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-rw-r--r--arch/x86/lib/bios.c347
1 files changed, 347 insertions, 0 deletions
diff --git a/arch/x86/lib/bios.c b/arch/x86/lib/bios.c
new file mode 100644
index 0000000000..298fca632c
--- /dev/null
+++ b/arch/x86/lib/bios.c
@@ -0,0 +1,347 @@
+/*
+ * From Coreboot file device/oprom/realmode/x86.c
+ *
+ * Copyright (C) 2007 Advanced Micro Devices, Inc.
+ * Copyright (C) 2009-2010 coresystems GmbH
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#include <common.h>
+#include <bios_emul.h>
+#include <vbe.h>
+#include <asm/cache.h>
+#include <asm/processor.h>
+#include <asm/i8259.h>
+#include <asm/io.h>
+#include <asm/post.h>
+#include "bios.h"
+
+/* Interrupt handlers for each interrupt the ROM can call */
+static int (*int_handler[256])(void);
+
+/* to have a common register file for interrupt handlers */
+X86EMU_sysEnv _X86EMU_env;
+
+asmlinkage void (*realmode_call)(u32 addr, u32 eax, u32 ebx, u32 ecx, u32 edx,
+ u32 esi, u32 edi);
+
+asmlinkage void (*realmode_interrupt)(u32 intno, u32 eax, u32 ebx, u32 ecx,
+ u32 edx, u32 esi, u32 edi);
+
+static void setup_realmode_code(void)
+{
+ memcpy((void *)REALMODE_BASE, &asm_realmode_code,
+ asm_realmode_code_size);
+
+ /* Ensure the global pointers are relocated properly. */
+ realmode_call = PTR_TO_REAL_MODE(asm_realmode_call);
+ realmode_interrupt = PTR_TO_REAL_MODE(__realmode_interrupt);
+
+ debug("Real mode stub @%x: %d bytes\n", REALMODE_BASE,
+ asm_realmode_code_size);
+}
+
+static void setup_rombios(void)
+{
+ const char date[] = "06/11/99";
+ memcpy((void *)0xffff5, &date, 8);
+
+ const char ident[] = "PCI_ISA";
+ memcpy((void *)0xfffd9, &ident, 7);
+
+ /* system model: IBM-AT */
+ writeb(0xfc, 0xffffe);
+}
+
+static int int_exception_handler(void)
+{
+ /* compatibility shim */
+ struct eregs reg_info = {
+ .eax = M.x86.R_EAX,
+ .ecx = M.x86.R_ECX,
+ .edx = M.x86.R_EDX,
+ .ebx = M.x86.R_EBX,
+ .esp = M.x86.R_ESP,
+ .ebp = M.x86.R_EBP,
+ .esi = M.x86.R_ESI,
+ .edi = M.x86.R_EDI,
+ .vector = M.x86.intno,
+ .error_code = 0,
+ .eip = M.x86.R_EIP,
+ .cs = M.x86.R_CS,
+ .eflags = M.x86.R_EFLG
+ };
+ struct eregs *regs = &reg_info;
+
+ debug("Oops, exception %d while executing option rom\n", regs->vector);
+ cpu_hlt();
+
+ return 0;
+}
+
+static int int_unknown_handler(void)
+{
+ debug("Unsupported software interrupt #0x%x eax 0x%x\n",
+ M.x86.intno, M.x86.R_EAX);
+
+ return -1;
+}
+
+/* setup interrupt handlers for mainboard */
+void bios_set_interrupt_handler(int intnum, int (*int_func)(void))
+{
+ int_handler[intnum] = int_func;
+}
+
+static void setup_interrupt_handlers(void)
+{
+ int i;
+
+ /*
+ * The first 16 int_handler functions are not BIOS services,
+ * but the CPU-generated exceptions ("hardware interrupts")
+ */
+ for (i = 0; i < 0x10; i++)
+ int_handler[i] = &int_exception_handler;
+
+ /* Mark all other int_handler calls as unknown first */
+ for (i = 0x10; i < 0x100; i++) {
+ /* Skip if bios_set_interrupt_handler() isn't called first */
+ if (int_handler[i])
+ continue;
+
+ /*
+ * Now set the default functions that are actually needed
