[Qemu-devel] Re: [Bochs-developers] [PATCH 2/6] Add S3 state to DSDT. Handle resumeevent in the BIOS.

["Sebastian Herbszt" <herbszt@gmx.de>]

Gleb Natapov wrote:
> diff --git a/bios/rombios.c b/bios/rombios.c
> index 88eac04..46996fa 100644
> --- a/bios/rombios.c
> +++ b/bios/rombios.c
> @@ -2198,6 +2198,31 @@ debugger_off()
>   outb(0xfedc, 0x00);
> }
> 
> +void
> +s3_resume()
> +{
> +    Bit32u s3_wakeup_vector;
> +    Bit8u s3_resume_flag;
> +
> +    s3_resume_flag = read_byte(0x40, 0xb0);
> +    s3_wakeup_vector = read_dword(0x40, 0xb2);
> +
> +    BX_INFO("S3 resume called %x 0x%lx\n", s3_resume_flag, s3_wakeup_vector);
> +    if (s3_resume_flag != 0xFE || !s3_wakeup_vector)
> +     return;
> +
> +    write_byte(0x40, 0xb0, 0);
> +
> +    /* setup wakeup vector */
> +    write_word(0x40, 0xb6, (s3_wakeup_vector & 0xF)); /* IP */
> +    write_word(0x40, 0xb8, (s3_wakeup_vector >> 4)); /* CS */

Any reason not to use 0040h:0067h instead?

> +    BX_INFO("S3 resume jump to %x:%x\n", *(Bit16u*)0x04b8, *(Bit16u*)0x04b6);
> +ASM_START
> +    jmpf [0x04b6]
> +ASM_END
> +}
> +
> #if BX_USE_ATADRV
> 
> // ---------------------------------------------------------------------------
> @@ -10005,6 +10030,10 @@ rombios32_05:
>   ;; init the stack pointer
>   mov esp, #0x00080000
> 
> +  ;; pass pointer to s3_resume_flag and s3_resume_vector to rombios32
> +  push #0x04b0
> +  push #0x04b2
> +
>   ;; call rombios32 code
>   mov eax, #0x00040000
>   call eax
> @@ -10383,6 +10412,9 @@ normal_post:
>   rep
>     stosw
> 
> +  ;; Save shutdown status
> +  mov 0x04b0, bl
> +
>   call _log_bios_start
> 
>   ;; set all interrupts to default handler
> @@ -10593,6 +10625,8 @@ post_default_ints:
>   mov  ax, #0xe000
>   call rom_scan
> 
> +  call _s3_resume
> +
> #if BX_ELTORITO_BOOT
>   call _interactive_bootkey
> #endif // BX_ELTORITO_BOOT
> diff --git a/bios/rombios32.c b/bios/rombios32.c
> index f0daf15..ff84f80 100644
> --- a/bios/rombios32.c
> +++ b/bios/rombios32.c
> @@ -180,6 +180,20 @@ void *memmove(void *d1, const void *s1, size_t len)
>     return d1;
> }
> 
> +int memcmp(const void *s1, const void *s2, size_t len)
> +{
> + const int8_t *p1 = s1;
> + const int8_t *p2 = s2;
> +
> + while (len--) {
> + int r = *p1++ - *p2++;
> + if(r)
> + return r;
> + }
> +
> + return 0;
> +}
> +
> size_t strlen(const char *s)
> {
>     const char *s1;
> @@ -644,7 +658,7 @@ static void bios_shadow_init(PCIDevice *d)
> {
>     int v;
> 
> -    if (find_bios_table_area() < 0)
> +    if (bios_table_cur_addr == 0)
>         return;
> 
>     /* remap the BIOS to shadow RAM an keep it read/write while we
> @@ -1461,7 +1475,7 @@ void acpi_bios_init(void)
>     memset(facs, 0, sizeof(*facs));
>     memcpy(facs->signature, "FACS", 4);
>     facs->length = cpu_to_le32(sizeof(*facs));
> -
> +    BX_INFO("Firmware waking vector %p\n", &facs->firmware_waking_vector);
>     /* DSDT */
>     memcpy(dsdt, AmlCode, sizeof(AmlCode));
> 
> @@ -2011,9 +2025,40 @@ void smbios_init(void)
>     BX_INFO("SMBIOS table addr=0x%08lx\n", (unsigned long)start);
> }
> 
> -void rombios32_init(void)
> +static uint32_t find_resume_vector(void)
> {
> -    BX_INFO("Starting rombios32\n");
> +    unsigned long addr;
> +
> +    if (bios_table_cur_addr == 0)
> +        return 0;

BX_USE_EBDA_TABLES case

> +
> +    for (addr = bios_table_cur_addr; addr < bios_table_end_addr; addr++) {
> +        if (!memcmp((void*)addr, "RSD PTR ", 8)) {
> +            struct rsdp_descriptor *rsdp = (void*)addr;
> +            struct rsdt_descriptor_rev1 *rsdt = (void*)rsdp->rsdt_physical_address;
> +            struct fadt_descriptor_rev1 *fadt = (void*)rsdt->table_offset_entry[0];
> +            struct facs_descriptor_rev1 *facs = (void*)fadt->firmware_ctrl;
> +            return facs->firmware_waking_vector;
> +        }
> +    }
> +

RSDP is on a 16-byte boundary

> +    return 0;
> +}
> +
> +static void find_440fx(PCIDevice *d)
> +{
> +    uint16_t vendor_id, device_id;
> +
> +    vendor_id = pci_config_readw(d, PCI_VENDOR_ID);
> +    device_id = pci_config_readw(d, PCI_DEVICE_ID);
> +
> +    if (vendor_id == 0x8086 && device_id == 0x1237)
> +        i440_pcidev = *d;

Please use PCI_VENDOR_ID_INTEL and PCI_DEVICE_ID_INTEL_82441.

> +}
> +
> +void rombios32_init(uint32_t *s3_resume_vector, uint8_t *shutdown_flag)
> +{
> +    BX_INFO("Starting rombios32 %p %p %x\n", s3_resume_vector, shutdown_flag, *shutdown_flag);

Maybe make it two lines and explain the values for the log:

BX_INFO("Starting rombios32\n");
BX_INFO("s3_resume_vector=%p ... \n", s3_resume_vector, ...

> 
> #ifdef BX_QEMU
>     qemu_cfg_port = qemu_cfg_port_probe();
> @@ -2025,6 +2070,24 @@ void rombios32_init(void)
> 
>     smp_probe();
> 
> +    if (find_bios_table_area() < 0)
> +        return;

It should not return if BX_USE_EBDA_TABLES is defined.
Is there a need to return at all?

> +
> +    if (*shutdown_flag == 0xfe) {
> +        *s3_resume_vector = find_resume_vector();
> +        if (!*s3_resume_vector) {
> +         BX_INFO("This is S3 resume but wakeup vector is NULL\n");
> +        } else {
> +         BX_INFO("S3 resume vector %p\n", *s3_resume_vector);
> +            /* redirect bios read access to RAM */
> +            pci_for_each_device(find_440fx);
> +            bios_lock_shadow_ram(); /* bios is already copied */

bios_shadow_init() is called in pci_bios_init(). Why do we need to lock it here?

> +            return;
> +        }
> +    }
> +
> +    uuid_probe();
> +
>     pci_bios_init();
> 
>     if (bios_table_cur_addr != 0) {
> 

rombios32.c r1.32 got:

    smp_probe();

    pci_bios_init();

    if (bios_table_cur_addr != 0) {

        mptable_init();

        uuid_probe();

The patch should remove uuid_probe() from the if-case.

- Sebastian