put the stack in bss to save space on disk

[netwatch.git] / grubload / multiboot_c.c

diff --git a/grubload/multiboot_c.c b/grubload/multiboot_c.c
index c75e830aa90fdcb9f6a6eea3659a87ce78e8c117..890a003471db280f15a6941821a9d2c04e81b265 100644 (file)
--- a/grubload/multiboot_c.c
+++ b/grubload/multiboot_c.c
@@ -2,6 +2,8 @@
 #include <io.h>
 #include <smram.h>
 
 #include <io.h>
 #include <smram.h>
 

+#define INFO_SIGNATURE 0x5754454E
+

 extern char _binary_realmode_bin_start[];
 extern int _binary_realmode_bin_size;
 
 extern char _binary_realmode_bin_start[];
 extern int _binary_realmode_bin_size;
 


@@ -23,9 +25,23 @@ struct mod_info
        void *reserved;
 };
 
        void *reserved;
 };
 

-void c_start(unsigned int magic, struct mb_info *info)
+struct info_section

 {
 {

-       struct mod_info *mods = mods;
+       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;
        unsigned short *grubptr = (unsigned short *)0x7CFE;
        unsigned char smramc;
        int i;


@@ -36,12 +52,9 @@ void c_start(unsigned int magic, struct mb_info *info)
        puts("NetWatch loader\n");
        
        if (magic != 0x2BADB002)
        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 < info->mod_cnt; i++)
+       for (i = 0; i < mbinfo->mod_cnt; i++)

        {
                puts("Module found:\n");
                puts("  Start: "); puthex(mods[i].mod_start); puts("\n");
        {
                puts("Module found:\n");
                puts("  Start: "); puthex(mods[i].mod_start); puts("\n");


@@ -49,11 +62,8 @@ void c_start(unsigned int magic, struct mb_info *info)
                puts("  Name: "); puts(mods[i].mod_string); puts("\n");
        }
 
                puts("  Name: "); puts(mods[i].mod_string); puts("\n");
        }
 

-       if (info->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");
 
        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");


@@ -72,17 +82,20 @@ void c_start(unsigned int magic, struct mb_info *info)
        smram_state_t old_smramc = smram_save_state();
 
        if (smram_aseg_set_state(SMRAM_ASEG_OPEN) != 0)
        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("Opening SMRAM failed; cannot load ELF.\n");
-       }
-       else
-       {
-               load_elf(mods[0].mod_start, mods[0].mod_end - mods[0].mod_start);
-               smram_restore_state(old_smramc);
+               smram_restore_state(old_smramc);                /* Restore so that video ram is touchable again. */
+               panic("Info section signature mismatch.");

        }
 
        }
 

-       outb(0x830, inb(0x830) | 0x41); /* turn on the SMIs we want */
-       
+       info->firstrun();
+       smram_restore_state(old_smramc);
+

        puts("Waiting for a bit before returning to real mode...");
        for (i=0; i<0x500000; i++)
        {
        puts("Waiting for a bit before returning to real mode...");
        for (i=0; i<0x500000; i++)
        {