--- /dev/null
+// 16bit code to access floppy drives.
+//
+// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
+// Copyright (C) 2002 MandrakeSoft S.A.
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "types.h" // u8
+#include "disk.h" // DISK_RET_SUCCESS
+#include "config.h" // CONFIG_FLOPPY
+#include "biosvar.h" // SET_BDA
+#include "util.h" // wait_irq
+#include "cmos.h" // inb_cmos
+#include "pic.h" // eoi_pic1
+#include "bregs.h" // struct bregs
+#include "boot.h" // boot_add_floppy
+#include "pci.h" // pci_to_bdf
+#include "pci_ids.h" // PCI_CLASS_BRIDGE_ISA
+
+#define FLOPPY_SIZE_CODE 0x02 // 512 byte sectors
+#define FLOPPY_DATALEN 0xff // Not used - because size code is 0x02
+#define FLOPPY_MOTOR_TICKS 37 // ~2 seconds
+#define FLOPPY_FILLBYTE 0xf6
+#define FLOPPY_GAPLEN 0x1B
+#define FLOPPY_FORMAT_GAPLEN 0x6c
+
+// New diskette parameter table adding 3 parameters from IBM
+// Since no provisions are made for multiple drive types, most
+// values in this table are ignored. I set parameters for 1.44M
+// floppy here
+struct floppy_ext_dbt_s diskette_param_table2 VAR16VISIBLE = {
+ .dbt = {
+ .specify1 = 0xAF, // step rate 12ms, head unload 240ms
+ .specify2 = 0x02, // head load time 4ms, DMA used
+ .shutoff_ticks = FLOPPY_MOTOR_TICKS, // ~2 seconds
+ .bps_code = FLOPPY_SIZE_CODE,
+ .sectors = 18,
+ .interblock_len = FLOPPY_GAPLEN,
+ .data_len = FLOPPY_DATALEN,
+ .gap_len = FLOPPY_FORMAT_GAPLEN,
+ .fill_byte = FLOPPY_FILLBYTE,
+ .settle_time = 0x0F, // 15ms
+ .startup_time = 0x08, // 1 second
+ },
+ .max_track = 79, // maximum track
+ .data_rate = 0, // data transfer rate
+ .drive_type = 4, // drive type in cmos
+};
+
+// Since no provisions are made for multiple drive types, most
+// values in this table are ignored. I set parameters for 1.44M
+// floppy here
+struct floppy_dbt_s diskette_param_table VAR16FIXED(0xefc7) = {
+ .specify1 = 0xAF,
+ .specify2 = 0x02,
+ .shutoff_ticks = FLOPPY_MOTOR_TICKS,
+ .bps_code = FLOPPY_SIZE_CODE,
+ .sectors = 18,
+ .interblock_len = FLOPPY_GAPLEN,
+ .data_len = FLOPPY_DATALEN,
+ .gap_len = FLOPPY_FORMAT_GAPLEN,
+ .fill_byte = FLOPPY_FILLBYTE,
+ .settle_time = 0x0F,
+ .startup_time = 0x08,
+};
+
+struct floppyinfo_s {
+ struct chs_s chs;
+ u8 config_data;
+ u8 media_state;
+};
+
+struct floppyinfo_s FloppyInfo[] VAR16VISIBLE = {
+ // Unknown
+ { {0, 0, 0}, 0x00, 0x00},
+ // 1 - 360KB, 5.25" - 2 heads, 40 tracks, 9 sectors
+ { {2, 40, 9}, 0x00, 0x25},
+ // 2 - 1.2MB, 5.25" - 2 heads, 80 tracks, 15 sectors
+ { {2, 80, 15}, 0x00, 0x25},
+ // 3 - 720KB, 3.5" - 2 heads, 80 tracks, 9 sectors
+ { {2, 80, 9}, 0x00, 0x17},
+ // 4 - 1.44MB, 3.5" - 2 heads, 80 tracks, 18 sectors
+ { {2, 80, 18}, 0x00, 0x17},
+ // 5 - 2.88MB, 3.5" - 2 heads, 80 tracks, 36 sectors