+ * to initialize the option roms. The board may override
+ * these with bios_set_interrupt_handler()
+ */
+ switch (i) {
+ case 0x10:
+ int_handler[0x10] = &int10_handler;
+ break;
+ case 0x12:
+ int_handler[0x12] = &int12_handler;
+ break;
+ case 0x16:
+ int_handler[0x16] = &int16_handler;
+ break;
+ case 0x1a:
+ int_handler[0x1a] = &int1a_handler;
+ break;
+ default:
+ int_handler[i] = &int_unknown_handler;
+ break;
+ }
+ }
+}
+
+static void write_idt_stub(void *target, u8 intnum)
+{
+ unsigned char *codeptr;
+
+ codeptr = (unsigned char *)target;
+ memcpy(codeptr, &__idt_handler, __idt_handler_size);
+ codeptr[3] = intnum; /* modify int# in the code stub. */
+}
+
+static void setup_realmode_idt(void)
+{
+ struct realmode_idt *idts = NULL;
+ int i;
+
+ /*
+ * Copy IDT stub code for each interrupt. This might seem wasteful
+ * but it is really simple
+ */
+ for (i = 0; i < 256; i++) {
+ idts[i].cs = 0;
+ idts[i].offset = 0x1000 + (i * __idt_handler_size);
+ write_idt_stub((void *)((u32)idts[i].offset), i);
+ }
+
+ /*
+ * Many option ROMs use the hard coded interrupt entry points in the
+ * system bios. So install them at the known locations.
+ */
+
+ /* int42 is the relocated int10 */
+ write_idt_stub((void *)0xff065, 0x42);
+ /* BIOS Int 11 Handler F000:F84D */
+ write_idt_stub((void *)0xff84d, 0x11);
+ /* BIOS Int 12 Handler F000:F841 */
+ write_idt_stub((void *)0xff841, 0x12);
+ /* BIOS Int 13 Handler F000:EC59 */
+ write_idt_stub((void *)0xfec59, 0x13);
+ /* BIOS Int 14 Handler F000:E739 */
+ write_idt_stub((void *)0xfe739, 0x14);
+ /* BIOS Int 15 Handler F000:F859 */
+ write_idt_stub((void *)0xff859, 0x15);
+ /* BIOS Int 16 Handler F000:E82E */
+ write_idt_stub((void *)0xfe82e, 0x16);
+ /* BIOS Int 17 Handler F000:EFD2 */
+ write_idt_stub((void *)0xfefd2, 0x17);
+ /* ROM BIOS Int 1A Handler F000:FE6E */
+ write_idt_stub((void *)0xffe6e, 0x1a);
+}
+
+static u8 vbe_get_mode_info(struct vbe_mode_info *mi)
+{
+ u16 buffer_seg;
+ u16 buffer_adr;
+ char *buffer;
+
+ debug("VBE: Getting information about VESA mode %04x\n",
+ mi->video_mode);
+ buffer = PTR_TO_REAL_MODE(asm_realmode_buffer);
+ buffer_seg = (((unsigned long)buffer) >> 4) & 0xff00;
+ buffer_adr = ((unsigned long)buffer) & 0xffff;
+
+ realmode_interrupt(0x10, VESA_GET_MODE_INFO, 0x0000, mi->video_mode,
+ 0x0000, buffer_seg, buffer_adr);
+ memcpy(mi->mode_info_block, buffer, sizeof(struct vbe_mode_info));
+ mi->valid = true;
+
+ return 0;
+}
+
+static u8 vbe_set_mode(struct vbe_mode_info *mi)
+{
+ debug("VBE: Setting VESA mode %#04x\n", mi->video_mode);
+ /* request linear framebuffer mode */
+ mi->video_mode |= (1 << 14);
+ /* request clearing of framebuffer */
+ mi->video_mode &= ~(1 << 15);
+ realmode_interrupt(0x10, VESA_SET_MODE, mi->video_mode,
+ 0x0000, 0x0000, 0x0000, 0x0000);
+
+ return 0;
+}
+
+static void vbe_set_graphics(int vesa_mode, struct vbe_mode_info *mode_info)
+{
+ unsigned char *framebuffer;
+
+ mode_info->video_mode = (1 << 14) | vesa_mode;
+ vbe_get_mode_info(mode_info);
+
+ framebuffer = (unsigned char *)mode_info->vesa.phys_base_ptr;
+ debug("VBE: resolution: %dx%d@%d\n",
+ le16_to_cpu(mode_info->vesa.x_resolution),
