/*
 * zipl - zSeries Initial Program Loader tool
 *
 * Main program for stage3 bootloader
 *
 * Copyright IBM Corp. 2013, 2018
 *
 * s390-tools is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#include "libc.h"
#include "s390.h"
#include "stage3.h"
#include "error.h"

#define for_each_rb_entry(entry, rb) \
	for (entry = rb->entries; \
	     (void *) entry + sizeof(*entry) <= (void *) rb + rb->len; \
	     entry++)

static const char *msg_sipl_inval = "Secure boot failure: invalid load address";
static const char *msg_sipl_unverified = "Secure boot failure: unverified load address";

static unsigned char ebc_037[256] = {
/* 0x00  NUL   SOH   STX   ETX  *SEL    HT  *RNL   DEL */
	0x00, 0x01, 0x02, 0x03, 0x07, 0x09, 0x07, 0x7F,
/* 0x08  -GE  -SPS  -RPT    VT    FF    CR    SO    SI */
	0x07, 0x07, 0x07, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
/* 0x10  DLE   DC1   DC2   DC3  -RES   -NL    BS  -POC
                                -ENP  ->LF             */
	0x10, 0x11, 0x12, 0x13, 0x07, 0x0A, 0x08, 0x07,
/* 0x18  CAN    EM  -UBS  -CU1  -IFS  -IGS  -IRS  -ITB
                                                  -IUS */
	0x18, 0x19, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
/* 0x20  -DS  -SOS    FS  -WUS  -BYP    LF   ETB   ESC
                                -INP                   */
	0x07, 0x07, 0x1C, 0x07, 0x07, 0x0A, 0x17, 0x1B,
/* 0x28  -SA  -SFE   -SM  -CSP  -MFA   ENQ   ACK   BEL
                     -SW                               */
	0x07, 0x07, 0x07, 0x07, 0x07, 0x05, 0x06, 0x07,
/* 0x30 ----  ----   SYN   -IR   -PP  -TRN  -NBS   EOT */
	0x07, 0x07, 0x16, 0x07, 0x07, 0x07, 0x07, 0x04,
/* 0x38 -SBS   -IT  -RFF  -CU3   DC4   NAK  ----   SUB */
	0x07, 0x07, 0x07, 0x07, 0x14, 0x15, 0x07, 0x1A,
/* 0x40   SP   RSP           ä              ----       */
	0x20, 0xFF, 0x83, 0x84, 0x85, 0xA0, 0x07, 0x86,
/* 0x48                      .     <     (     +     | */
	0x87, 0xA4, 0x9B, 0x2E, 0x3C, 0x28, 0x2B, 0x7C,
/* 0x50    &                                      ---- */
	0x26, 0x82, 0x88, 0x89, 0x8A, 0xA1, 0x8C, 0x07,
/* 0x58          ß     !     $     *     )     ;       */
	0x8D, 0xE1, 0x21, 0x24, 0x2A, 0x29, 0x3B, 0xAA,
/* 0x60    -     /  ----     Ä  ----  ----  ----       */
	0x2D, 0x2F, 0x07, 0x8E, 0x07, 0x07, 0x07, 0x8F,
/* 0x68             ----     ,     %     _     >     ? */
	0x80, 0xA5, 0x07, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
/* 0x70  ---        ----  ----  ----  ----  ----  ---- */
	0x07, 0x90, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
/* 0x78    *     `     :     #     @     '     =     " */
	0x70, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
/* 0x80    *     a     b     c     d     e     f     g */
	0x07, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
/* 0x88    h     i              ----  ----  ----       */
	0x68, 0x69, 0xAE, 0xAF, 0x07, 0x07, 0x07, 0xF1,
/* 0x90    °     j     k     l     m     n     o     p */
	0xF8, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
/* 0x98    q     r                    ----        ---- */
	0x71, 0x72, 0xA6, 0xA7, 0x91, 0x07, 0x92, 0x07,
/* 0xA0          ~     s     t     u     v     w     x */
	0xE6, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
/* 0xA8    y     z              ----  ----  ----  ---- */
	0x79, 0x7A, 0xAD, 0xAB, 0x07, 0x07, 0x07, 0x07,
/* 0xB0    ^                    ----     §  ----       */
	0x5E, 0x9C, 0x9D, 0xFA, 0x07, 0x07, 0x07, 0xAC,
/* 0xB8       ----     [     ]  ----  ----  ----  ---- */
	0xAB, 0x07, 0x5B, 0x5D, 0x07, 0x07, 0x07, 0x07,
/* 0xC0    {     A     B     C     D     E     F     G */
	0x7B, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
/* 0xC8    H     I  ----           ö              ---- */
	0x48, 0x49, 0x07, 0x93, 0x94, 0x95, 0xA2, 0x07,
/* 0xD0    }     J     K     L     M     N     O     P */
	0x7D, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
/* 0xD8    Q     R  ----           ü                   */
	0x51, 0x52, 0x07, 0x96, 0x81, 0x97, 0xA3, 0x98,
/* 0xE0    \           S     T     U     V     W     X */
	0x5C, 0xF6, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
/* 0xE8    Y     Z        ----     Ö  ----  ----  ---- */
	0x59, 0x5A, 0xFD, 0x07, 0x99, 0x07, 0x07, 0x07,
/* 0xF0    0     1     2     3     4     5     6     7 */
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
/* 0xF8    8     9  ----  ----     Ü  ----  ----  ---- */
	0x38, 0x39, 0x07, 0x07, 0x9A, 0x07, 0x07, 0x07
};