+ { {2, 80, 36}, 0xCC, 0xD7},
+ // 6 - 160k, 5.25" - 1 heads, 40 tracks, 8 sectors
+ { {1, 40, 8}, 0x00, 0x27},
+ // 7 - 180k, 5.25" - 1 heads, 40 tracks, 9 sectors
+ { {1, 40, 9}, 0x00, 0x27},
+ // 8 - 320k, 5.25" - 2 heads, 40 tracks, 8 sectors
+ { {2, 40, 8}, 0x00, 0x27},
+};
+
+struct drive_s *
+init_floppy(int floppyid, int ftype)
+{
+ if (ftype <= 0 || ftype >= ARRAY_SIZE(FloppyInfo)) {
+ dprintf(1, "Bad floppy type %d\n", ftype);
+ return NULL;
+ }
+
+ struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
+ if (!drive_g) {
+ warn_noalloc();
+ return NULL;
+ }
+ memset(drive_g, 0, sizeof(*drive_g));
+ drive_g->cntl_id = floppyid;
+ drive_g->type = DTYPE_FLOPPY;
+ drive_g->blksize = DISK_SECTOR_SIZE;
+ drive_g->floppy_type = ftype;
+ drive_g->sectors = (u64)-1;
+
+ memcpy(&drive_g->lchs, &FloppyInfo[ftype].chs
+ , sizeof(FloppyInfo[ftype].chs));
+ return drive_g;
+}
+
+static void
+addFloppy(int floppyid, int ftype)
+{
+ struct drive_s *drive_g = init_floppy(floppyid, ftype);
+ if (!drive_g)
+ return;
+ char *desc = znprintf(MAXDESCSIZE, "Floppy [drive %c]", 'A' + floppyid);
+ struct pci_device *pci = pci_find_class(PCI_CLASS_BRIDGE_ISA); /* isa-to-pci bridge */
+ int prio = bootprio_find_fdc_device(pci, PORT_FD_BASE, floppyid);
+ boot_add_floppy(drive_g, desc, prio);
+}
+
+void
+floppy_setup(void)
+{
+ if (! CONFIG_FLOPPY)
+ return;
+ dprintf(3, "init floppy drives\n");
+
+ if (CONFIG_COREBOOT) {
+ // XXX - disable floppies on coreboot for now.
+ } else {
+ u8 type = inb_cmos(CMOS_FLOPPY_DRIVE_TYPE);
+ if (type & 0xf0)
+ addFloppy(0, type >> 4);
+ if (type & 0x0f)
+ addFloppy(1, type & 0x0f);
+ }
+
+ outb(0x02, PORT_DMA1_MASK_REG);
+
+ enable_hwirq(6, FUNC16(entry_0e));
+}
+
+// Find a floppy type that matches a given image size.
+int
+find_floppy_type(u32 size)
+{
+ int i;
+ for (i=1; i<ARRAY_SIZE(FloppyInfo); i++) {
+ struct chs_s *c = &FloppyInfo[i].chs;
+ if (c->cylinders * c->heads * c->spt * DISK_SECTOR_SIZE == size)
+ return i;
+ }
+ return -1;
+}
+
+
+/****************************************************************
+ * Low-level floppy IO
+ ****************************************************************/
+
+static void
+floppy_reset_controller(void)
+{
+ // Reset controller
+ u8 val8 = inb(PORT_FD_DOR);
+ outb(val8 & ~0x04, PORT_FD_DOR);
+ outb(val8 | 0x04, PORT_FD_DOR);
+
+ // Wait for controller to come out of reset
+ while ((inb(PORT_FD_STATUS) & 0xc0) != 0x80)
+ ;
+}
+
+static int
+wait_floppy_irq(void)
+{
+ ASSERT16();
+ u8 v;
+ for (;;) {
+ if (!GET_BDA(floppy_motor_counter))
+ return -1;
+ v = GET_BDA(floppy_recalibration_status);
+ if (v & FRS_TIMEOUT)
+ break;
+ // Could use wait_irq() here, but that causes issues on
+ // bochs, so use yield() instead.