+ le16_to_cpu(mode_info->vesa.y_resolution),
+ mode_info->vesa.bits_per_pixel);
+ debug("VBE: framebuffer: %p\n", framebuffer);
+ if (!framebuffer) {
+ debug("VBE: Mode does not support linear framebuffer\n");
+ return;
+ }
+
+ vbe_set_mode(mode_info);
+}
+
+void bios_run_on_x86(pci_dev_t pcidev, unsigned long addr, int vesa_mode,
+ struct vbe_mode_info *mode_info)
+{
+ u32 num_dev;
+
+ num_dev = PCI_BUS(pcidev) << 8 | PCI_DEV(pcidev) << 3 |
+ PCI_FUNC(pcidev);
+
+ /* Needed to avoid exceptions in some ROMs */
+ interrupt_init();
+
+ /* Set up some legacy information in the F segment */
+ setup_rombios();
+
+ /* Set up C interrupt handlers */
+ setup_interrupt_handlers();
+
+ /* Set up real-mode IDT */
+ setup_realmode_idt();
+
+ /* Make sure the code is placed. */
+ setup_realmode_code();
+
+ disable_caches();
+ debug("Calling Option ROM at %lx, pci device %#x...", addr, num_dev);
+
+ /* Option ROM entry point is at OPROM start + 3 */
+ realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0,
+ 0x0);
+ debug("done\n");
+
+ if (vesa_mode != -1)
+ vbe_set_graphics(vesa_mode, mode_info);
+}
+
+asmlinkage int interrupt_handler(u32 intnumber, u32 gsfs, u32 dses,
+ u32 edi, u32 esi, u32 ebp, u32 esp,
+ u32 ebx, u32 edx, u32 ecx, u32 eax,
+ u32 cs_ip, u16 stackflags)
+{
+ u32 ip;
+ u32 cs;
+ u32 flags;
+ int ret = 0;
+
+ ip = cs_ip & 0xffff;
+ cs = cs_ip >> 16;
+ flags = stackflags;
+
+#ifdef CONFIG_REALMODE_DEBUG
+ debug("oprom: INT# 0x%x\n", intnumber);
+ debug("oprom: eax: %08x ebx: %08x ecx: %08x edx: %08x\n",
+ eax, ebx, ecx, edx);
+ debug("oprom: ebp: %08x esp: %08x edi: %08x esi: %08x\n",
+ ebp, esp, edi, esi);
+ debug("oprom: ip: %04x cs: %04x flags: %08x\n",
+ ip, cs, flags);
+ debug("oprom: stackflags = %04x\n", stackflags);
+#endif
+
+ /*
+ * Fetch arguments from the stack and put them to a place
+ * suitable for the interrupt handlers
+ */
+ M.x86.R_EAX = eax;
+ M.x86.R_ECX = ecx;
+ M.x86.R_EDX = edx;
+ M.x86.R_EBX = ebx;
+ M.x86.R_ESP = esp;
+ M.x86.R_EBP = ebp;
+ M.x86.R_ESI = esi;
+ M.x86.R_EDI = edi;
+ M.x86.intno = intnumber;
+ M.x86.R_EIP = ip;
+ M.x86.R_CS = cs;
+ M.x86.R_EFLG = flags;
+
+ /* Call the interrupt handler for this interrupt number */
+ ret = int_handler[intnumber]();
+
+ /*
+ * This code is quite strange...
+ *
+ * Put registers back on the stack. The assembler code will pop them
+ * later. We force (volatile!) changing the values of the parameters
+ * of this function. We know that they stay alive on the stack after
+ * we leave this function.
+ */
+ *(volatile u32 *)&eax = M.x86.R_EAX;
+ *(volatile u32 *)&ecx = M.x86.R_ECX;
+ *(volatile u32 *)&edx = M.x86.R_EDX;
+ *(volatile u32 *)&ebx = M.x86.R_EBX;
+ *(volatile u32 *)&esi = M.x86.R_ESI;
+ *(volatile u32 *)&edi = M.x86.R_EDI;
+ flags = M.x86.R_EFLG;
+
+ /* Pass success or error back to our caller via the CARRY flag */
+ if (ret) {
+ flags &= ~1; /* no error: clear carry */
+ } else {
+ debug("int%02x call returned error\n", intnumber);
+ flags |= 1; /* error: set carry */
+ }
+ *(volatile u16 *)&stackflags = flags;
+
+ return ret;
+}
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