X-Git-Url: http://git.joshuawise.com/netwatch.git/blobdiff_plain/81148fa15713ee68be49610206526d0725a5868f..4509619557e06ff851f93ddf1eaca7a898d46b2f:/grubload/multiboot_c.c?ds=inline 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 +#include + +#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++) {