+ yield();
+ }
+
+ v &= ~FRS_TIMEOUT;
+ SET_BDA(floppy_recalibration_status, v);
+ return 0;
+}
+
+static void
+floppy_prepare_controller(u8 floppyid)
+{
+ CLEARBITS_BDA(floppy_recalibration_status, FRS_TIMEOUT);
+
+ // turn on motor of selected drive, DMA & int enabled, normal operation
+ u8 prev_reset = inb(PORT_FD_DOR) & 0x04;
+ u8 dor = 0x10;
+ if (floppyid)
+ dor = 0x20;
+ dor |= 0x0c;
+ dor |= floppyid;
+ outb(dor, PORT_FD_DOR);
+
+ // reset the disk motor timeout value of INT 08
+ SET_BDA(floppy_motor_counter, FLOPPY_MOTOR_TICKS);
+
+ // wait for drive readiness
+ while ((inb(PORT_FD_STATUS) & 0xc0) != 0x80)
+ ;
+
+ if (!prev_reset)
+ wait_floppy_irq();
+}
+
+static int
+floppy_pio(u8 *cmd, u8 cmdlen)
+{
+ floppy_prepare_controller(cmd[1] & 1);
+
+ // send command to controller
+ u8 i;
+ for (i=0; i<cmdlen; i++)
+ outb(cmd[i], PORT_FD_DATA);
+
+ int ret = wait_floppy_irq();
+ if (ret) {
+ floppy_reset_controller();
+ return -1;
+ }
+
+ return 0;
+}
+
+static int
+floppy_cmd(struct disk_op_s *op, u16 count, u8 *cmd, u8 cmdlen)
+{
+ // es:bx = pointer to where to place information from diskette
+ u32 addr = (u32)op->buf_fl;
+
+ // check for 64K boundary overrun
+ u16 end = count - 1;
+ u32 last_addr = addr + end;
+ if ((addr >> 16) != (last_addr >> 16))
+ return DISK_RET_EBOUNDARY;
+
+ u8 mode_register = 0x4a; // single mode, increment, autoinit disable,
+ if (cmd[0] == 0xe6)
+ // read
+ mode_register = 0x46;
+
+ //DEBUGF("floppy dma c2\n");
+ outb(0x06, PORT_DMA1_MASK_REG);
+ outb(0x00, PORT_DMA1_CLEAR_FF_REG); // clear flip-flop
+ outb(addr, PORT_DMA_ADDR_2);
+ outb(addr>>8, PORT_DMA_ADDR_2);
+ outb(0x00, PORT_DMA1_CLEAR_FF_REG); // clear flip-flop
+ outb(end, PORT_DMA_CNT_2);
+ outb(end>>8, PORT_DMA_CNT_2);
+
+ // port 0b: DMA-1 Mode Register
+ // transfer type=write, channel 2
+ outb(mode_register, PORT_DMA1_MODE_REG);
+
+ // port 81: DMA-1 Page Register, channel 2
+ outb(addr>>16, PORT_DMA_PAGE_2);
+
+ outb(0x02, PORT_DMA1_MASK_REG); // unmask channel 2
+
+ int ret = floppy_pio(cmd, cmdlen);
+ if (ret)
+ return DISK_RET_ETIMEOUT;
+
+ // check port 3f4 for accessibility to status bytes
+ if ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0)
+ return DISK_RET_ECONTROLLER;
+
+ // read 7 return status bytes from controller
+ u8 i;
+ for (i=0; i<7; i++) {
+ u8 v = inb(PORT_FD_DATA);
+ cmd[i] = v;
+ SET_BDA(floppy_return_status[i], v);
+ }
+
+ return DISK_RET_SUCCESS;
+}
+
+
+/****************************************************************
+ * Floppy media sense
+ ****************************************************************/
+
+static inline void
+set_diskette_current_cyl(u8 floppyid, u8 cyl)
+{
+ SET_BDA(floppy_track[floppyid], cyl);
+}
+
+static void
+floppy_drive_recal(u8 floppyid)
+{
+ // send Recalibrate command (2 bytes) to controller
+ u8 data[12];
+ data[0] = 0x07; // 07: Recalibrate
+ data[1] = floppyid; // 0=drive0, 1=drive1
+ floppy_pio(data, 2);
+
+ SETBITS_BDA(floppy_recalibration_status, 1<<floppyid);
+ set_diskette_current_cyl(floppyid, 0);
+}
+
+static int
+floppy_media_sense(struct drive_s *drive_g)
+{
+ // for now cheat and get drive type from CMOS,
+ // assume media is same as drive type
+
+ // ** config_data **
+ // Bitfields for diskette media control:
+ // Bit(s) Description (Table M0028)
+ // 7-6 last data rate set by controller
+ // 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps
+ // 5-4 last diskette drive step rate selected
+ // 00=0Ch, 01=0Dh, 10=0Eh, 11=0Ah
+ // 3-2 {data rate at start of operation}
+ // 1-0 reserved
+
+ // ** media_state **
+ // Bitfields for diskette drive media state:
+ // Bit(s) Description (Table M0030)
+ // 7-6 data rate
+ // 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps
+ // 5 double stepping required (e.g. 360kB in 1.2MB)
+ // 4 media type established
+ // 3 drive capable of supporting 4MB media
+ // 2-0 on exit from BIOS, contains
+ // 000 trying 360kB in 360kB
+ // 001 trying 360kB in 1.2MB
+ // 010 trying 1.2MB in 1.2MB
+ // 011 360kB in 360kB established
+ // 100 360kB in 1.2MB established
+ // 101 1.2MB in 1.2MB established
+ // 110 reserved
+ // 111 all other formats/drives
+
+ u8 ftype = GET_GLOBAL(drive_g->floppy_type);
+ SET_BDA(floppy_last_data_rate, GET_GLOBAL(FloppyInfo[ftype].config_data));
+ u8 floppyid = GET_GLOBAL(drive_g->cntl_id);
+ SET_BDA(floppy_media_state[floppyid]
+ , GET_GLOBAL(FloppyInfo[ftype].media_state));
+ return DISK_RET_SUCCESS;
+}
+
+static int
+check_recal_drive(struct drive_s *drive_g)
+{
+ u8 floppyid = GET_GLOBAL(drive_g->cntl_id);
+ if ((GET_BDA(floppy_recalibration_status) & (1<<floppyid))
+ && (GET_BDA(floppy_media_state[floppyid]) & FMS_MEDIA_DRIVE_ESTABLISHED))
+ // Media is known.
