linux/arch/alpha/boot/tools/mkbb.iasm

// IronArc Port
// linux/arch/alpha/boot/tools/mkbb.c

// Includes: fcntl, unistd, stdlib, stdio
// MAXPARTITIONS = 8
// u8 = unsigned char (byte)
// u16 = unsigned short (ushort)
// u32 = unsigned int (uint)

// Struct disklabel
// u32 d_magic +0
// u16 d_type +4
// u16 d_subtype +6
// u8 d_typename[16] +8
// u8 d_packname[16] +24
// u32 d_secsize +40
// u32 d_nsectors +44
// u32 d_ntracks +48
// u32 d_ncylinders +52
// u32 d_secpercyl +56
// u32 d_secprtunit +60
// u16 d_sparespertrack +64
// u16 d_sparespercyl +66
// u32 d_acylinders +68
// u16 d_rpm +72
// u16 d_interleave +74
// u16 d_trackskew +76
// u16 d_cylskew +78
// u32 d_headswitch +80
// u32 d_trkseek +84
// u32 d_flags +88
// u32 d_drivedata[5] +92
// u32 d_spare[5] +112
// u32 d_magic2 +132
// u16 d_checksum +136
// u16 d_npartitions +138
// u32 d_bbsize +142
// u32 d_sbsize +146
// d_partition d_partitions[MAXPARTITIONS] +150
// Total size: 286 bytes

// Struct d_partition
// u32 p_size +0
// u32 p_offset +4
// u32 p_fsize +8
// u8 p_fstype +12
// u8 p_frag +13
// u16 p_cpg +15
// Total size: 17 bytes

// Union __bootblock
// Implicit struct #1 __u1 +0
// Implicit struct #2 __u2 +350
// char bootblock_bytes[512] +0
// unsigned long bootblock_quadwords[64] +0
// Total size: 862 bytes

// Implicit struct #1
// char __pad1[64] +0
// struct disklabel __label +64
// Total size: 350 bytes

// Implicit struct #2
// unsigned long __pad2[63] +0
// unsigned long __checksum +504
// Total size: 512 bytes

// bootblock_label == __u1.__label (offset +64)
// bootblock_checksum == __u2.checksum (offset +504)

// int main (int argc, char ** argv)
main:
	// Args: **argv on stack[1], argc on stack[0]

	// bootblock bootblock_from_disk;
	push 862
	call malloc

	// bootblock bootloader_image;
	push 862
	call malloc

	// int dev, fd;
	push 0
	push 0

	// int i;
	push 0

	// int nread;
	push 0

	// if (argc != 3)
	mov stack[6] eax
	ineql eax 3 eax
	cjmp main__argc_ineq_3_true eax
	mov 0 eax

	// dev = open(argv[1], O_RDWR)
	push 1
	mov stack[7] ebx
	mov *ebx ebx
	addl ebx 1 ebx
	mov *ebx ebx
	call open
	mov stack[0] stack[3]
	pop nul

	// if (dev < 0)
	mov stack[2] eax
	ltl eax 0 eax
	cjmp main__dev_lt_0_true eax
	mov 0 eax

	// fd = open(argv[2], O_RDONLY)
	push 0
	mov stack[7] ebx
	mov *ebx ebx
	addl ebx 2 ebx
	mov *ebx ebx
	call open
	mov stack[0] stack[4]
	pop nul

	// if (fd < 0)
	mov stack[3] eax
	ltl eax 0 eax
	cjmp main__fd_lt_0_true
	mov 0 eax

	// nread = read(fd, &bootloader_image, sizeof(bootblock))
	push 862
	push stack[5]
	push stack[5]
	call read
	mov stack[0] stack[1]
	pop nul

	// if (nread != sizeof(bootblock))
	mov stack[0] eax
	ineql eax 862 eax
	cjmp main__nread_ineq_sizeof_bootblock_true eax
	mov 0 eax

