On Fri, Feb 03, 2023 at 12:04:27AM +0000, Peng Fan wrote: > > Subject: Re: [PATCH V2 5/6] remoteproc: imx_rproc: set Cortex-M stack/pc > > to TCML > > > > On Fri, Jan 27, 2023 at 05:22:45PM +0800, Peng Fan (OSS) wrote: > > > From: Peng Fan <peng.fan@xxxxxxx> > > > > > > The i.MX8M Cortex-M core not has ROM. It has a requirement is the > > > stack, pc value should be set in address 0 and 4 from the view of > > > itself. From Cortex-A core view, the region is at TCML start address. > > > > > > The stack and pc value are the first two words stored in section > > > ".interrupts" of the firmware, and the section is the first section in > > > the firmware. > > > > > > When the firmware is built to run in TCML, there is no issue, because > > > when copying elf segments, the first two words are copied to TCML also. > > > > > > However when the firmware is built ro run in DDR, the first two words > > > are not copied to TCML start address. > > > > > > This patch is to find the ".interrupts" section, read out the first > > > two words and write to TCML start address at offset 0 and 4. > > > > > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx> > > > --- > > > drivers/remoteproc/imx_rproc.c | 37 > > > +++++++++++++++++++++++++++++++++- > > > 1 file changed, 36 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/remoteproc/imx_rproc.c > > > b/drivers/remoteproc/imx_rproc.c index 295e0e0e869a..f5ee0c9bb09d > > > 100644 > > > --- a/drivers/remoteproc/imx_rproc.c > > > +++ b/drivers/remoteproc/imx_rproc.c > > > @@ -7,6 +7,7 @@ > > > #include <linux/arm-smccc.h> > > > #include <linux/clk.h> > > > #include <linux/err.h> > > > +#include <linux/firmware.h> > > > #include <linux/firmware/imx/sci.h> > > > #include <linux/interrupt.h> > > > #include <linux/kernel.h> > > > @@ -23,6 +24,7 @@ > > > #include <linux/workqueue.h> > > > > > > #include "imx_rproc.h" > > > +#include "remoteproc_elf_helpers.h" > > > #include "remoteproc_internal.h" > > > > > > #define IMX7D_SRC_SCR 0x0C > > > @@ -634,6 +636,39 @@ static struct resource_table > > *imx_rproc_get_loaded_rsc_table(struct rproc *rproc > > > return (struct resource_table __force *)priv->rsc_table; } > > > > > > +static u64 imx_rproc_get_boot_addr(struct rproc *rproc, const struct > > > +firmware *fw) { > > > + struct imx_rproc *priv = rproc->priv; > > > + const u8 *elf_data = (void *)fw->data; > > > + u8 class = fw_elf_get_class(fw); > > > + u64 bootaddr = rproc_elf_get_boot_addr(rproc, fw); > > > + const void *shdr; > > > + void __iomem *va; > > > + u64 sh_addr, offset; > > > + > > > + if (priv->dcfg->devtype == IMX_RPROC_IMX8M) { > > > + /* > > > + * i.MX8M Cortex-M requires [stack, pc] be put in address > > > + * [0, 4], so the da address is 0, size is 8 words. > > > + */ > > > + va = (__force void __iomem *)rproc_da_to_va(rproc, 0, 8, > > NULL); > > > + shdr = rproc_elf_find_shdr(rproc, fw, ".interrupts"); > > > + if (!shdr || !va) > > > + return bootaddr; > > > + sh_addr = elf_shdr_get_sh_addr(class, shdr); > > > > This isn't used - why is it still there? > > will drop it. > > > > > > + offset = elf_shdr_get_sh_offset(class, shdr); > > > + > > > + /* > > > + * Write stack, pc to TCML start address. The TCML region > > > + * is marked with ATT_IOMEM, so use writel. > > > + */ > > > + writel(*(u32 *)(elf_data + offset), va); > > > + writel(*(u32 *)(elf_data + offset + 4), va + 4); > > > > Here you are writing 2 words at address 0x0 and 2 words at address 0x4. > > Why are you saying the size is 8 words in the comment above? > > Typo. I should mean 8 bytes. > How can I trust the code in this patchset when the "typo" is so obvious and found in the comment above and 4 times in the changelog? > Thanks, > Peng. > > > > > > + } > > > + > > > + return bootaddr; > > > +} > > > + > > > static const struct rproc_ops imx_rproc_ops = { > > > .prepare = imx_rproc_prepare, > > > .attach = imx_rproc_attach, > > > @@ -647,7 +682,7 @@ static const struct rproc_ops imx_rproc_ops = { > > > .find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table, > > > .get_loaded_rsc_table = imx_rproc_get_loaded_rsc_table, > > > .sanity_check = rproc_elf_sanity_check, > > > - .get_boot_addr = rproc_elf_get_boot_addr, > > > + .get_boot_addr = imx_rproc_get_boot_addr, > > > }; > > > > > > static int imx_rproc_addr_init(struct imx_rproc *priv, > > > -- > > > 2.37.1 > > >