+ return DISK_RET_SUCCESS;
+
+ // Recalibrate drive.
+ floppy_drive_recal(floppyid);
+
+ // Sense media.
+ return floppy_media_sense(drive_g);
+}
+
+
+/****************************************************************
+ * Floppy handlers
+ ****************************************************************/
+
+static void
+lba2chs(struct disk_op_s *op, u8 *track, u8 *sector, u8 *head)
+{
+ u32 lba = op->lba;
+
+ u32 tmp = lba + 1;
+ u16 nlspt = GET_GLOBAL(op->drive_g->lchs.spt);
+ *sector = tmp % nlspt;
+
+ tmp /= nlspt;
+ u16 nlh = GET_GLOBAL(op->drive_g->lchs.heads);
+ *head = tmp % nlh;
+
+ tmp /= nlh;
+ *track = tmp;
+}
+
+// diskette controller reset
+static int
+floppy_reset(struct disk_op_s *op)
+{
+ u8 floppyid = GET_GLOBAL(op->drive_g->cntl_id);
+ set_diskette_current_cyl(floppyid, 0); // current cylinder
+ return DISK_RET_SUCCESS;
+}
+
+// Read Diskette Sectors
+static int
+floppy_read(struct disk_op_s *op)
+{
+ int res = check_recal_drive(op->drive_g);
+ if (res)
+ goto fail;
+
+ u8 track, sector, head;
+ lba2chs(op, &track, §or, &head);
+
+ // send read-normal-data command (9 bytes) to controller
+ u8 floppyid = GET_GLOBAL(op->drive_g->cntl_id);
+ u8 data[12];
+ data[0] = 0xe6; // e6: read normal data
+ data[1] = (head << 2) | floppyid; // HD DR1 DR2
+ data[2] = track;
+ data[3] = head;
+ data[4] = sector;
+ data[5] = FLOPPY_SIZE_CODE;
+ data[6] = sector + op->count - 1; // last sector to read on track
+ data[7] = FLOPPY_GAPLEN;
+ data[8] = FLOPPY_DATALEN;
+
+ res = floppy_cmd(op, op->count * DISK_SECTOR_SIZE, data, 9);
+ if (res)
+ goto fail;
+
+ if (data[0] & 0xc0) {
+ res = DISK_RET_ECONTROLLER;
+ goto fail;
+ }
+
+ // ??? should track be new val from return_status[3] ?
+ set_diskette_current_cyl(floppyid, track);
+ return DISK_RET_SUCCESS;
+fail:
+ op->count = 0; // no sectors read
+ return res;
+}
+
+// Write Diskette Sectors
+static int
+floppy_write(struct disk_op_s *op)
+{
+ int res = check_recal_drive(op->drive_g);
+ if (res)
+ goto fail;
+
+ u8 track, sector, head;
+ lba2chs(op, &track, §or, &head);
+
+ // send write-normal-data command (9 bytes) to controller
+ u8 floppyid = GET_GLOBAL(op->drive_g->cntl_id);
+ u8 data[12];
+ data[0] = 0xc5; // c5: write normal data
+ data[1] = (head << 2) | floppyid; // HD DR1 DR2
+ data[2] = track;
+ data[3] = head;
+ data[4] = sector;
+ data[5] = FLOPPY_SIZE_CODE;
+ data[6] = sector + op->count - 1; // last sector to write on track
+ data[7] = FLOPPY_GAPLEN;
+ data[8] = FLOPPY_DATALEN;
+
+ res = floppy_cmd(op, op->count * DISK_SECTOR_SIZE, data, 9);
+ if (res)
+ goto fail;
+
+ if (data[0] & 0xc0) {
+ if (data[1] & 0x02)
+ res = DISK_RET_EWRITEPROTECT;
+ else
+ res = DISK_RET_ECONTROLLER;
+ goto fail;
+ }
+
+ // ??? should track be new val from return_status[3] ?
