & 0xF0) | 0x04);
-	load_elf(wee->mods[0].mod_start, wee->mods[0].mod_end - wee->mods[0].mod_start);
-	pci_write8(0, 0, 0, 0x70, smramc);
-	outb(0x830, inb(0x830) | 0x41);	/* turn on the SMIs we want */
-	
+
+
+	/* 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)
+	{
+		smram_restore_state(old_smramc);		/* Restore so that video ram is touchable again. */
+		panic("Info section signature mismatch.");
+	}
+
+	info->firstrun();
+	smram_restore_state(old_smramc);
+
 	puts("Waiting for a bit before returning to real mode...");
 	for (i=0; i<0x500000; i++)
 	{