static unsigned char ebc_500[256] = {
/* 0x00  NUL   SOH   STX   ETX  *SEL    HT  *RNL   DEL */
	0x00, 0x01, 0x02, 0x03, 0x07, 0x09, 0x07, 0x7F,
/* 0x08  -GE  -SPS  -RPT    VT    FF    CR    SO    SI */
	0x07, 0x07, 0x07, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
/* 0x10  DLE   DC1   DC2   DC3  -RES   -NL    BS  -POC
                                -ENP  ->LF             */
	0x10, 0x11, 0x12, 0x13, 0x07, 0x0A, 0x08, 0x07,
/* 0x18  CAN    EM  -UBS  -CU1  -IFS  -IGS  -IRS  -ITB
                                                  -IUS */
	0x18, 0x19, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
/* 0x20  -DS  -SOS    FS  -WUS  -BYP    LF   ETB   ESC
                                -INP                   */
	0x07, 0x07, 0x1C, 0x07, 0x07, 0x0A, 0x17, 0x1B,
/* 0x28  -SA  -SFE   -SM  -CSP  -MFA   ENQ   ACK   BEL
                     -SW                               */
	0x07, 0x07, 0x07, 0x07, 0x07, 0x05, 0x06, 0x07,
/* 0x30 ----  ----   SYN   -IR   -PP  -TRN  -NBS   EOT */
	0x07, 0x07, 0x16, 0x07, 0x07, 0x07, 0x07, 0x04,
/* 0x38 -SBS   -IT  -RFF  -CU3   DC4   NAK  ----   SUB */
	0x07, 0x07, 0x07, 0x07, 0x14, 0x15, 0x07, 0x1A,
/* 0x40   SP   RSP           ä              ----       */
	0x20, 0xFF, 0x83, 0x84, 0x85, 0xA0, 0x07, 0x86,
/* 0x48                      .     <     (     +     | */
	0x87, 0xA4, 0x9B, 0x2E, 0x3C, 0x28, 0x2B, 0x7C,
/* 0x50    &                                      ---- */
	0x26, 0x82, 0x88, 0x89, 0x8A, 0xA1, 0x8C, 0x07,
/* 0x58          ß     !     $     *     )     ;       */
	0x8D, 0xE1, 0x21, 0x24, 0x2A, 0x29, 0x3B, 0xAA,
/* 0x60    -     /  ----     Ä  ----  ----  ----       */
	0x2D, 0x2F, 0x07, 0x8E, 0x07, 0x07, 0x07, 0x8F,
/* 0x68             ----     ,     %     _     >     ? */
	0x80, 0xA5, 0x07, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
/* 0x70  ---        ----  ----  ----  ----  ----  ---- */
	0x07, 0x90, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
/* 0x78    *     `     :     #     @     '     =     " */
	0x70, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
/* 0x80    *     a     b     c     d     e     f     g */
	0x07, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
/* 0x88    h     i              ----  ----  ----       */
	0x68, 0x69, 0xAE, 0xAF, 0x07, 0x07, 0x07, 0xF1,
/* 0x90    °     j     k     l     m     n     o     p */
	0xF8, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
/* 0x98    q     r                    ----        ---- */
	0x71, 0x72, 0xA6, 0xA7, 0x91, 0x07, 0x92, 0x07,
/* 0xA0          ~     s     t     u     v     w     x */
	0xE6, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
/* 0xA8    y     z              ----  ----  ----  ---- */
	0x79, 0x7A, 0xAD, 0xAB, 0x07, 0x07, 0x07, 0x07,
/* 0xB0    ^                    ----     §  ----       */
	0x5E, 0x9C, 0x9D, 0xFA, 0x07, 0x07, 0x07, 0xAC,
/* 0xB8       ----     [     ]  ----  ----  ----  ---- */
	0xAB, 0x07, 0x5B, 0x5D, 0x07, 0x07, 0x07, 0x07,
/* 0xC0    {     A     B     C     D     E     F     G */
	0x7B, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
/* 0xC8    H     I  ----           ö              ---- */
	0x48, 0x49, 0x07, 0x93, 0x94, 0x95, 0xA2, 0x07,
/* 0xD0    }     J     K     L     M     N     O     P */
	0x7D, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
/* 0xD8    Q     R  ----           ü                   */
	0x51, 0x52, 0x07, 0x96, 0x81, 0x97, 0xA3, 0x98,
/* 0xE0    \           S     T     U     V     W     X */
	0x5C, 0xF6, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
/* 0xE8    Y     Z        ----     Ö  ----  ----  ---- */
	0x59, 0x5A, 0xFD, 0x07, 0x99, 0x07, 0x07, 0x07,
/* 0xF0    0     1     2     3     4     5     6     7 */
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
/* 0xF8    8     9  ----  ----     Ü  ----  ----  ---- */
	0x38, 0x39, 0x07, 0x07, 0x9A, 0x07, 0x07, 0x07
};

