Re: git: 9758dd3de1cd - main - stand: Allocate bootinfo rather than have it be static

On Sat, Sep 17, 2022, 11:01 AM Tijl Coosemans <tijl@freebsd.org> wrote:

> On Fri, 16 Sep 2022 15:54:04 GMT Warner Losh <imp@FreeBSD.org> wrote:
> > The branch main has been updated by imp:
> >
> > URL:
> https://cgit.FreeBSD.org/src/commit/?id=9758dd3de1cddc8271be8dd6fee69286c5c86535
> >
> > commit 9758dd3de1cddc8271be8dd6fee69286c5c86535
> > Author:     Warner Losh <imp@FreeBSD.org>
> > AuthorDate: 2022-09-16 15:09:41 +0000
> > Commit:     Warner Losh <imp@FreeBSD.org>
> > CommitDate: 2022-09-16 15:18:57 +0000
> >
> >     stand: Allocate bootinfo rather than have it be static
> >
> >     This saves 80 bytes (the new bootinfo structure was 84 bytes, and a
> >     pointer is 4 bytes). The bi_load32 code is the same size.
> >
> >     Sponsored by:           Netflix
> >     Reviewed by:            tsoome
> >     Differential Revision:  https://reviews.freebsd.org/D36575
> > ---
> >  stand/i386/libi386/bootinfo32.c | 29 +++++++++++++++--------------
> >  1 file changed, 15 insertions(+), 14 deletions(-)
> >
> > diff --git a/stand/i386/libi386/bootinfo32.c
> b/stand/i386/libi386/bootinfo32.c
> > index 372bced917d6..37a797289f2b 100644
> > --- a/stand/i386/libi386/bootinfo32.c
> > +++ b/stand/i386/libi386/bootinfo32.c
> > @@ -42,7 +42,7 @@ __FBSDID("$FreeBSD$");
> >  #include "geliboot.h"
> >  #endif
> >
> > -static struct bootinfo  bi;
> > +static struct bootinfo  *bi;
> >
> >  /*
> >   * Load the information expected by an i386 kernel.
> > @@ -91,11 +91,12 @@ bi_load32(char *args, int *howtop, int *bootdevp,
> vm_offset_t *bip, vm_offset_t
> >      /* XXX - use a default bootdev of 0.  Is this ok??? */
> >      bootdevnr = 0;
> >
> > +    bi = calloc(sizeof(*bi), 1);
> >      switch(rootdev->dd.d_dev->dv_type) {
> >      case DEVT_CD:
> >      case DEVT_DISK:
> >       /* pass in the BIOS device number of the current disk */
> > -     bi.bi_bios_dev = bd_unit2bios(rootdev);
> > +     bi->bi_bios_dev = bd_unit2bios(rootdev);
> >       bootdevnr = bd_getdev(rootdev);
> >       break;
> >
> > @@ -172,22 +173,22 @@ bi_load32(char *args, int *howtop, int *bootdevp,
> vm_offset_t *bip, vm_offset_t
> >      /* legacy bootinfo structure */
> >      kernelname = getenv("kernelname");
> >      i386_getdev(NULL, kernelname, &kernelpath);
> > -    bi.bi_version = BOOTINFO_VERSION;
> > -    bi.bi_size = sizeof(bi);
> > -    bi.bi_memsizes_valid = 1;
> > -    bi.bi_basemem = bios_basemem / 1024;
> > -    bi.bi_extmem = bios_extmem / 1024;
> > -    bi.bi_envp = envp;
> > -    bi.bi_modulep = *modulep;
> > -    bi.bi_kernend = kernend;
> > -    bi.bi_kernelname = VTOP(kernelpath);
> > -    bi.bi_symtab = ssym;       /* XXX this is only the primary kernel
> symtab */
> > -    bi.bi_esymtab = esym;
> > +    bi->bi_version = BOOTINFO_VERSION;
> > +    bi->bi_size = sizeof(bi);
>
> sizeof(*bi) here and maybe make bi a function variable?
>

Damn. I even looked for those... :(

Warner

> +    bi->bi_memsizes_valid = 1;
> > +    bi->bi_basemem = bios_basemem / 1024;
> > +    bi->bi_extmem = bios_extmem / 1024;
> > +    bi->bi_envp = envp;
> > +    bi->bi_modulep = *modulep;
> > +    bi->bi_kernend = kernend;
> > +    bi->bi_kernelname = VTOP(kernelpath);
> > +    bi->bi_symtab = ssym;       /* XXX this is only the primary kernel
> symtab */
> > +    bi->bi_esymtab = esym;
> >
> >      /* legacy boot arguments */
> >      *howtop = howto | RB_BOOTINFO;
> >      *bootdevp = bootdevnr;
> > -    *bip = VTOP(&bi);
> > +    *bip = VTOP(bi);
> >
> >      return(0);
> >  }
>
>