00.lk-＞kernel(mtk)

mtk平台没有跑app/aboot/aboot.c  跑的是app/mt_boot/mt_boot.c

/ {

        model = "MT8167";

        compatible = "mediatek,mt8167";

        interrupt-parent = <&sysirq>;

        #address-cells = <2>;

        #size-cells = <2>;

        /* chosen */

        chosen {

                bootargs = "console=tty0 console=ttyS0,921600n1 \

                earlycon=uart8250,mmio32,0x11005000 vmalloc=496M \

                androidboot.hardware=mt8167 \

                firmware_class.path=/vendor/firmware loop.max_part=7";

        };

};

LK调用流程：

mt_boot_init

->boot_linux_from_storage

  ->tags_target_addr = get_tags_addr();

  ->bootargs_init((void *)tags_target_addr); //将dts chosen节点下的 bootargs子节点的字符串保存到g_cmdline

  ->boot_linux

   ->boot_linux_fdt        //继续设置属性

/vendor/mediatek/proprietary/bootable/bootloader/lk/app/mt_boot/bootargs.h

#define CMDLINE_LEN   2048

/vendor/mediatek/proprietary/bootable/bootloader/lk/app/mt_boot/bootargs.c

static char g_cmdline[CMDLINE_LEN];

static char *cmdline_tail = g_cmdline;

static char *cmdline_end = g_cmdline + CMDLINE_LEN;

void bootargs_init(void *fdt)

  ... ...

        /* Reset cmdline_tail */

        cmdline_tail = g_cmdline;

        offset = fdt_path_offset(fdt, "/chosen");  //dts chosen节点下的 bootargs子节点

        fdt_bootargs = fdt_getprop(fdt, offset, "bootargs", &len);  /vendor/mediatek/proprietary/bootable/bootloader/lk/lib/libfdt/fdt_ro.c

        assert(fdt_bootargs);

        n = snprintf(cmdline_tail, CMDLINE_LEN, "%s", (char *)fdt_bootargs);

        if (n < 0)

                dprintf(INFO, "snprintf error in %s:%d\n", __FILE__, __LINE__);

        else

                cmdline_tail += n;

  ... ...

}

static char g_cmdline[CMDLINE_LEN];

void cmdline_print(void){}

 ->cmd_len = strlen(g_cmdline);

 ->pal_log_err("g_cmdline size: %d\n", cmd_len);

 ->pal_log_err("cmdline: %s\n", temp_cmdline);

Line 1520: (190318_15:43:57.017)[1037]cmdline: console=tty0 console=ttyMT0,921600n1 root=/dev/ram earlycon=uart8250,mmio32,0x11005000 vmalloc=496Mandroidboot.hardware=mt8167 firmware_class.path=/vendor/firmware androidboot.verifiedbootstate=green bootopt=64S3,32N2,32N2 buildvariant=user androidboot.veritymode=enforcing printk.disable_uart=0 bootprof.pl_t=2244 bootprof.lk_t=1027 boot_reason=0 androidboot.serialno=0123456789ABCDEF androidboot.bootreason=power_key mrdump_ddrsv=no mrdump_rsvmem=0x56000000,0x400000,0x42100000,0x17b800,0x54000000,0x80000

/kernel-4.9-lc/init/main.c

asmlinkage __visible void __init start_kernel(void){}

 ->pr_notice("Kernel command line: %s\n", boot_command_line);

Line 1554: (190318_15:43:57.484)[    0.000000] <0>-(0)[0:swapper]Kernel command line: console=tty0 console=ttyMT0,921600n1 root=/dev/ram earlycon=uart8250,mmio32,0x11005000vmalloc=496M androidboot.hardware=mt8167 firmware_class.path=/vendor/firmware androidboot.verifiedbootstate=green bootopt=64S3,32N2,32N2 buildvariant=user androidboot.veritymode=enforcing printk.disable_uart=0 bootprof.pl_t=2244 bootprof.lk_t=1027 boot_reason=0 androidboot.serialno=0123456789ABCDEF androidboot.bootreason=power_key mrdump_ddrsv=no mrdump_rsvmem=0x56000000,0x400000,0x42100000,0x17b800,0x54000000,0x80000

 /kernel-4.19-lc/lib/cmdline.c

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

int get_option(char **str, int *pint) {     char *cur = *str;     if (!cur || !(*cur))         return 0;     *pint = simple_strtol(cur, str, 0);     if (cur == *str)         return 0;     if (**str == ',') {         (*str)++;         return 2;     }     if (**str == '-')         return 3;     return 1; } EXPORT_SYMBOL(get_option);

内核自带例子：

 /kernel-4.19-lc/arch/mips/kernel/mips-mt.c

1 2 3 4 5 6 7 8

static int __init maxvpes(char *str) {     get_option(&str, &vpelimit);     return 1; } __setup("maxvpes=", maxvpes)

我们在MTK平台实现的例子：

NVRAM：

LVDS_SELECT_FLAG可以通过SN工具先行写到nvram里面，然后通过读取nvram “proinfo”分区的数据保存到addr

unsigned char *addr;
unsigned long length = 512；
char *part_name = "proinfo";
part_dev_t *dev;
part_t *part;
dev = mt_part_get_device();
part = mt_part_get_partition(part_name);

start_addr = (u64)(part->start_sect) * dev->blkdev->blksz;
addr = (unsigned char *)malloc(length*sizeof(unsigned char));
len = dev->read(dev, start_addr, (uchar*)addr,length, part->part_id);

len = partition_read(part_name, sizeof(part_hdr_t), (uchar *)addr, (size_t)part_hdr->info.dsize);

if(len < 0){

    printf("Isaac [mboot_common_get_lvds_flag] len=%d\n",len);

   len = -EIO;

    goto exit;

}

LVDS_SELECT_FLAG= addr[64+40+40];

LK：

将LVDS_SELECT_FLAG添加到cmdline当中：

/vendor/mediatek/proprietary/bootable/bootloader/lk/app/mt_boot/mt_boot.c

extern int LVDS_SELECT_FLAG;//Isaac add

int boot_linux_fdt(void *kernel, unsigned *tags,

                   unsigned machtype,

                   void *ramdisk, unsigned ramdisk_sz)

{

  ...

