diff options
Diffstat (limited to 'main.c')
-rw-r--r-- | main.c | 49 |
1 files changed, 49 insertions, 0 deletions
@@ -0,0 +1,49 @@ +#include "bios.h" +#include "pci.h" +#include "string.h" + +#define PCI_VENDOR_ID_INTEL 0x8086 +#define PCI_DEVICE_ID_INTEL_82441 0x1237 +#define PCI_DEVICE_ID_INTEL_Q35_MCH 0x29c0 + +#define I440FX_PAM0 0x59 +#define Q35_HOST_BRIDGE_PAM0 0x90 + +static void make_bios_writable(void) +{ + const int bdf = 0; + const uint8_t *bios_start = (uint8_t *)0xffff0000; + uint8_t *low_start = (uint8_t *)0xf0000; + int pambase; + + uint32_t id = pci_config_readl(bdf, 0); + if (id == (PCI_VENDOR_ID_INTEL | (PCI_DEVICE_ID_INTEL_82441 << 16))) + pambase = I440FX_PAM0; + else if (id == (PCI_VENDOR_ID_INTEL | (PCI_DEVICE_ID_INTEL_Q35_MCH << 16))) + pambase = Q35_HOST_BRIDGE_PAM0; + else + panic(); + + // Make ram from 0xc0000-0xf0000 read-write + int i; + for (i=0; i<6; i++) { + int pam = pambase + 1 + i; + pci_config_writeb(bdf, pam, 0x33); + } + + // Make ram from 0xf0000-0x100000 read-write and shadow BIOS + // We're still running from 0xffff0000 + pci_config_writeb(bdf, pambase, 0x30); + memcpy(low_start, bios_start, 0x10000); +} + + +int main(void) +{ + make_bios_writable(); + // extract_acpi(); + // extract_smbios(); + // extract_kernel(); + // boot_linux(); + panic(); +} |