#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// mips/nanonote/nand-boot.ccp: standalone program for booting from nand.
// Copyright 2010 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

asm volatile ("\t.set noreorder\n"
	"\t.text\n"
	"\t.globl __start\n"
	"\t.globl addr_0\n"
	"addr_0:\n"
	"\t.word ~0\n"
	"__start:\n"
	"\tbal 1f\n"
	"__hack_label:\n"
	"\tnop\n"
	"\t.word _gp\n"
	"1:\n"
	"\tori $t0, $zero, 0x0006\n"
	"\tmtc0 $t0, $12\n"
	"\tlw $gp, 0($ra)\n"
	"\tla $sp, stack + 0x1000\n"
	"\tla $t9, nandboot_start\n"
	"\tjr $t9\n"
	"\tnop\n"
	"\t.fill 0x1b8 - (. - addr_0)\n"
	"\t.word 0xd2b9e1a8\n"	// Disk signature.
	"\t.short 0x0000\n"

	"\t.byte 0x00\n"			// bootable: no.
	"\t.byte 0x00, 0x02, 0x00\n"		// first sector chs.
	"\t.byte 0x83\n"			// type.
	"\t.byte 0x08, 0x18, 0x00\n"		// last sector chs.
	"\t.byte 0x01, 0x00, 0x00, 0x00\n"	// first sector, lba.
	"\t.byte 0xff, 0x01, 0x00, 0x00\n"	// size, lba.

	"\t.byte 0x00\n"			// bootable: no.
	"\t.byte 0x08, 0x19, 0x00\n"		// first sector chs.
	"\t.byte 0x83\n"			// type.
	"\t.byte 0x05, 0xe1, 0xf3\n"		// last sector chs.
	"\t.byte 0x00, 0x02, 0x00, 0x00\n"	// first sector, lba: 256 kB.
	"\t.byte 0x00, 0xfe, 0x1f, 0x00\n"	// size, lba: 1 GB - first.

	"\t.byte 0\n"		// bootable: no.
	"\t.byte 0, 0, 0\n"	// first sector chs.
	"\t.byte 0\n"		// type.
	"\t.byte 0, 0, 0\n"	// last sector chs.
	"\t.byte 0, 0, 0, 0\n"	// first sector, lba.
	"\t.byte 0, 0, 0, 0\n"	// size, lba.

	"\t.byte 0\n"		// bootable: no.
	"\t.byte 0, 0, 0\n"	// first sector chs.
	"\t.byte 0\n"		// type.
	"\t.byte 0, 0, 0\n"	// last sector chs.
	"\t.byte 0, 0, 0, 0\n"	// first sector, lba.
	"\t.byte 0, 0, 0, 0\n"	// size, lba.

	"\t.byte 0x55, 0xaa\n"	// mbr signature.

	"\t.set reorder")

#define __KERNEL__
#include <jz4740.hh>

#define DELAY()

static void debug (unsigned ch):
	while !(UART0_LSR & UARTLSR_TDRQ):
	UART0_TDR = ch

static void debug_num (unsigned num, unsigned base, unsigned min_digits = 1):
	char const *encode = "0123456789abcdef"
	unsigned digits = 1
	unsigned power = 1
	while power <= num / base || min_digits > digits:
		power *= base
		++digits
	for unsigned i = 0; i < digits; ++i:
		unsigned d = num / power
		debug (encode[d])
		num -= d * power
		power /= base

static void debug (char const *f, ...):
	unsigned *last = (unsigned *)&f
	while *f:
		if *f == '%':
			++f
			switch *f:
				case '%':
					debug ('%')
					break
				case 'd':
					++last
					debug_num (*last, 10)
					break
				case 'x':
					++last
					debug_num (*last, 0x10)
					break
				case 's':
					++last
					char *str = (char*)*last
					while *str:
						debug (*str++)
					break
				default:
					debug ("warning: invalid character in dbg format string\n")
					break
		else:
			debug (*f)
		++f

#define debug_line() debug ("nand-boot line %d\n", __LINE__)

#include "nand.hh"

static void setup_uart ():
	cpm_start_uart0 ()
	gpio_as_uart0 ()
	UART0_IER = 0
	UART0_FCR = 0
	UART0_MCR = 0
	UART0_SIRCR = 0
	UART0_UACR = 0
	UART0_UMR = 16
	UART0_LCR = UARTLCR_WLEN_8 | UARTLCR_STOP1 | UARTLCR_DLAB
	unsigned const baud = 57600
	unsigned uart_div = 12000000 / 16 / baud
	UART0_DLHR = (uart_div >> 8) & 0xff
	UART0_DLLR = uart_div & 0xff
	UART0_LCR = UARTLCR_WLEN_8 | UARTLCR_STOP1
	UART0_FCR = UARTFCR_UUE | UARTFCR_FE | UARTFCR_RFLS | UARTFCR_TFLS
	debug ("\n\nNand-boot: serial port initialized\n")

extern "C":
	void nandboot_start ():
		unsigned base = 0x18000000 + 0xa0000000
		data = (volatile char *)base
		command = (volatile char *)(base + 0x8000)
		address = (volatile char *)(base + 0x10000)
		pll_init ()
		cpm_start_all ()
		gpio_as_sdram_16bit ()
		gpio_as_nand ()
		setup_sdram ()
		setup_uart ()
		reset ()
		// Load contents of nand flash (from 0x4000) into 0xa0600000;
		unsigned a = 0x4000
		unsigned target = 0xa0600000
		while read (a, (char *)target):
			a += 0x200
			target += 0x200
		// Tell about what'll happen.
		debug ("Jumping to a0600000:\n")
		for unsigned d = 0; d < 0x40; ++d:
			debug (" ")
			debug_num (((char *)0xa0600000)[d] & 0xff, 16, 2)
		debug ('\n')
		// Wait for the serial port to finish.
		while !(UART0_LSR & UARTLSR_TEMT):
		// Then jump to 0xa0600000.
		((void (*)())0xa0600000) ()

unsigned char stack[0x1000]

unsigned __gxx_personality_v0