  /* Append androidboot.serialno=xxxxyyyyzzzz in cmdline */

        snprintf(tmpbuf, TMPBUF_SIZE, "%s%s", "androidboot.serialno=", sn_buf);

        cmdline_append(tmpbuf);

        /*Isaac add lvds flag*/

        printf("Isaac [boot_linux_fdt] get LVDS_SELECT_FLAG=%d\n",LVDS_SELECT_FLAG);

        snprintf(tmpbuf, TMPBUF_SIZE, "%s%d", "lvds_select_flag=", LVDS_SELECT_FLAG);

        cmdline_append(tmpbuf);

}

KERNEL：

kernel-4.4\drivers\misc\mediatek\lcm\B116XAN023_LVDS\B116XAN023_LVDS.c

int LVDS_SELECT_FLAG=0;

#define FRAME_WIDTH  (1366)

#define FRAME_HEIGHT (768)

#define FRAME_WIDTH_MIPI  (1368)

#define FRAME_HEIGHT_MIPI (768)

static int __init get_lvds_select_flag(char *str)

{

        get_option(&str, &LVDS_SELECT_FLAG);

        //LVDS_SELECT_FLAG = simple_strtol(str, NULL, 0);

        return 1;

}

__setup("lvds_select_flag=", get_lvds_select_flag);   

static void lcm_get_params(LCM_PARAMS *params)

{

 printf("LK Isaac [lcm_get_params] LVDS_SELECT_FLAG=%d\n",LVDS_SELECT_FLAG);

 if(LVDS_SELECT_FLAG == 0x31)

 {

  printf("[LK/LCM] [lcm_get_params]->B116XAN023_LVDS enter\n");

  memset(params, 0, sizeof(LCM_PARAMS));

  params->type         = LCM_TYPE_DPI;

  params->width       = FRAME_WIDTH;

  params->height      = FRAME_HEIGHT;

  ... ...

 }else{

  printf("[LK/LCM] [lcm_get_params]->KD116N5_40NV_B12_MIPI enter\n");

  memset(params, 0, sizeof(LCM_PARAMS));

  params->type           = LCM_TYPE_DSI;

  params->width         = FRAME_WIDTH_MIPI;

  params->height        = FRAME_HEIGHT_MIPI;

  ... ...

 }

}

通过uart_log可以看到lvds_select_flag的值已经成功保存到cmdline:

(190418_21:09:30.218)[1392] g_cmdline size: 869

(190418_21:09:30.218)[1392] cmdline: console=tty0 console=ttyMT0,921600n1 earlycon=uart8250,mmio32,0x11005000 vmalloc=496M androidboot.hardware=mt8167 firmware_clas

(190418_21:09:30.218)[1394]        : s.path=/vendor/firmware loop.max_part=7 androidboot.verifiedbootstate=green skip_initramfs rootwait ro init=/init root=/dev/dm-

(190418_21:09:30.218)[1396]        : 0 dm="system none ro,0 1 android-verity PARTUUID=fbc2c131-6392-4217-b51e-548a6edb03d0 " androidboot.slot_suffix=_a androidboot.

(190418_21:09:30.218)[1398]        : slot=a buildvariant=user androidboot.veritymode=enforcing bootopt=64S3,32N2,64N2 buildvariant=userdebug veritykeyid=id:7e4333f9

(190418_21:09:30.294)[1400]        : bba00adfe0ede979e28ed1920492b40f androidboot.atm=disabled androidboot.meta_log_disable=0 androidboot.dtbo_idx=0 printk.disable_

(190418_21:09:30.294)[1401]        : uart=0 bootprof.pl_t=2238 bootprof.lk_t=1359 boot_reason=0 androidboot.serialno=0123456789ABCDEFlvds_select_flag=49 androidboot

(190418_21:09:30.294)[1403]        : .bootreason=reboot mrdump_ddrsv=no mrdump_rsvmem=0x56000000,0x400000,0x42100000,0x180f80,0x54000000,0x80000

(190418_21:09:30.372)[    0.000000] <0>-(0)[0:swapper]KernelKernel command line: console=tty0 console=ttyMT0,921600n1 earlycon=uart8250,mmio32,0x11005000 vmalloc=496M androidboot.hardware=mt8167 firmware_class.path=/vendor/firmware loop.max_part=7 androidboot.verifiedbootstate=green skip_initramfs rootwait ro init=/init root=/dev/dm-0 dm="system none ro,0 1 android-verity PARTUUID=fbc2c131-6392-4217-b51e-548a6edb03d0 " androidboot.slot_suffix=_a androidboot.slot=a buildvariant=user androidboot.veritymode=enforcing bootopt=64S3,32N2,64N2 buildvariant=userdebug veritykeyid=id:7e4333f9bba00adfe0ede979e28ed1920492b40f androidboot.atm=disabled androidboot.meta_log_disable=0 androidboot.dtbo_idx=0 printk.disable_uart=0 bootprof.pl_t=2238 bootprof.lk_t=1359 boot_reason=0 androidboot.serialno=0123456789ABCDEFlvds_select_flag=49 androidboot.bootreason=reboot mrdump_ddrsv=no mrdump_rsvmem=0x56000000,0x400000,0x42100000,0x180f80,0x54000000,0x80000