static void ebcdic_to_ascii(unsigned char *target, unsigned char *source,
		     unsigned int l)
{
	unsigned char *ebc;
	unsigned int i;

	ebc = is_zvm() ? ebc_037 : ebc_500;
	for (i = 0; i < l; i++)
			target[i] = ebc[source[i]];
}

static void
start_kernel(void)
{
	struct psw_t *psw = &S390_lowcore.program_new_psw;
	unsigned long addr, code;

	/* Setup program check handler */
	psw->mask = 0x000000180000000ULL;
	code = 1;

	asm volatile(
		/* Setup program check handler */
		"       larl    %[addr],.no_diag308\n"
		"       stg     %[addr],8(%[psw])\n"
		"       diag    %[code],%[code],0x308\n"
		".no_diag308:\n"
		"       sam31\n"
		"       sr      %r1,%r1\n"
		"       sr      %r2,%r2\n"
		"       sigp    %r1,%r2,0x12\n"
		"       lpsw    0\n"
		: [addr] "=&d" (addr),
		  [code] "+&d" (code)
		: [psw] "a" (psw) );
}

unsigned int
is_verified_address(unsigned long image_addr)
{
	struct ipl_rb_component_entry *comp;
	struct ipl_rb_components *comps;
	struct ipl_pl_hdr *pl_hdr;
	struct ipl_rl_hdr *rl_hdr;
	struct ipl_rb_hdr *rb_hdr;
	unsigned long tmp;
	void *rl_end;

	/*
	 * There is an IPL report, to find it load the pointer to the
	 * IPL parameter information block from lowcore and skip past
	 * the IPL parameter list, then align the address to a double
	 * word boundary.
	 */
	tmp = (unsigned long) S390_lowcore.ipl_parmblock_ptr;
	pl_hdr = (struct ipl_pl_hdr *) tmp;
	tmp = (tmp + pl_hdr->len + 7) & -8UL;
	rl_hdr = (struct ipl_rl_hdr *) tmp;
	/* Walk through the IPL report blocks in the IPL Report list */
	comps = NULL;
	rl_end = (void *) rl_hdr + rl_hdr->len;
	rb_hdr = (void *) rl_hdr + sizeof(*rl_hdr);
	while ((void *) rb_hdr + sizeof(*rb_hdr) < rl_end &&
	       (void *) rb_hdr + rb_hdr->len <= rl_end) {
		switch (rb_hdr->rbt) {
		case IPL_RBT_COMPONENTS:
			comps = (struct ipl_rb_components *) rb_hdr;
			break;
		default:
			break;
		}