	// nread = read(dev, &bootblock_from_disk, sizeof(bootblock));
	push 862
	push stack[6]
	push stack[4]
	call read
	mov stack[0] stack[1]
	pop nul

	// if (nread != sizeof(bootblock))
	mov stack[0] eax
	ineql eax 862 eax
	cjmp main__nread_ineql_sizeof_bootblock_2_true eax
	mov 0 eax

	// bootloader_image.bootblock_label = bootblock_from_disk.bootblock_label;
	mov stack[4] eax
	mov stack[5] ebx
	addl eax 64 eax
	addl ebx 64 ebx
	mov 286 ecx
	main__loop_main:
	mov *ebx+1 *eax+1
	decl ecx
	cjmp main__loop_main ecx
	mov 0 eax
	mov 0 ebx

	// bootloader_image.bootblock_checksum = 0;
	mov stack[4] eax
	addl eax 504 eax
	mov 0 *eax+8

	// for (i = 0; i < 63; i++)
	// bootloader_image.bootblock_checksum += bootloader_image.bootblock_quadwords[i];
	main__loop2_main:
	mov stack[4] ebx
	mov stack[1] ecx
	multl ecx 8 ecx
	addl ebx ecx ebx
	addl *eax+8 *ebx+8 *eax
	incl stack[2]
	mov stack[2] ecx
	ltl ecx 63 ecx
	notl ecx ecx
	cjmp main__loop2_main ecx
	mov 0 eax
	mov 0 ebx
	mov 0 ecx

	// lseek(dev, 0L, SEEK_SET);
	push 0
	push 0
	push stack[4]
	call lseek

	// if (write(dev, &bootloader_image, sizeof(bootblock)) != sizeof (bootblock))
	push 862
	push stack[5]
	push stack[4]
	call write
	pop eax
	ineql eax 862 eax
	cjmp main__write_dev_bootloader_image_sizeof_bootblock_ineq_sizeof_bootblock eax
	mov 0 eax

	// close(fd);
	push stack[3]
	call close

	// close(dev)
	push stack[2]
	call close

	// Cleanup
	pop nul
	pop nul
	pop nul
	pop nul
	pop nul
	pop nul
	pop nul
	pop nul

	// exit(0);
	push 0
	call exit

	main__argc_ineq_3_true:
		// fprintf(stderr, "Usage: %s device lxboot\n", argv[0]);
		mov stack[7] ebx
		mov *ebx ebx
		mov *ebx ebx
		push ebx
		push "Usage: %s device lxboot\n"
		push 2
		call fprintf

		// exit(0);
		push 0
		call exit

	main__dev_lt_0_true:
		// perror(argv[1]);
		mov stack[7] ebx
		mov *ebx ebx
		addl ebx 1 ebx
		mov *ebx ebx
		push ebx
		call perror

		// exit(0);
		push 0
		call exit

	main__fd_lt_0_true:
		// perror(argv[2])
		mov stack[7] eax
		mov *eax eax
		addl eax 2 eax
		mov *eax eax
		call perror

		// close(dev)
		push stack[2]
		call close

		// exit(0)
		push 0
		call exit

	main__nread_ineq_sizeof_bootblock_true:
		// perror("lxboot read");
		push "lxboot read"
		call perror

		// fprintf(stderr, "expected %zd, got %d\n", sizeof(bootblock), nread);
		push stack[0]
		push 862
		push "expected %zd, got %d\n"
		push 2
		call fprintf

		// exit(0);
		push 0
		call exit

	main__nread_ineq_sizeof_bootblock_2_true:
		// perror("bootblock read");
		push "bootblock read"
		call perror

		// fprintf(stderr, "expected %zd, got %d\n, sizeof(bootblock), nread);
		push stack[0]
		push 862
		push "expected %zd, got %d\n"
		push 2
		call fprintf

		// exit(0);
		push 0
		call exit

	main__write_dev_bootloader_image_sizeof_bootblock_ineq_sizeof_bootblock
		// perror("bootblock write");
		push "bootblock write"
		call perror

		// exit(0);
		push 0
		call exit