+ set_diskette_current_cyl(floppyid, track);
+ return DISK_RET_SUCCESS;
+fail:
+ op->count = 0; // no sectors read
+ return res;
+}
+
+// Verify Diskette Sectors
+static int
+floppy_verify(struct disk_op_s *op)
+{
+ int res = check_recal_drive(op->drive_g);
+ if (res)
+ goto fail;
+
+ u8 track, sector, head;
+ lba2chs(op, &track, §or, &head);
+
+ // ??? should track be new val from return_status[3] ?
+ u8 floppyid = GET_GLOBAL(op->drive_g->cntl_id);
+ set_diskette_current_cyl(floppyid, track);
+ return DISK_RET_SUCCESS;
+fail:
+ op->count = 0; // no sectors read
+ return res;
+}
+
+// format diskette track
+static int
+floppy_format(struct disk_op_s *op)
+{
+ int ret = check_recal_drive(op->drive_g);
+ if (ret)
+ return ret;
+
+ u8 head = op->lba;
+
+ // send format-track command (6 bytes) to controller
+ u8 floppyid = GET_GLOBAL(op->drive_g->cntl_id);
+ u8 data[12];
+ data[0] = 0x4d; // 4d: format track
+ data[1] = (head << 2) | floppyid; // HD DR1 DR2
+ data[2] = FLOPPY_SIZE_CODE;
+ data[3] = op->count; // number of sectors per track
+ data[4] = FLOPPY_FORMAT_GAPLEN;
+ data[5] = FLOPPY_FILLBYTE;
+
+ ret = floppy_cmd(op, op->count * 4, data, 6);
+ if (ret)
+ return ret;
+
+ if (data[0] & 0xc0) {
+ if (data[1] & 0x02)
+ return DISK_RET_EWRITEPROTECT;
+ return DISK_RET_ECONTROLLER;
+ }
+
+ set_diskette_current_cyl(floppyid, 0);
+ return DISK_RET_SUCCESS;
+}
+
+int
+process_floppy_op(struct disk_op_s *op)
+{
+ if (!CONFIG_FLOPPY)
+ return 0;
+
+ switch (op->command) {
+ case CMD_RESET:
+ return floppy_reset(op);
+ case CMD_READ:
+ return floppy_read(op);
+ case CMD_WRITE:
+ return floppy_write(op);
+ case CMD_VERIFY:
+ return floppy_verify(op);
+ case CMD_FORMAT:
+ return floppy_format(op);
+ default:
+ op->count = 0;
+ return DISK_RET_EPARAM;
+ }
+}
+
+
+/****************************************************************
+ * HW irqs
+ ****************************************************************/
+
+// INT 0Eh Diskette Hardware ISR Entry Point
+void VISIBLE16
+handle_0e(void)
+{
+ debug_isr(DEBUG_ISR_0e);
+ if (! CONFIG_FLOPPY)
+ goto done;
+
+ if ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0) {
+ outb(0x08, PORT_FD_DATA); // sense interrupt status
+ while ((inb(PORT_FD_STATUS) & 0xc0) != 0xc0)
+ ;
+ do {
+ inb(PORT_FD_DATA);
+ } while ((inb(PORT_FD_STATUS) & 0xc0) == 0xc0);
+ }
+ // diskette interrupt has occurred
+ SETBITS_BDA(floppy_recalibration_status, FRS_TIMEOUT);
+
+done:
+ eoi_pic1();
+}
+
+// Called from int08 handler.
+void
+floppy_tick(void)
+{
+ if (! CONFIG_FLOPPY)
+ return;
+
+ // time to turn off drive(s)?
+ u8 fcount = GET_BDA(floppy_motor_counter);
+ if (fcount) {
+ fcount--;
+ SET_BDA(floppy_motor_counter, fcount);
+ if (fcount == 0)
+ // turn motor(s) off
+ outb(inb(PORT_FD_DOR) & 0xcf, PORT_FD_DOR);
+ }
+}
