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Date:   Tue, 28 Aug 2018 13:10:20 -0700 (PDT)
Subject:     Re: [PATCH] riscv: Drop setup_initrd
In-Reply-To: <1533874300-17656-1-git-send-email-linux@roeck-us.net>
CC:     aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux@roeck-us.net
From:   Palmer Dabbelt <palmer@sifive.com>
To:     linux@roeck-us.net
Message-ID: <mhng-7faee2bb-ee3e-48d1-a016-782ebbbb903d@palmer-si-x1c4>
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On Thu, 09 Aug 2018 21:11:40 PDT (-0700), linux@roeck-us.net wrote:
> setup_initrd() does not appear to serve a practical purpose other than
> preventing qemu boots with "-initrd" parameter, so let's drop it.
>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
>  arch/riscv/kernel/setup.c | 39 ---------------------------------------
>  1 file changed, 39 deletions(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 2e56af3281f8..579f58a42974 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -82,41 +82,6 @@ EXPORT_SYMBOL(empty_zero_page);
>  /* The lucky hart to first increment this variable will boot the other cores */
>  atomic_t hart_lottery;
>
> -#ifdef CONFIG_BLK_DEV_INITRD
> -static void __init setup_initrd(void)
> -{
> -	extern char __initramfs_start[];
> -	extern unsigned long __initramfs_size;
> -	unsigned long size;
> -
> -	if (__initramfs_size > 0) {
> -		initrd_start = (unsigned long)(&__initramfs_start);
> -		initrd_end = initrd_start + __initramfs_size;
> -	}
> -
> -	if (initrd_start >= initrd_end) {
> -		printk(KERN_INFO "initrd not found or empty");
> -		goto disable;
> -	}
> -	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
> -		printk(KERN_ERR "initrd extends beyond end of memory");
> -		goto disable;
> -	}
> -
> -	size =  initrd_end - initrd_start;
> -	memblock_reserve(__pa(initrd_start), size);
> -	initrd_below_start_ok = 1;
> -
> -	printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n",
> -		(void *)(initrd_start), size);
> -	return;
> -disable:
> -	pr_cont(" - disabling initrd\n");
> -	initrd_start = 0;
> -	initrd_end = 0;
> -}
> -#endif /* CONFIG_BLK_DEV_INITRD */
> -
>  pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
>  pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
>
> @@ -195,10 +160,6 @@ static void __init setup_bootmem(void)
>  	set_max_mapnr(PFN_DOWN(mem_size));
>  	max_low_pfn = pfn_base + PFN_DOWN(mem_size);
>
> -#ifdef CONFIG_BLK_DEV_INITRD
> -	setup_initrd();
> -#endif /* CONFIG_BLK_DEV_INITRD */
> -
>  	early_init_fdt_reserve_self();
>  	early_init_fdt_scan_reserved_mem();
>  	memblock_allow_resize();

With this patch I can't boot in QEMU.  It might be something with my setup, 
though.  I'm testing with a unified BBL+vmlinux, and using QEMU 3.0.0-rc3 (I 
should probably update that one, but I don't remember anything going by).  Do 
you have time to take a look?  Here's my QEMU commandline

./riscv64-softmmu/qemu-system-riscv64    -nographic    -machine virt    -smp 4    -m 2G    -kernel /home/palmer/work/riscv/riscv-pk/build/bbl -object rng-random,filename=/dev/urandom,id=rng0    -device virtio-rng-device,rng=rng0    -append "console=ttyS0 ro root=/dev/vda"    -device virtio-blk-device,drive=hd0    -drive file=stage4-disk.img,format=raw,id=hd0    -device virtio-net-device,netdev=usernet    -netdev user,id=usernet,hostfwd=tcp::10000-:22

I just tagged the PR I plan to submit for RC2 tomorrow, so at least it should 
be easy for everyone to get on the same page.