avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/x86/lib/bios.c

@@ -0,0 +1,351 @@
+/*
+ * 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 <linux/linkage.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)
+{
+	int video_mode = mi->video_mode;
+
+	debug("VBE: Setting VESA mode %#04x\n", video_mode);
+	/* request linear framebuffer mode */
+	video_mode |= (1 << 14);
+	/* don't clear the framebuffer, we do that later */
+	video_mode |= (1 << 15);
+	realmode_interrupt(0x10, VESA_SET_MODE, 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;
+	}
+
+	mode_info->video_mode &= 0x3ff;
+	vbe_set_mode(mode_info);
+}
+
+void bios_run_on_x86(struct udevice *dev, unsigned long addr, int vesa_mode,
+		     struct vbe_mode_info *mode_info)
+{
+	pci_dev_t pcidev = dm_pci_get_bdf(dev);
+	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();
+
+	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;
+}