		rb_hdr = (void *) rb_hdr + rb_hdr->len;
	}
	for_each_rb_entry(comp, comps) {
		if (image_addr == comp->addr &&
		    comp->flags & IPL_RB_COMPONENT_FLAG_SIGNED &&
		    comp->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
			return 1;
	}
	return 0;
}

unsigned int
secure_boot_enabled()
{
	struct ipl_pl_hdr *pl_hdr;
	unsigned long tmp;

	tmp = (unsigned long) S390_lowcore.ipl_parmblock_ptr;
	pl_hdr = (struct ipl_pl_hdr *) tmp;

	return pl_hdr->flags & IPL_FLAG_SECURE;
}

void start(void)
{
	unsigned int subchannel_id;
	unsigned char *cextra = (unsigned char *)COMMAND_LINE_EXTRA;
	unsigned char *command_line =  (unsigned char *)COMMAND_LINE;
	unsigned int begin = 0, end = 0, length = 0;

	/*
	 * IPL process is secure we have to use default IPL values and
	 * check if the psw jump address is within at the start of a
	 * verified component. If it is not IPL is aborted.
	 */
	if (secure_boot_enabled()) {
		if (_image_addr != DEFAULT_IMAGE_ADDR ||
		    _load_psw != DEFAULT_PSW_LOAD)
			panic(ESECUREBOOT, "%s", msg_sipl_inval);

		if (!is_verified_address(_load_psw & PSW_ADDR_MASK))
			panic(ESECUREBOOT, "%s", msg_sipl_unverified);
	}
	/*
	 * cut the kernel header
	 */
	memmove((void *)_image_addr,
		(void *)_image_addr + KERNEL_HEADER_SIZE,
		_image_len - KERNEL_HEADER_SIZE);

	/* store subchannel ID into low core and into new kernel space */
	subchannel_id = S390_lowcore.subchannel_id;
	*(unsigned int *)__LC_IPLDEV = subchannel_id;
	*(unsigned int *)IPL_DEVICE = subchannel_id;

	/* if valid command line is given, copy it into new kernel space */
	if (_parm_addr != UNSPECIFIED_ADDRESS) {
		memcpy((void *)COMMAND_LINE,
		       (void *)(unsigned long *)_parm_addr, COMMAND_LINE_SIZE);
		/* terminate \0 */
		*(char *)(COMMAND_LINE + COMMAND_LINE_SIZE - 1) = 0;
	}

	/* convert extra parameter to ascii */
	if (!_extra_parm || !*cextra)
		goto noextra;

	/* Handle extra kernel parameters specified in DASD boot menu. */
	ebcdic_to_ascii(cextra, cextra, COMMAND_LINE_SIZE);

	/* remove leading whitespace */
	while (begin <= COMMAND_LINE_SIZE && cextra[begin] == 0x20)
		begin++;

	/* determine length of extra parameter */
	while (length <= COMMAND_LINE_SIZE && cextra[length] != 0)
		length++;

	/* find end of original parm line */
	while (command_line[end] != 0)
		end++;

	/*
	 * if extra parm string starts with '=' replace original string,
	 * else append
	 */
	if (cextra[begin] == 0x3d) {
		memcpy((void *)COMMAND_LINE, (void *)(cextra + begin),
		       length);
	} else {
		/* check if length is within max value */
		length = (end + 1 + length <= COMMAND_LINE_SIZE) ? length :
			(COMMAND_LINE_SIZE - end - 1);
		/* add blank */
		command_line[end] = 0x20;
		end++;
		/* append string */
		memcpy((void *)(command_line + end),
		       (void *)(cextra + begin), length);
		/* terminate 0 */
		command_line[end + length] = 0;
	}

noextra:
	/* copy initrd start address and size intop new kernle space */
	*(unsigned long long *)INITRD_START = _initrd_addr;
	*(unsigned long long *)INITRD_SIZE = _initrd_len;

	/* store address of new kernel to 0 to be able to start it */
	*(unsigned long long *)0 = _load_psw;

	kdump_stage3();

	/* start new kernel */
	start_kernel();
}

void panic_notify(unsigned long UNUSED(rc))
{
}
